I love to see well-established audio companies with a solid lineup on offer. Someone like Parasound, Sennheiser, or PSB will almost always have their bases covered with budget, midrange, and fairly expensive models to choose from. That's great because it allows access for all sort of folks, regardless of budget. But you know what I love even more than that? Growth. Seeing a company, new or old, making continual improvements, is just great to see. Think RHA or Philips - neither is firmly established as a market leader at this point, yet both churn out some very competitive models.... and they just keep getting better each time. That's what I like to see.
 
Another such firm is Hong Kong based Lear. They specialize in custom in-ear monitors, though other things such as universal monitors and headphone amplifiers are also on the menu. I've previously evaluated their entry-level LCM-2b custom IEM and later the LCM-5, finding both to be very respectable in their particular price categories. The LCM-5 in particular has always seemed like a somewhat under-appreciated design, rivaling many of the flagships from other brands and only falling short compared to the very best - which tend to cost more anyway. 
 
Well, Lear is back once more with an even better design - the LCM-BD4.2. At $1400 the BD4.2 takes aim at the best on the market from JH Audio, Noble, Ultimate Ears, and others. Not just another "me too" design or an increase in drivers for the sake of driver count, the BD4.2 is very high-tech in both design and execution - perhaps more so than most any other CIEM on the market today. Let's take a closer look at what makes it so special.
 
Design
"BD4.2" doesn't necessary sound as catchy as V6 or Miracle, but it does have some rhyme and reason behind it. Can't say the same for some others like JH13 (arbitrary number salad). The BD stands for Balanced and Dynamic, which describes the hybrid nature of the design. The 4 means quad balanced armature drivers, while the 2 is for the dual dynamic drivers on board. In the land of very few hybrid designs, this is a standout offering - the closest competitor is Unique Melody's Merlin which uses quad BA drivers with a single dynamic handling low frequencies. Merlin is a very enjoyable CIEM but doesn't really aim as high as the flagship Lear, in either price or execution. 
 
BD4.2 uses dual armature drivers on highs and two on mids, with the dual 6mm dynamic drivers handling low frequencies. A three-way crossover and four individual sound bores keep frequencies separated until they reach the ear canal, preventing them from interacting while en route. Lear uses an acoustic low-pass filter which is extremely uncommon. The only other model that comes to mind is Shure with their latest SE846 flagship. I recall Shure making a huge deal of this feature, calling it "groundbreaking" and promising "previously unattainable" deep bass response. Lear also makes use of metallic sound bores for the mids and highs - Japan's FitEar does the same, claiming improvements in high frequency response as well as a more consistent performance due to tighter tolerances. Internally, the sound tubes for the bass drivers are much longer and more curved than other CIEMs. The only other place I've seen this is with the JH Audio FreqPhase models, so I can only assume it has a similar design goal in terms of phase. And those tubes are incredibly small in diameter, which is said to maintain control and accuracy - this same trick is used in the top models from Noble Audio. It could be that these features constitute the acoustic filter - there's not enough info given to really know for sure, and I assume Lear wants to keep their secrets to themselves. Lastly, we get the adjustable bass system. This is accomplished by a tuning knob and a special (included) screwdriver-like tool. The dynamic drivers on bass duties are the only ones influenced by this adjustment, and I'm guessing it has to do with opening the size of the vent hole which is conveniently placed on top of the CIEM shell. 
 
Go ahead and read that last paragraph again, keeping track as you go of the number of uncommon design cues being implemented. As I said before, this may be the most technically advanced CIEM currently on the market, even if most people don't know about it.
 
The initial design had the vent hole on the faceplate like most other dynamic CIEM designs, and you'll still see pictures of that design on Lear's website. I'm glad Lear discovered the alternate location. One of the dynamic drivers appears to sit very close to the hole, almost as if to block it completely.... but when I look close I see a small gap between them. This is probably deliberate to help keep funk out of the sensitive internals. This also keeps the faceplate clean and allows for more design options which otherwise probably wouldn't work as well. Opening and closing a vent for bass adjustment is reminiscent of the Mr Speakers Alpha Dogs, though in this case it seems easier to do. I would like to have some type of numbering system or other way to insure that both sides are dialed in equally. But with trial and error it is doable. Even so, I don't think Lear intends us to change this every few songs. It's a moving part, and all moving parts eventually fail. So I'd think the goal is to allow a user to find their ideal setting and then, for the most part, leave it there. On the plus side, I didn't notice any lack of isolation compared to my other CIEMs. My particular Unique Melody Merlin has compromised isolation due to the vent, though to be fair most other Merlin owners tell me they don't have any issues. 
 
 
 
 
 
 
 
 

 
 
 

 
 
Looks
Lear offers a fairly large number of aesthetic options. They don't have the most robust customization out there but I'd call it "slightly above average" in that regard. Build quality has always been excellent in my prior Lear models and the BD4.2 is no different - I got mine in a transparent light blue with titanium faceplates, and it looks pretty damn nice. This is the same scheme I used for my Unique Melody Platform Pure 6, and I'd say Lear manages to match UM in build quality - a compliment as far as I'm concerned. Other choices include True Texture (looks like carbon fiber), denim, real wood, glitter, and more. Of course, plain designs in solid or translucent are always available, and we get a choice of three zones for different colors - the tips, the shell, and the faceplate. All in all I think Lear offers solid enough build quality and sufficient customization even if they don't quite lead the field in either area.
 
Accessories
The cable Lear uses is one of the best stock cables I've experienced. They call it the C2 and also sell it separately for around $90, in case someone wanted to upgrade their existing CIEM cable. It's an SPC design (silver plated copper) using high quality materials with a focus on flexibility. Indeed, this is among the most flexible CIEM cables I've tried, short of the ultra-thin Linum cables. It reminds me a lot of the cable being used by Noble Audio, which is another of my favorites. Lear offers the C2 in clear or black, and claims the clear version has a special treatment to avoid oxidation - which happens in most every stock clear cable I've owned, and leads to an ugly green appearance. So far my clear C2 has held up like new despite several months of rather heavy use. Like the Noble cable, it does tend to become tangled rather easily, but I have a system to avoid that (winding around my fingers before storing it away) so I don't mind. The more traditional "Westone style" that most brands tend to use is just as tangle-prone anyway. Lear also offers the alternate MMCX connection style, though I'm not really a fan of that type as I had trouble with it on my old LiveWires CIEMs. 
 
Aside from the C2 cable, Lear gives us a fairly nice presentation: quality Otter Box brand waterproof case, user manual, soft pouch, cleaning tool, screwdriver, cleaning cloth, and a shirt clip. This is more than we typically see from other brands, and helps with the feeling that Lear cares about the total user experience. 
 

 

 

 
 
 

 
Universal version
What's that? A universal variation of the LCM-BD4.2? Yep, Lear apparently sees the writing on the wall - many CIEM makers are similarly coming to the conclusion that universal options are in demand. For better or worse, people really want something they can share, resell without hassle, and not have to visit an audiologist in order to purchase. Opening your designs up to another market brings a broader pool of potential customers, which is always good when you sell a niche item like this. 
 
Lear calls their custom models the LCM series, for Lear Custom Monitors. The universal versions become LUF for Lear Universal Fit - it started with the well received LUF-4 and continued here with the LUF-BD4.2 (like you didn't see that coming....) While the LUF-4 offered 3 flavors (permanent once chosen) in bass heavy, neutral, and bright, the LUF-BD4.2 sticks with a single version - the tunable bass system already covers any adjustments the user may desire. At $1260 shipped, the LUF model is slightly cheaper than the LCM.
 
Lear includes the same accessories as the custom version, plus a good selection of tips. We get several sizes of the "normal" single-flange tips, plus biflange, triflange, foamies, and what appear to be comply style. It's a fairly generous package and should allow most users to find a reasonable match. Other tips can be used as well if you happen to have a favorite. I usually stuck with the medium single flange as those are traditionally the best fit, though I did spend some time with the foamies, comply and biflange, as those all seemed to fit reasonably well. As is usually the case, each tip offers a slightly different seal and thus a different take on the sonic presentation.
 
 
 
 
 
 
 
 
 

 
Equipment
I used the BD4.2 a lot at home but also did more portable listening than usual. At home, the system is comprised of a Surgex XU-115 power conditioner, Aurender X100L music server, Audiophilleo 1 DDC with the PurePower option, Resonessence Labs Invicta Mirus DAC, and a Violectric V281. All cabling is Cabledyne Silver Reference except the AC cables which are from their Copper Reference series. I did do some switching of amps and DACs to get an idea of how the BD4.2 responds to changes.
 
On the go, I used a wide variety of DAPs ranging from a humble Sansa Clip+ to a full AK240/Chord Hugo setup. Steps in between include the HiFiMAN HM-802 with IEM amp card, the Calyx M, a Sony NWZ-A17, and a Fiio X5 paired with the iQube V5. I even used an iPad Air and a Moto X to see how the BD4.2 handles more pedestrian sources.
 
 
 
 

 
Listening
My preference is for custom molded IEMs, so I did all my initial listening on the LCM version. I started with the bass knob at the stock setting which is basically the lowest setting at roughly 8 o'clock. I played a very wide variety of music to get a feel for what worked and what didn't. I later went back and adjusted the bass to various settings until I could figure out how successful Lear's implementation really is.
 
In stock form, the LCM-BD4.2 shared many traits with Sennheiser's flagship HD800. The presentation was somewhat lightweight but extremely detailed and very three dimensional. I don't know that I've ever heard an IEM sound quite so open and airy. Cymbals were rendered beautifully, with gobs of shimmer and very lifelike decay. Piano had a sweetness to it that reminded me of Adam Audio monitors with their X-ART tweeters - excellent extension, virtually non-existent grain, and a sense of ease not often achieved by traditional dome tweeters. This was a great way to listen to Chopin and Sibelius, and tons of fun with Dexter Gordon or McCoy Tyner. The laser-like clarity on the top end deftly walked the line between "accurate" and "bright". Most of the time I heartily enjoyed it but on some recordings I found it to be a bit much. Which again is something in common with the HD800. As far as "neutral" IEMs go, this is easily among the very best I've ever heard. 
 
Still, there were times when I was left wanting for more impact. After all, with two dynamic drivers on low frequency duty, it wouldn't be unreasonable to expect a little more kick. The bass was exceedingly tight and clean, but at times lacking in convincing impact. I found myself skipping certain genres, especially classic rock (which is sometimes a little thin on its own compared to modern stuff). I also found myself turning the volume up more than usual to bring out more warmth, only to find the highs too sharp at those higher levels. Clearly I needed to mess with that bass tuning knob. Which leads me to my next point...
 
If there's one change I would make on the BD4.2, it would be to more clearly label the bass adjustment. I've already mentioned this but it bears repeating: as it stands, there's a vague graphic which makes it clear whether I'm turning the bass up or down. But it doesn't really help when trying to precisely match one side to the other. To make matters worse, only my universal pair, and not the custom set, has this graphic - presumably an oversight when my demos were made. Even so the graphic is not all that helpful. Perhaps a numbering system would work, or even just dots so I could know exactly how far I've turned it and match both IEMs evenly. This would be an easy fix going forward and I hope Lear can see the benefit in implementing it. 
 
Anyway, I settled on a moderate setting about halfway between minimum and full blast. I rambled through various classic rock favorites from Moody Blues, Hendrix, Traffic, and of course one of my all time favorites, King Crimson. The sonic character was now distinctly more weighty, with excellent low end extension and some real thump taking place... when appropriate, of course. I also had fun listening to somewhat newer (but still not "new") bands like Soundgarden, Pearl Jam, Stone Temple Pilots, Smashing Pumpkins, and Eloy - many of whom have discographies spanning several decades by now. Eloy actually started in the early 1970's and their last album came in 2009, bridging the gap between these two categories - somehow I missed them completely until their last few releases, so I tend to think of them as a newer band even though that's not true at all. Again the extra low frequency energy gave a real sense of impact, imparting a more dynamic, musical experience as compared to the earlier setting. This made it much more comfortable with low-volume listening, and I no longer struggled with brightness. 
 
I later went all the way up to the max bass setting and was surprised to hear it did not unbalanced the rest of the spectrum. The bass gets positively massive and frankly way too much for my tastes, but even so it doesn't intrude where it doesn't belong. This has some serious potential as a basshead CIEM, though for some reason I assume the target market there will want a smoother, more forgiving presentation as with the Noble 5C. Maybe I'm wrong. The takeaway here is that Lear really succeeded with their adjustment system. It seems to have something for everyone, with no drawbacks in sight other than the previously mentioned logistical issue. 
 
But.... full blast is just too much for me. I went back to my "middle-ground" setting because it seemed best for my preferences. I found it worked well with all sorts of music - from challengingly complex jazz by The Bad Plus to the bare-bones "To Be Alone With You" from Sufjan Stevens' somewhat under-appreciated Seven Swans, the BD4.2 generally offered a successful balance of resolution and soul. It had the requisite energy on Tiesto's "Battleship Grey" and the proper restraint on Secret by Polish jazz songstress Anna Maria Jopek. With the extra low end kick I find the BD4.2 to actually be more versatile that my HD800... and if I ever run into a situation where I feel the added lows negatively impact my listening, I can always cut some out. Did I mention I love this versatility?
 
Summing up the presentation so we can move on: deep, punchy bass with exceptional texture and refinement. It hits tight and clean or (much) harder if you tell it to, and never bothers the other frequencies. Midrange is what I'd call neutral - it's got a pleasing tonal weight to it without being overdone, and a clarity normally associated with a thinner, more detail oriented IEM. I'd call it "honest" if that makes any sense. Among its most exciting traits, the BD4.2 has an extremely spacious soundstage, up there with the very best available from a CIEM. It creates a sense of space that few competitors can match. And the highs? Very natural, clear, resolving, with just a slight emphasis that seems most obvious when the bass knob is turned down. It's interesting how, perceptually, the highs relax a little once the extra bass kicks in, even though I know they aren't actually changing. I don't get any sense of grain or peaks, though with the bass set to minimum the highs do sometimes end up being more prominent than I'd like. Lastly, the sound is what I'd call organic, meaning it all acts remarkably like a single full range driver despite the complex mix of BA and dynamic drivers on board. Ultimately the BD4.2 is a very precise, very satisfying CIEM.
 
 
PAIRING
I want to touch for a moment on what types of gear work best with this CIEM - it's of a high enough caliber where it really shows the differences between sources, much like an HD800 (there's that comparison again). I had a great time using it with both desktop and portable systems but I notice it's pretty brutal in exposing poor sources. I tried it with my Moto X Android phone and the result was noticeably flat and lifeless as compared to even a humble Sansa Clip+. I also concluded that even with a solid desktop system, the BD4.2 excelled at showing off recording quality as well as format weaknesses. So lossy streaming from Amazon Prime Music (256Kbps MP3) was pretty much off the menu, and Rdio (320Kbps AAC) was acceptable if not quite spectacular. Lossless streaming from Orastream and Tidal was as good as an actual CD, meaning the key factor then became the recording/mastering itself. A modern loudness-wars era pop track won't be too impressive even when played on a quality setup, so if that's your main diet you can look elsewhere. On the flip side, DXD material available from Promates.com were nothing short of breathtaking, as were the many excellent recordings I tried from NativeDSD.com. On the DXD release of Carl Nielsen's Symphony No. 4 (as played by the New York Philharmonic) the timpani battle is truly something to behold - the BD4.2 handles it with seemingly effortless poise, showing that dynamic drivers can be every bit as fast as their armature counterparts. The DSD release of Britten's epic War Requiem culminates in the beautiful "Libera me", with the Lear in-ear monitors just oozing emotion. These types of releases are a bit pricey, but the performances are stunning and the result is sheer ear candy through quality equipment. 
 
I have to mention that NativeDSD has a sale going on through January for 15% off - use code "2015-15off" and grab a few things. Most every new DAC boasts DSD capabilities so why not take the format for a spin? I find it to have a sense of ease not usually found even with hi-res PCM, and with NativeDSD you can be sure you get true DSD from DSD masters, complete with metadata. I simply can't recommend them highly enough. Sure, the format still caters to a specific type of music at the moment, but I'd challenge you to step outside your comfort zone and give it a shot. You'll be glad you did!
 
That said, one can simply grab some reasonably good recordings in 16/44.1 FLAC format, play them from a humble Sansa Clip+ or Fuze, and the result is still pretty impressive. And it only gets better from there - the $299 Sony NWZ-A17 made a particularly good match without breaking the bank, and of course the Calyx M and AK240 were even better... as they should be for the price. My favorite portables ended up being the Calyx, the HM-802, and the Fiio X5 paired with the new iQube V5 (review coming soon) as they all had a somewhat more musical, organic tone compared to the slightly crisper AK240 or Chord Hugo. Those still worked well (especially for resolution junkies) but for my tastes the top end on the Lear doesn't need any extra zing.
 
At home, I had similar results. The BD4.2 favors a very controlled or even slightly dark treble presentation as compared to more lit up sources. Aurender's new FLOW, paired directly with their X100L music server, handled the job perfectly, as did the Parasound Zdac V2 feeding a NuForce HA200. You don't need a ton of power to drive these, so it's more important to have a solid grip even at low volumes. Here big amps like the Questyle CMA800R or Auralic Taurus don't fare as well, with their gain more suitable for full-size models. The usual caveat about needing a low output impedance definitely applies here.... the 10 ohm output of the Zdac V2 amp section does some weird things with the frequency response, and not for the better. A 2 or 3 ohm output impedance won't be a dealbreaker but I wouldn't go much higher than that - this is a really complex multi-driver setup and that's just asking for trouble. 
 
 
 

 
COMPARISONS
Lear's own LCM-5 is a very good CIEM and I still rather enjoy it. But the BD4.2 makes it sound a little primitive in comparison.... which is a big deal because, again, the LCM-5 is no slouch at all. The BD4.2 keeps a similar signature (depending on bass settings of course) but seems more refined in the treble, leading to less aggressive highs but no loss of apparent detail. In fact I think the newer model digs even deeper into the musical landscape - it just does so in a smoother, more confident manner. The LCM-5 has somewhat more forward mids which makes it jump out as being more direct and energetic. I initially thought that might be an advantage but after a short time I concluded the hybrid was more natural sounding, more true to the actual musical event. Bass on the LCM-5 is great if not quite on the level of heavy hitters like JH13 FP - BD4.2 kicks it up more than a single notch, showing Lear can truly compete with world class competition. LMC-5 is still a very good CIEM but falls just short of the best in a few areas, while BD4.2 is truly reference caliber.
 
Speaking of the JH13 FP.... I find it similar to the new Lear in a few ways, but different in others. Both have heaping amounts of sparkle up top. Both image like crazy, both offer a very convincing soundstage experience. The JH13 FP has some extra kick which can be matched by turning the Lear just a bit beyond half way on the bass knob. Interestingly, I don't notice huge differences in bass quality between the two models, despite them using very different approaches for drivers. The Lear may be a tiny bit more articulate and if pressed I'd call it the winner.... but the difference is small. For the most part both do an exceptional job. Where they part ways is the transition from mids to highs. JH13 has some extra upper midrange energy, making it more aggressive and jumpy. The Lear is more mellow in that respect, but counters with a little more air in the highest registers. This results in the unusual situation where the Lear is more laid back in some ways, yet more bright in others, depending on the music being played. For the most part I'd call the BD4.2 a more neutral, reference sounding IEM, especially if we back off on the bass tuning. Both are extremely enjoyable but I find myself reaching for the Lear more often lately - high praise indeed.
 
Lastly, the Unique Melody Merlin, which could be logically considered a competitor due to the hybrid design. Well, logic or not, I don't really see them as competitors - the Lear is in another bracket entirely. It simply outdoes the Merlin in pretty much every meaningful metric. I love my Merlin, don't get me wrong, but this is another situation (like the Lear LCM-5) where direct comparison makes the BD4.2 sound that much better and leaves the competitor sounding a bit worse than usual. Again, this is high praise, and not necessarily something I saw coming. A welcome surprise I suppose. 
 
UNIVERSAL SOUND
I have to say I'm not really accustomed to universal IEMs these days. I was a regular user back when that's mainly all you could get - I had the Shure E500 and the UE Triple Fi when they first came out, and later the Westone UM3X. These seemed like big purchases back then (if only I knew how much I'd be spending in the future....) and they sounded great for their time. But I never quite got into the comfort of any of them. Westone was probably the best for my ears, but it still caused me discomfort as time went on. I could do a half hour no problem, but 45 minutes or an hour was pushing it. Throbbing ear canals forced me to give up my listening if I tried going much longer than that. 
 
Now that I've become totally reliant on custom IEMs, I find myself unable to do even a half hour with universals. 20 minutes is about my limit. Perhaps I could probably do longer if I used them exclusively and built up a tolerance. But really.... no thanks. Anyway, the LUF-BD4.2 is an interesting universal in that the shape doesn't seem quite as user friendly as other models. It's probably due to all the drivers and technology packed inside, but these aren't small by any means - they actually aren't much smaller than the custom molded version. I have fairly large ears and the LUF still doesn't fit all the way flush. It's not as goofy as the UE TF10, but neither is it low profile like a Westone or other modern designs. This meant I could listen at home for 20 minutes at a time, but I didn't really leave the house with them at all. The last universal CIEMs I tried were the Aurisonics ASG-1 (which had an angle on the nozzle that didn't agree with my ear canal) and the Noble 6 (which was so small that it practically disappeared into my canals). Neither of them worked perfectly for my ears, which again goes to show how good custom molded IEMs are for my particular needs.
 
Anyway, the LUF-BD4.2 was interesting in that it seemed more tip dependent than most any IEM I've tried. Performance levels approaching the custom version were elusive - I thought I heard it a few times, but for the most part there were issues. Sibilance, flat soundstage, muffled highs, boomy bass..... each set of tips would solve one problem but introduce another. The tips that seemed most comfortable tended to be the worst as far as sound quality, and vice versa. One of my favorite aspects of the custom version - the huge, three dimensional presentation - seemed to be consistently smaller no matter what tips I tried. Perhaps with different ears I could have made it happen but in my case it simply wasn't meant to be.
 
In the end I wasn't sold on the universal version as it pertains to MY particular ears. There's lots of potential there - I did get brief glimpses of greatness - and I wouldn't take this as a blanket evaluation. It's simply a bad match on my part. The nature of a universal means hopefully one could try them out before committing to buy, making sure the fit is not an issue. If one happened to get a good fit, this could end up being a really good universal after all.
 
CONCLUSION
Lear has a real winner on their hands when it comes to the LCM-BD4.2. The name is a mouthful to be sure. Get past that and you've got yourself a marvel of advanced IEM design, perhaps beyond anything else on the market right now - this is certainly not a case of merely adding more drivers and bumping the price, which is a charge often leveled at new flagship releases. 
 
Does that make it my favorite CIEM? It's definitely in the running. Honestly, I tend to prefer the warmer, smoother sound signature of the Noble Kaiser 10, much like I prefer the LCD-3 to the HD800 most of the time. Yet I recognize there are things the HD800 (and BD4.2) can do that are simply better, making them the preferred choice in some instances. If your sonic preferences lean more towards the analytical, detailed side of things, or if you already love the HD800 and want a somewhat similar presentation in CIEM form, the LCM-BD4.2 should absolutely be on your short list of contenders. And if you've struggled to enjoy the HD800 signature, wishing it was slightly less bright or thin..... the BD4.2 should really be on your list. I can't think of another CIEM that better captures this essence. Very enthusiastically recommended! 
 

 
 
 
Integrated amplifiers. We all know what they are, right? The classic definition involves having a power amplifier and a preamplifier integrated into the same chassis. Hence the name. It used to be very straight forward - you could walk into a brick and mortar store, or browse an audio catalog/website, and easily see the distinction between power amps, preamps, and other devices such as DACs. When grouped together each category had generally the same capabilities and features.
 
Nowadays things aren't so simple. Many "integrated" amps now feature one or more digital inputs, thus blurring the line between integrated amp and DAC. I see reasonably priced options from Cambridge and Marantz, step up models from Rotel and Parasound (in their Halo range), and true high-end designs from the likes of McIntosh and Devialet, all of which have a full selection of both digital and analog inputs. Some of these devices even have headphone jacks, giving them potential for true all-in-one status. Add a computer (or disc transport if you want to be old school), speakers and/or headphones, and you're all set. 
 
Unfortunately, the headphone jack on most of these types is rather questionable. I can forgive that sort of thing on a Marantz PM6005 or a Cambridge Audio 651A, both of which clock in at well under a grand. The issue is more with expensive models - users who pay two or three thousand dollars on something upscale may have the gall to think they have correspondingly high-quality headphone amplification on board. But I rarely come across an integrated with a headphone out exceeding the performance of, say, a $250 Matrix M-Stage dedicated headphone amp. Not saying it doesn't exist... it's just exceedingly rare. Interestingly enough, a quality headphone outputs seemed a lot more common place on vintage devices from Pioneer, Sansui, and other. Seems we've gone downhill - on the whole, I'd say the headphone side of these things could use some serious work.
 
But wait - don't most DACs these days have built in volume control? They sure do. That opens up the field quite a bit right? Stuff like the Benchmark DAC 2 variants, Anedio D2, and even the affordable Yulong Audio D200 - all have plenty of digital inputs as well as preamp capabilities either in the digital or analog domain. And on the plus side, these have far more credible headphone outputs. We trade out the speaker amp section though, and we don't always get analog inputs or remote volume control. Plus a lot of people think these types of DACs don't do an adequate job driving an amplifier directly. There's a large number of people I've spoken with who find them too sterile. Squeaky clean. Lacking in "grunt" to use a technical term. It's not necessarily a volume issue but more a problem of tonal density and richness. Many feel that adding a dedicated preamp to the mix does wonders for adding realism and weight to the final result. Same DAC, same amp, same speakers.... the weak spot must be the DAC and its ability (or lack thereof) to drive those amps directly. I can't say my experience lines up perfectly with this theory but I might agree on a case by case basis. One doesn't have to browse audio sites very long to find pro reviewers and consumers alike who agree with this assessment and thus hang on the their preamps. 
 
Stay with me here, because I've got a point to all this discussion. Say you're an audio designer and you want to offer a really high quality all-in-one device. You can't make it huge so you've got to pack everything in a reasonably sized enclosure. A superb DAC is an absolute must - you've already got a reference caliber DAC in your stable, so you end up using that as a reference and packing in as much of that technology as possible. Since this is HeadFi, you're extremely concerned about the headphone amp quality as well. The usual simplistic opamp output or voltage divider from the speaker amp simply won't do. Luckily you already have an exceptional headphone amp in your lineup, so again you try to cram most of that design in this magical box as well. This leaves you with very little room for anything else. You make sure the preamp section is up to snuff, with analog volume control via motorized potentiometer so a remote can be included. You provide a reasonable amount of inputs and outputs - as many as will be allowed given your size constraints. And that's pretty much all we need right? Wait, we forgot the speaker amplification section.... 
 
The product in question does exist. It's called the CMA800i from Questyle Audio Engineering. Maybe I'm just overly concerned with semantics, but for some reason I'm really intrigued with what Questyle has going on here. It's essentially a modern integrated amplifier with a focus on digital inputs rather than analog, but it swaps out the speaker amplification for a very potent headphone stage based on the highly regarded CMA800R headphone amp. The DAC stage is based on their CAS192D which again is known for being extremely high quality. The logic here is that most of us are primarily concerned with headphone amplification and wish to build a system around that aspect. And yet we may want to add speakers to the mix at some point as well. The CMA800i makes a fantastic preamp for dedicated amplifiers or active speaker systems, and fits right in at the heart of a semi-complex system in a way that most DACs can't - even those modern DACs with volume control on board.
 

 
 

 
 

 
 

 
The CMA800i ($1,999) comes very close to being a CMA800R headphone amp ($1,499) plus a CAS192D DAC ($1,499) stuffed in one box. Each design is very well represented with minimal compromise despite having less real estate. We lose a few inputs on the digital side, and we don't get the option of doubling up for a dual mono amp setup as we do with the dedicated CMA800R. We also lose the display on the DAC side, making do instead with LED indicators to show filter selection. In exchange we get remote capabilities and output voltages more in line with a proper preamp than with a regular DAC. Ever notice most DACs, including those with volume controls, go to around 2V via RCA outs, and 4V from XLR? That's plenty for a lot of situations, but it's also significantly less than many dedicated preamps. Those creatures commonly top out at 7V or 8V or even higher at times. Along those lines, the CMA800i does 4.3V via RCA out and 8.6V on XLR. That may end up being more than needed but then again we can simply lower the output in those cases. On the flip side, a DAC with 2V RCA outputs cannot go any higher, and thus may end up being a poor match with certain amplifiers depending on the voltage gain involved. Try to pair that DAC with an amplifier having a mismatched input sensitivity, and you won't be able to drive the amp to its full unclipped power. This is more common with higher power amplifiers but you just never know - to make matters worse, this number is not always easy to find with all amps. Bottom line - the higher output option covers all the bases which is why we see it more often in "true" preamp devices.
 
 

 
 
 

 
 
 

 
 

 
Specifics
The CMA800i has just enough going on to make it fit in most systems. On the input side we get a high quality USB input with 24/192 PCM capabilities and Questyle's proprietary TrueDSD implementation which handles DSD64 and double data rate DSD, aka DSD128. We also get a coaxial SPDIF input with the usual 24/192 PCM status. There's also a single RCA analog input on the off chance you want to use some other source, or perhaps a vinyl setup (separate phono preamp required, obviously). For outputs we get RCA and XLR analog outs as well as a coaxial SPDIF output which forwards the transcoded USB data, just in case someone had a use for that. And of course the pair of 1/4" headphone outputs on front. Counting the headphone jacks, we get a total of 3 inputs and 5 outputs split fairly evenly between digital and analog. Not the most feature packed integrated I've ever seen in this area, but it should do the trick for most systems. 
 
 
 

 
To dig deeper into the specs: Digital inputs are converted to analog by Wolfson's flagship WM8741 with your choice of two custom digital filters. TrueDSD mode deactivates any digital filtering as Questyle prefers to handle that in the analog domain. A proprietary USB receiver handles incoming signals - Questyle works with a famous chip maker to customize their solution, tweaking it to their specific needs. You'd probably recognize the source chip if I named it, as it is used in several very popular DACs on the market right now. Like the CAS192D and other quality USB DACs, CMA800i features three independent custom low phase-noise clocks. It also uses a proprietary chip which looks to me like an FPGA - as was the case with their CAS192D, Questyle doesn't want their design completely revealed. How mysterious. Again we get a Wolfson WM8805 SPDIF receiver, Plitron toroidal transformer, and extensive voltage regulation with independent power supplies for different functions. And of course the device uses the proprietary Current Mode Amplification which I discussed in THIS review. It's all pretty much what I've come to expect from Questyle based on my experience with their gear. And notice how many times I used the words "custom" and "proprietary".
 
 

WM8805 digital receiver
 
 

Proprietary Questyle chips 
 
 

WM8741 DAC chip
 
 

Headphone amp section
 
 

Analog section
 
 

Digital section
 
 

 
The motorized Alps RK27 potentiometer is controlled by a remote that initially looks somewhat low rent, but is actually fairly nice to use. Contrast it with some of the competition who loves using giant slabs of metal for their wands - confidence inspiring, but not very fun to use considering the weight and the tiny buttons. This particular remote is nearly identical to the one used by B.M.C. for their highly-regarded PureDAC device.
 
 
 

 
 
Use
Rather than using my usual reference headphone rig, I instead took the CMA800i straight to my 2-channel setup. I fed it with an HP Elitebook laptop over USB - it's a reasonably modern device using a Haswell i7, 16GB RAM, and large SSD. I also pulled in music from my 8TB NAS, ranging from Redbook quality to DSD128, and used JRiver Media Center for playback, controlled via iPad Air using JRemote. I occasionally used a YBA Design WM202 as transport for the coaxial input. XLR outputs went to a pair of Ghent Audio M500P monoblocks using ICEpower technology, which in turn fed a set of Sjofn Clue loudspeakers. Of course, I also used the headphone outputs with a wide variety of headphones, including LCD-2, HD800, T1, HE-500, and many more. Ancillary equipment included a CablePro Revelation power strip, Cabledyne Silver Reference interconnect and digital, Cabledyne Copper Reference AC, and Charleston Cable Company Auric speaker cables.  
 
 

 
 

 
 
 

 
 
 

 
 

 
 
The last few dedicated preamps I've had in this system were significantly more expensive than the CMA800i. I was using a Meridian G02 for a while, and prior to that was a Jeff Rowland Design Group Capri. I happen to still have both on hand for comparisons. Both of these devices cost roughly double the CMA800i and both are pure analog only..... so the value is definitely tilted towards the Questyle device when we consider features. On build quality, the Capri has the usual Rowland aesthetic, and the Meridian is quite striking as well. The CMA800i is very well built and rather handsome in general but it does suffer a bit from having too many knobs, switches, lights, etc, all over the front panel. Still, this is a matter of style, not a strict downgrade. So that leaves us with sound quality - should spending more for a device with less features net significant SQ improvements? In this case: not particularly.
 
First off, I found the Capri to be outclassed by the other two models in this particular system. It just sounded a little veiled and soft in comparison. I initially had thought this was my Sjofn monitors not being detailed enough - but after swapping to the Questyle I see that was not the case. 
 
The Meridian sounded very, very similar to the Questyle. In fact I don't think I could reliably tell them apart in this context. I used the CMA800i as DAC to feed the G02 to keep things fair, and I just didn't spot any significant areas of variation worth mentioning. This speaks very highly of the Questyle as the G02 is known to be a top notch preamp. Of course, there are more inputs and outputs and the famous Meridian name to consider.... Interestingly, when I swapped out the Ghent Audio ICEpower monoblocks for a Parasound Halo A21, the Rowland was back in the mix, sounding a lot more similar to the others. I don't know why it was such a poor match the first time around - especially considering Rowland makes ICEpower amps themselves. This shows me once again that you can't just throw together a system and expect greatness, even if each individual component is reasonably well regarded. Synergy is definitely at play in certain combinations, and a lack of synergy in others.
 
I later brought the three devices to my main headphone rig and used each to drive the Questyle CMA800R monoblocks (which work best with volume controlled via preamp or DAC) feeding a balanced HD800. This combo is extremely resolving and detailed, far more so than my speaker rig, and it helped differentiate the character of each device. Turns out they do have differences. The Questyle sounded a bit thinner than the Meridian in the lower midrange, making it less punchy and dynamic. But it did seem more revealing of microdetails and subtle nuances found in excellent recordings. In a word, the Meridian was more "dramatic" and the Questyle more "refined". The Rowland seemed more midrange focused with a very lush, involving presentation, but less extension than the other two on top and bottom. This time around I did find it enjoyable - it's interesting how much of a difference a preamp can really make in shaping your final sound quality. I hesitate to pick an absolute winner of these three, which again is complimentary of what Questyle has accomplished.
 
I imagine some readers wonder when I'll get to the point. "Forget all the semantics about integrated amps, or preamplification, output voltages, Current Mode Amplification, blah blah blah. I just want to use this as an all in one DAC and headphone amp. I don't care what you call it. How does it sound with headphone X, Y, and Z?" I can understand that line of reasoning so I'll cut to the chase... or at least, try not to ramble so much.
 
I continued with the HD800 which had paired so well with Questyle's dedicated headphone amps. Sure enough, I got very impressive results straight from the CMA800i. This was an extremely transparent, clean, fast combination that did a bang up job with quality material, and really showed how poorly done many newer recordings are. I loved going through my reference catalog playing Kind of Blue, Dvorak, Haydn, Jacintha, and a bunch of others from Channel Classics, Reference Recordings, Harmonia Mundi, Blue Coast, and other fine labels. If we define "realism" as the ability to hear deep into the recording, including subtleties and microdetails and all those little things.... the CMA800i driving HD800 is up there near the best I've ever heard. There was, however, a very stark contrast when I played some modern overcompressed music on this system - as much as I enjoy Further Seems Forever, Infected Mushroom, BT, Mastodon, etc, a lot of that stuff is borderline unlistenable on an HD800 with a really transparent system. Realistically - if you play a lot of poor recordings you shouldn't be using an HD800 in the first place. An LCD-2 will do a much better job. But if you insist on an HD800 and you spend a lot of time with those types of recordings, none of the Questyle gear is really a good match for you.
 
The Grado PS500 is my favorite modern Grado (I have yet to hear the new "e" version) and the CMA800i drives it with fantastic results. It has all the fun I enjoy from the Grado signature while minimizing (though not quite eliminating) the drawbacks. I broke out my Steve Hoffman remasters of Metallica's Ride the Lightning and Master of Puppets and played them all the way through, marveling at how we went from gems like this to Death Magnetic in just two decades. The CMA800i does nothing to stifle the signature Grado "bite" or midbass warmth, and when I tried a borrowed set of SR-325is I did not like the result at all. But again that comes down to the headphone itself - CMA800i is not one of those devices that "improves" a Grado by smoothing it or otherwise changing it. You get the true Grado sound, like it or not. I don't normally consider myself a huge Grado fan but this experience has inspired me to seek out a vintage RS-1 or HP-1000, as well as try something from the new "e" series. 
 
I went back and forth with the Audeze LCD-2 and HiFiMAN HE-500 - both are well done, but the LCD-2 sounds better for my preferences in this particular application. The speed and resolution of the Questyle really complements the somewhat laid-back LCD-2 signature, and while HE-500 is still enjoyable it ends up being a little on the bright side at times. Both models have nice bass impact, and both sound very open and fairly expansive. But it's that top end that really differentiates them for me - the HE-500 seems to have a mid-treble peak that gets fatiguing after a short time, and the CMA800i certainly does nothing to hold it back. I have other amps which favor the HE-500 but in this case Audeze takes the win. I did try the HiFiMAN HE-6 and got mixed results - it's not terrible, certainly still listenable, but also very obviously missing out on the supposed world-class performance of that headphone. This was the single largest difference between the CMA800i and the dedicated CMA800R - the power rating doesn't change by much, yet somehow the integrated model loses the ability to shine with this admittedly difficult challenge. 
 
If you've read my thoughts on the CMA800R, you'll recall how it was pretty much a no-go for sensitive in-ear monitors. There's an ever-present hiss, and the gain is just way too high, leaving very little usable room on the volume knob. No big deal, a lot of big amps have issues with IEMs. So I wasn't expecting anything better with the CMA800i. But to my surprise, it actually works much better this time around. Perhaps Questyle got the memo that IEMs and custom IEMs are big business now. The gain is still fairly high but at least I can get to 9 or 10 o'clock on the dial before it gets too loud. And the background is nice and clean - no hiss to be found. As I turn up the volume (with no music playing) I do hear a faint but increasing bit of noise, but it's well outside the bounds of what I could tolerate while the music plays. So I was able to successfully enjoy my Noble Kaiser 10, JH Audio JH13Pro, and other top custom in-ear monitors, in a way I never could on the dedicated CMA800R. I consider this a big deal because I love CIEMs and use them frequently at home rather than just on the go like some people do.
 
After all the swapping of preamps I did earlier, I was already spending more physical effort on this review than usual. But my work was not yet done. I figured the best way to really do justice to this device was to compare it with the stand-alone amp and DAC models from Questyle. To make matters even more complex, I wanted to see if the CMA800i was equally strong in all aspects. So I mixed and matched CMA800i with CMA800R and CAS192D to get a sense of how each function stacked up to the reference. To make a really long story slightly less long, the CMA800i comes pretty darn close to the individual components. Maybe 90%, give or take. The individual components add up to $3,000, yet the CMA800i sells for $2,000 - a significant savings considering the small compromise involved. Aside from the previously mentioned HE-6 challenge, the amp side really only stumbles when asked to handle exceedingly complex material, and even then only by a small amount. Unless you're a fan of dense symphonic works or certain jazz, the differences are small enough as to be nearly indistinguishable.
 
On the DAC side, the stand-alone model again holds a very tenuous advantage. I confess I do miss the handy OLED display, and I think the CAS192D looks quite a bit nicer due to the clean front panel. I also miss the ability to track incoming sample rates - the integrated unit has LED indicators to differentiate PCM from DSD signals, and that's it. The CMA800i only has two digital filters but the IIR option is still present and that's really all that matters as it was my favorite out of the original five choices. Again, when using really dense, really high-res material I might notice some worthwhile improvement with the dedicated unit. Instrument separation and layering is somewhat better and the sound is more coherent overall. But much of the time it's hard to tell them apart. 
 
As with the CAS192D, this device sounds absolutely ravishing when playing DSD. I don't know if I necessarily agree with Questyle's negative assessment of the DoP process used by most other devices, but I have to admit - their particular handling of DSD is among the best sounding I've yet heard. While some DSD material is no better than Hi-Res PCM (and indeed many "DSD" releases are simply repackaged PCM anyway), some of it actually does live up to the hype. If you have an adventurous taste in music and especially if you enjoy jazz and classical, it's definitely worth exploring.
 
Any complaints to speak of? I've already mentioned the front panel looking somewhat busy, and even then it doesn't contain every bit of info I might want. I'd also like to see a Toslink input to replace the coaxial SPDIF output - the USB to SPDIF conversion makes sense on their more affordable Q192, but I just don't see much use for that function in a device of this caliber. And as with CAS192D, DSD playback is limited to JRiver on a Windows system at the moment which is a potential downside for some users. And lastly, the filters can only be switched by using the remote. These minor complaints are really the worst I can come up with.... and none of them are serious problems. Then again it helps to recall the Questyle signature across the board - it's fast, detailed, and very accurate, which isn't always the best match for every situation. Listeners wanting a warm, creamy midrange or mellow highs will not particularly like this presentation. You've been warned. 
 
Conclusion
The Questyle CMA800i is a very clever device. Whether we consider it a cutting edge integrated with a focus on digital inputs and headphone amplification, or just call it an all-in-one headphone amp/DAC/preamp device like so many others on the market, the end result is the same - a versatile device with exceptional sound that can take a central role in most any audio system. When I recall how much I like the individual Questyle flagship components, and then consider how close the CMA800i comes to that level of performance, for much less cash... it's an easy recommendation for anyone seeking extreme levels of accuracy and refinement. It even does some things better, like playing well with sensitive IEMs. 
 
There's a lot of competition in this space. The BMC PureDAC is excellent and costs a bit less, and then there's the Benchmark DAC 2 and Grace Design M920, and probably others that I'm missing. Unfortunately I didn't have any of those here for direct comparisons. I will say the BMC falls on the warmer, smoother, more "analog" side of the spectrum, making it a very different animal than the CMA800i. Still, I don't recall any of these knocking me out in ways the Questyle does not. Most others tend to start as a DAC and then add a headphone out as a sort of bonus - Questyle starts with a genuine high-end amp, avoiding that "afterthought" syndrome. 
 
I hope Questyle continues to innovate, and I hope even more that they get more exposure in the USA. I anticipated more online distribution but apparently they want to go in a different direction, using brick and mortar stores instead. That wouldn't necessarily be my choice but hey, nobody asked me. If you find yourself intrigued and want to know where to find one of these devices, contact Questyle North America rep Bruce Ball to find out where to look.
 
 

Driving dual CMA800R monoblocks and feeding the HiFiMAN HE-6
 
 

Topless
 
 

With YBA CD transport
 
 

More Monoblock action
 
 

More eye candy
 
 
With Ghent Audio monoblocks in my speaker rig
 
 

This review is one of the most difficult I've had in quite some time. Not because the product had flaws, or because I couldn't make sense of what I was hearing (which sometimes happens), but because I struggled to understand the concept behind the design. I'm still not totally convinced that I have a handle on it, but I know some people are waiting to read this so it's time to move forward regardless. The product in question is the CMA800 headphone amplifier from Questyle, which is a new company hoping to take off in a big way. Based on what I've heard so far I think they have a good chance of succeeding. 
 
 

 

 
 
 
Chinese firm Questyle Audio Engineering has been working on this particular design for over 6 years, going through a total of 22 different revisions before achieving what they believe is a ground breaking, reference class headphone amplifier. We'll talk about this particular implementation shortly, but first a bit of background on current drive amplification in general.
 
I'm going to paraphrase Tyll Hertsens because I think he has a knack for explaining complex things in simple terms. In a current drive amplifier (aka transconductance amplifier), the input voltage causes the amplifier to deliver a proportional output current. The output stage of the amplifier will do anything it needs to in order to deliver a current signal that matches that of the audio input, feeding it straight to the voice coils of the connected headphones. It's the current in the voice coils that actually drives the diaphragms, so this type of amplifier creates a very linear relationship between the incoming audio signal and the physical response of the driver. A byproduct of current-mode amplification? The traditional damping factor, which we all know and love, no longer applies. Headphone impedance essentially becomes irrelevant. Or at least that's one theory. Others insist that current drive amplification would only work properly with a headphone that has a completely flat impedance curve. But that doesn't really matter in this case, as the CMA800 actually has a voltage output, despite using current mode operation internally. Confused? I sure was. Still am to some degree, though I can't argue with the results I'm hearing - regardless of the path taken to achieve them.
 
Let's take a closer look at the CMA800 ($1499). The CMA stands for "Current Mode Amplification", and Questyle describes their implementation as a four part process - an input buffer, a current transmitter, a trans-impedance amplifier, and finally an output buffer. These stages collectively form what Questyle calls a TransLinear Loop Circuit. The key benefit of such a design - it avoids transient intermodulation distortion (TIMD) which according to Questyle causes unpleasant, metallic sounding highs (which is historically a complaint leveled at solid state gear, often from lovers of tube amps). For the longest time I was under the impression that Questyle used a true current-mode output, much like the Bakoon HPA-21. Though my contact there did a fine job at explaining things, I somehow misinterpreted what he was saying, or perhaps I had a preconceived notion of what to expect. After much discussion, their engineers broke it down for me with some in-depth information. English is not their first language but they do a much better job than I would do if I tried speaking their language! What follows is directly from Questyle, with a few minor corrections for readability. I don't normally like to post manufacturer info directly but in this case it makes sense to do so. Some of the charts got a little fuzzy during formatting, sorry about that.
 
 
 
1) Super Linear theory
In 1975 Mr. Barrie Gilbert created the “Translinear-TL” theory, and published in ISSCC . This marks the birth of Current Mode theory. A translinear (TL) circuit is a circuit that carries out its function using the translinear principle. In TL principle, ideal BJT Collector Current’s log domain (Lc) and Vbe graph is a straight line. See below graph, BJT Collector Current increase from 1pA (1E-12) to 10mA, which is a billion times increase, while log (lc) and Vbe is a good straight line. Current Mode circuit is using this super linear feature to make up a TL loop. This is the basic theory for Current Mode ultra-high precise, ultra-low distortion function.     .
 

 
 
2) Ultra-high speed
In Current Mode circuit, the inter-electrode capacitors in between transistors which affect speed and band are working in a very low impedance point (usually several ohms or dozens of ohms, which is hundreds or even thousands of times less than a voltage mode amplifier). With large amplitude current wave, the inter-electrode capacitors complete their charge and discharge cycle very fast, so the efficiency is much higher than that of a voltage mode circuit.    
 

 
 
 
CMA800 Work Principle
 
Since 1989 in the 87^th AES forum, when Dr. D.C Wadsworth first point out current mode circuit in audio can achieve ultra-high speed, ultra-low distortion function, people start ceaseless dedication towards current mode amplification. So far some brands created CAST (Current Audio Signal Transmission) technology, SATRI technology based BPM7110 modular, etc. These are pioneers on developing current mode technology application on audio. But they are mainly “non-feedback” mode, mainly for current mode “transmission” rather than amplification. Questyle is different, as we specially focus on “amplification” instead of “transmission”, so CMA800 provides more outstanding specifications and sound performance.     
 
 

 
Above is the CMA800 current mode amplification circuit diagram. The circuit is consist of VCCS (Voltage Control Current Source), A(i) --Current Mode amplification modulator, I/V converter, OPT and Negative Feedback sections. In an electronic circuit, both voltage and current are exist - neither can be missing. CMA800 signal is controlled by current so as to provide high performance, while the input and output are in voltage mode. This is to ensure better compatibility with other audio devices.   
 
From the diagram we can see, input signal will first to to VCCS, voltage mode is converted to current mode here, then goes to Ai for amplification (in current mode), next go to I/V converter to become voltage mode again, and output to OPT stage to drive headphone. 
 
For better performance, in this circuit loop we applied Negative Feedback design. The impedance of the whole Negative Feedback loop is in the hundreds of ohms, meaning amplification is very fast; thus the Negative Feedback process speed can be as much as 100 times faster than that of voltage mode designs. In this way CMA800 is free of problems like TIMD or other which occur in voltage mode designs.
 
CMA800 Full-Power Bandwidth approaches Closed-loop bandwidth, and the converting speed shows a linear increase as input signal amplitude increases. These features are totally different from that in voltage mode, and together they support CMA800 to achieve ultra-low distortion and ultra-high efficiency.    
   
The workmanship
 
  Current mode amplification internal translinear-TL loop has critical requirement on transistors. A Canadian semiconductor manufacturer, Microsystems International Limited, had attempted to make a current mode amplification IC but failed on workmanship.
In a TL loop consisting of 6 transistors, a mismatch as small as 5uV Vbe will create 0.01% harmonic distortion. Precise matching is critical. Questyle engineers studied over 5 years on this, working together with Dr. Charles from California university who is dedicated on transistor workmanship research. By selecting from lots of customized specific components, and designing specific circuit structures, we finally achieved success.      
 

 
 
1KHz@300Ω , THD vs Power
 
 
 
 
 

 
1KHz@300Ω , Po=10mW FFT Spectrum Analysis
 
 
 
 
Intermodulation Distortion (IMD)
 
  Some engineers use Sine waves to test amplifier performance. They think that as long as the THD+N value is not high, it should therefore be a good amplifier. But in actuality each music signal is made up of thousands of harmonic waves - it’s expected they will interfere each other, so IMD value is a more fitting approach to indicate signal accuracy as opposed to THD+N. “IM (Intermodulation)” means two or more signals that come together which will interfere with one another and make up a new signal. IMD decides amplifier’s purify, density and details. CMA800 IMD spectrum is almost as perfect as AP2 signal source - we hardly see any mixtures at all.     
 
 
 

 
TIMD @300ohm 0dBV FFT
 
 
 
 
Full frequency low distortion
 
  Ultra-wide bandwidth provides amplifier with great sound, but ultra-low distortion is also required for high frequencies. Otherwise the sound will be terrible. CMA800 distortion graphs at all frequencies show a straight line; the value is ultra-low.   
 
 

 
Po=25mW @300Ω,  
 
 
 Broadband High-speed Amplification
 
  Only an amplifier with broadband high-speed amplification can properly recreate a burst pulse wave signal, accurately reproducing the necessary speed and clarity. CMA800 frequency response is essentially a straight line, with only a -0.3dB drop at 200KHz.   
 
 

Frequency Response @300ohm, 0dBV 
 
 
 
Specific Power Supply
 
For an analogue amplifier, power supply plays a very important role. We work together with Plitron Manufacture in Canada Their senior designers specially designed many versions of dedicated transformers, evaluated and selected the best one to fit our needs. In addition, CMA800 adopts schottky rectifiers to reduce noise, as well as 22 instances of 35V 1000uF Nichicon FG capacitors providing clean power.  
     

 
 
Components
 
  CMA800R adopts best Hi-end components to ensure best sound. Here “best” means best fit, like OPA627 operational amplification module, DALE military resistor, WIMA customized capacitors, Alps volume potentiometer, Nichicon FG capacitor, etc.     
 

 
 
Sound Performance
 
  Besides good parameters, good components, a good sound performance is the last step but most critical factor. Before production, CMA800 was tested with various headphones, and was sent to many studio engineers and musicians for critical evaluation. Once they were all satisfied with our sound, the CMA800 detailed specifications were then fixed and we started production.   
 

 
 
Chassis  
  
Mechanical resonance will affect performance for any Hi-end device. CMA800 chassis is made up of pure Aluminum with “mutual bit” structure, 10mm thick. Each section weight is equal, for maximum reduction of resonance. Feet are made of solid aluminum as well     
   

 

 
 
 
Wow, lots of good info in there. Worth noting: Questyle has an Audio Precision AP2722 (a $30,000 audio analyzer) with which they measure every amp before shipping it out. Each customer is provided a printout showing the results of their specific unit. Pretty cool. In general terms the amp is listed as having a signal to noise ratio of 120 dB, and a real world THD+N figure of 0.0004% @ 1kHz (20mW into a 300 ohm load). That's impressive no matter how you slice it. Setting the TIMD issue and the current-mode operation aside, this is a very well done amp with excellent performance characteristics. The picture shown below is from Questyle's test bench, featuring two of their new CMA800R monoblocks. 
 
 

 

 
Externally, the CMA800 is very nicely done. The look is simple and classy and vaguely reminiscent of the Luxman P-series headphone amplifiers - not bad company if you ask me. The layout is very straightforward - XLR and RCA inputs, dual 1/4" headphone jacks, switches for power and input toggle... and that's pretty much it. A few status LEDs show the user what's going on without being overly bright (which I appreciate). The enclosure, binding posts, and switchgear seem commensurate for this price class and the whole thing is very well built. There's a definite Ayre vibe to the design - not identical or obviously a clone, but they go in the same direction for sure. I find it very tasteful and clean looking. If I must find something to complain about I'd pick the pointy "feet" on the bottom. They aren't really sharp like the spikes used for speakers, but could still do some damage to shelving as well as other components if you stack the amp on top. But they look pretty nice so I suppose it's not a complete loss. 
 

 
The spiky feet, sitting on some audiophile puck I had laying around:

 
Powerful enough to happily run two headphones at once:

 

 

 
LEDs are not too bright - a good thing!

 
Rear panel with XLR and RCA inputs:

 
 

 
Opening the top cover reveals the CMA800 to be packed full of goodies. The first clue hinting at Questyle's ambitions is the power supply - large Plitron brand toroidal transformer flanked by 10 ultra-fast recovery rectifiers and a massive array of Elna Silmic II capacitors, which are often considered to be a top choice for high-end audio applications. I see some opamps making up part of the "TransLinear Loop Circuit" but they have custom "C800" markings so I didn't know their specifics until Questyle mentioned in the above text (they turned out to be the well regarded OPA627, which is one of the most expensive opamps available). Questyle claims a pure class A operation, with output listed as 170mW at 300 ohms, 700mW at 64 ohms, and 1100mW into 32 ohms. It can swing 20 volts peak to peak and has a bandwidth of DC to 650kHz (-3dB). Output impedance is extremely low, to the point where it is a non-issue. 
 
 
A quick note about availability - Questyle seems very serious about breaking into the market. International sales are currently handled through eBay but aggressive pursuit of distributors is currently underway, including plans to show at CES in January. In the CMA800 thread we had a buyer whose amp was somehow damaged during shipment, and Questyle took care of him immediately - he remains a satisfied customer. This is certainly no fly by night OEM. 
 
Now, about the sound....
 
 
When discussing this review with the folks at Questyle, they seemed very concerned about the quality of the source I'd use while evaluating their amplifier. I assured them I had quite a few very nice options to choose from. Despite that, they insisted on sending along their CAS192 DAC ($1,999) to make sure I got the most from the CMA800. The two make something of a matched pair, rather visually striking, though again I dislike the spikes on bottom from a functional standpoint. I had to use some tweaky audiophile footers to keep them from scratching anything. That aside, their CAS192 is an exceptional DAC. It's not the focus of this article, so I'll just say it's very transparent, open, and natural sounding. Definitely competitive with the best I've encountered in that price range or even beyond. I used it for the majority of the review process, though I also swapped in the Resonessence Labs Invicta, NuForce DAC-100, Anedio D2, and BMC PureDAC. The CMA800 worked well with all of them. My contact at Questyle did mention the idea of utilizing current-mode signal transmission (from component to component) as seen in Krell equipment for example. This is not something they want to do for now, because it would mean their DAC becomes exclusive to their amp and vice versa - neither would work with equipment from other brands. Someday, when Questyle is more well known and can thus justify that kind of behavior, it may be an idea they reconsider. Audio GD offers both their proprietary connection as well as separate, standard XLR or RCA options - though they do point out that their ACSS is the best option to use when possible. So that's an idea Questyle could maybe consider.
 
 
Some shots of the matching CAS192 - the CAS stands for "computer as source":

 
Selectable upsampling uses different methods for 44.1kHz and 48kHz signals:

 
 

 
It can also disable upsampling, plus has multiple filter options:

 
Other DACs I used included the BMC PureDAC:

 
The Yulong DA8 (pictured here playing DSD):

 
Source was my Auraliti PK90 music server with NuForce LPS-1 power supply:

 
I also tried multiple DAC options from Resonessence Labs:

 

 
Questyle tells me the amp was designed with the Sennheiser HD800 in mind; hence the name CMA800. I figured that was a great place to start so I grabbed my HD800 and got to listening. I played some tracks from the Reference Recordings HRx Sampler. Holy smokes! Talk about clarity.... Yikes. You want air up top? Tonal accuracy? Well defined transients? The CMA800 really gets that ring radiator jumping, and the result is one killer combo. I've always thought the HD800 was pretty much the best headphone out there for peering deep into the mix of a recording, and the CMA800 brings out that aspect better than just about any other amp I've tried. It practically begs you to throw your most demanding music at it. The complex tone poems of Strauss? Check. The deceptively elaborate IDM masterpiece "Trace" by Gridlock? No problem. The precision polyrhythms of Meshuggah? Bring it on. The team of CAS192/CMA800/HD800 resolves this stuff like pretty much nothing else I've experienced this side of a megabuck electrostatic setup. If detail is your thing, I can't imagine doing much better than this. I like the term "unforced clarity" - there's a complete lack of grain, and details are abundant, but they come with a sense of ease like it's no big deal. "Hi. I'm Detail. This is my friend Accuracy, and my other friend Resolution - we're sort of a team. We'll just be sitting here doing our thing. You can ignore us if you want, or not. Whatever."
 
Now, I can anticipate what the reader might be thinking. Detail is great and all, but what about emotion? What about musicality, the "feel" of the performance existing as something more than a lifeless reproduction? It's true that the HD800, in stock form, will probably never suit certain listeners and their preferences. Nothing we can do to change that unless we modify the headphones to achieve a different sound. For its part, the CMA800 stays well clear of the cold, analytical presentation the HD800 can have when paired with the wrong amp. It remains spectacularly detailed which I use as both a positive and potentially negative description. But that detail is accompanied by very fast and tight bass reproduction which can hit quite hard when called upon to do so. It's definitely not the same thin sound I've heard from the HD800 so many times in the past. This fullness of note results in probably the best compromise between "accurate" and "fun" that I've yet heard from the HD800. Questyle's current-mode amplification process seems to have an iron grip on the drivers and does an exceptional job of reigning them in to avoid excessive harshness, but I have to be honest - these headphones will still be a bit too bright for some people, no matter what amp is used. 
 
The Audeze LCD-2 makes a perfect counterpoint to the HD800. It has that smooth, somewhat thick sound signature that I can spend hours listening to, just melting away the day. Again the CMA800 proves a worthy match. The LCD-2 can sometimes come across as overly dark or slow, but I hear neither of those issues when using this particular amp. While the cheapest Audeze is still not a soundstage champion, the CMA800 helps it sound more open and expansive than most other amps. And that bass that caused so many of us to fall in love with Audeze in the first place? Yep, it's there. Deep, layered, up there with some of the best I've ever heard. Vocals? Those too are very well done, not distant at all which is a problem when using lesser amps. Everything just seemed to fall into place and I found myself wondering how much better the more expensive Audeze options could possibly be - but I've got an LCD-XC on the way so I'll find out soon enough.
 
To get an idea of how black a background is, my favorite test track is John Cage's 4:33. Sounds ridiculous, but I'm dead serious here. Sure, I could simply crank the volume knob to full blast with no music playing, but that doesn't quite recreate the same conditions as when the system is actually in use. In this case, both the HD800 and LCD-2 show no signs of noise until the volume is almost at full blast. I can't quite call it a completely silent amp because there is a tiny bit of hiss or hash present at full output. But I would never get even remotely close to this level even with a super-demanding headphone and quiet music. So for all practical purposes the amp is essentially silent, even if not quite so under extreme conditions. 
 
Speaking of demanding - I tried out the HiFiMAN HE-6 to get an idea of how the CMA800 performs with difficult headphones. I've got to be honest - with most amplifiers, the HE-6 seems a bit lackluster.... not worthy of flagship status in my mind. It's a little on the tizzy side, somewhat thin sounding, and just kind of bland overall. This applies even to some very good amps such as the Icon Audio HP8 mkII. Fortunately the CMA800 is able to wring some musicality out of them - I don't know if it's the current-mode amplification at work or just a byproduct of the excellent specs in general. Either way, the HE-6 as heard through the CMA800 is something I can actually enjoy. A lot. The bass, which seems anemic at times with many other amps, is solid and punchy. The midrange is nicely open and transparent. Those highs are still prominent, and at times it can become fatiguing depending on the recording. But with this combo I feel more confident in blaming the song itself than the headphones, at least in most cases. Of all the amps I've paired with the HE-6, this is up there in the top three along with the AURALiC Taurus and Violectric V200. Not bad company I'd say. Would more power be welcome? Sure. There's plenty of gain here but I do here more grunt with the beefier AURALiC in the chain. But the differences are not as big as the power specs would suggest. 
 
I kept on going, trying various headphones to see what sort of character I could flush out from this device. I had many highly enjoyable moments along the way, while finding just a few minor points to complain about. The CMA800 made the Grado PS500 sound better than any amp I had previously tried. It did a bang up job with my difficult to drive Smeggy Thunderpants, and energized my beyerdynamic T1 like few others can. With the Ultrasone Signature Pro, the sound quality was outstanding, but I had very limited play in the volume knob. Things got really loud, really fast. Which brings me to one of my complaints - the gain seems a bit higher than it needs to be. 
 
The Signature Pro is a rather sensitive headphone, perhaps more so in practice than on paper, and it didn't take much turning of the dial before I found myself maxed out. And that came at around 11 o'clock on the dial. That's not a lot of play between zero volume and too loud, making it tough at times to dial in a comfortable level. Less sensitive headphones work well enough but even the very insensitive Thunderpants and HE-6 only use maybe 60 to 70 percent of the dial with most recordings. If those beasts don't come close to maxing out the knob, nothing will. I'd like to see the gain drop low enough to where an HE-6 gets crazy loud at 4 o'clock (5 o'clock being roughly the highest the amp will go), and most others get loud around 1 or 2. That way most of the dial is used and volume more easily managed. The CMA800 is not alone in this area (the Apex Peak has very similar behavior) but it's something Questyle could address.
 
My other complaint is a relatively common one with big, powerful amps. Sensitive IEMs bring out some hiss, making the CMA800 not well suited for those types. The actual sound is excellent, and if I use a less sensitive model like the Lear LCM-5 with their 180 ohm "Sound Tuned Adapter", I get a glimpse of what could be - and it sounds mighty fine indeed. But I have very little patience for hiss. Factor in the high gain and this just isn't an amp I'd recommend for IEM users. 
 
However, I would enthusiastically recommend the CMA800 for most everyone else. It's one of the most transparent amps I've experienced, and is extremely useful for hearing minor differences between various DACs or CD players. It's not as focused on leading edges and transients as the Apex Peak/Volcano duo, but reminds me more of the L-2 parafeed tube amplifier from ECP Audio in that it shows a level of resolution that few amps - regardless of price - can hope to match. Yet isn't the least bit edgy or fatiguing which is something a greatly value in my gear. There are amps out there with a more exciting signature (like the AURALiC Taurus, review coming soon), and some that sound more spacious (the Eddie Current Balancing Act for example), but overall the Questyle CMA800 seems worthy of competing with this bunch. Any one of these could legitimately qualify as a "desert island" or "end game" headphone amp, so it's impressive to see the CMA800 play on this level.
 
COMPARISONS
My only potential hesitation is one that I commonly encounter when the gear gets this high end. It has to do with value per dollar. Now, we can argue all day about what constitutes a worthwhile expenditure, but in the end I think most people agree that the value-per-dollar apex comes somewhere significantly lower than $1500. In my view it hits hardest around the $400-600 range. There we find the Lake People G109, NuForce HAP-100, DarkVoice 3322, Little Dot MKIV SE, HiFiMAN EF-5, Burson Soloist SL, and any number of others. Between these various models you can essentially drive any headphone from the most sensitive IEM to the most beefy planar, and everything in between. Once you move up from there you do get improvements, but not keeping in step with the money spent. Even within one brand, it's not possible to achieve: the exceptional Violectric V200 at $999 is not twice as good as its sibling, the Lake People G109 ($500). Is it better? Sure. In many ways. But twice as good? Nope. This discrepancy only continues as we go higher and higher up the food chain. I doubt even Pete Millett himself would describe his own flagship Apex Pinnacle amp as being 5 times better than his Peak amplifier with Volcano PSU. It may be one of the best amps in the world, but 5 times better is simply not possible when the Peak/Volcano is already so good. Yet it's that last bit of extra performance that is so difficult to achieve, and thus people are willing to pay big money to get it. Keep that in mind as I compare the Questyle CMA800 to some of my other high-quality amps in the $1K+ price bracket.
 
Violectric V200
The V200 is the obvious comparison here, as I've long championed it as one of the best amps out there while still keeping a "sane" price. And indeed it does not feel completely outclassed by the CMA800. The two are very different, with the V200 having more grunt and gusto, while the CMA800 has a more delicate, nuanced presentation. I'd call it more balanced, faster, more accurate up top, and generally of a higher resolution overall. The V200, with 8 transistors per channel, does bass like few other amps out there, and the CMA800 does give up a bit of ground in terms of visceral, pants-flapping bass reproduction. That's not to say it doesn't have some thump of its own - the CMA800 lights up the LCD-2, the Denon D7000, the Thunderpants, like few other amps can. But I wouldn't say that aspect is really the focus. On the flip side, the Questyle amp has a distinct advantage in terms of wide open, breathtaking soundstage. If imaging is your thing, this contest is over quickly - Questyle takes the unanimous victory. There's also the matter of transparency - I do love the V200 but the Questyle does seem more faithful to what I imagine the original recording should sound like. The Violectric has a slight but definite signature that it imparts on everything it plays. It's a very enjoyable signature, but nonetheless is not something we would seek out when looking for the ultimate in transparency. In its defense, the V200 is still more enjoyable with the HiFiMAN HE-6. I love the resolving power on display with the CMA800, but the V200 gives the HE-6 a signature more agreeable to my personal tastes. 
 
It may sound like I'm sidestepping the comparison, but these two amps really are very different. The V200 is undoubtedly the better value - lower price, plays better with sensitive IEMs, and has more power for planars. And it has a more fun signature as well. The Questyle does the "HiFi" thing better though, and I suspect would be considered the superior amp by a lot of listeners (but certainly not by all).
 
Yulong A18
Once again, two very different amps. The A18 is warmer, smoother, more forgiving, but does nearly match the CMA800 when it comes to spaciousness. This comparison really hinges on the headphones being used. With something like a Grado RS-1, I'd take the A18 every time. While the Questyle does a great job not adding grain to the presentation, the RS-1 is still an inherently  aggressive headphone. So personally I like to take some of that edge off, and the A18 does it more tastefully than any amp I've heard. But if we switch to a Grado PS-500, things change and I actually prefer the Questyle. The PS-500 is the first Grado I've tried where I actually want to hear everything it has to offer. There's no need to smooth it out, tame it, or anything like that. I've owned the PS-1000, HF-2, RS-1, and GS-1000 (plus some of the Prestige series models like SR-325), and none of them satisfied, but PS-500 actually does. I have yet to experience the vintage HP-1000 models or the rare PS-1, but thus far the PS-500 is by far my favorite. It still sounds great with the Yulong A18 but I prefer the clarity and detail the CMA800 has to offer. 
 
If we keep switching headphones, we keep ending up with different results. LCD-2 definitely sounds better with the Questyle. So does HD800, HE-500, and V-Moda M100. HE-6 is a close call but I believe the A18 takes the victory with the more robust low end and smoother highs - though I can see how someone else might disagree because the CMA800 has more detail. K550, Focal Spirit Pro, and Thunderpants all do better from the Yulong. IEMs are a tossup because neither amp seems ideal for them. The A18 has some type of "class A hash" in the background, which only appears with sensitive IEMs but makes for an annoying experience. The CMA800 has a tiny bit of this but the main problem is gain - there's just too much of it. It's very difficult to dial in the proper volume levels when the slightest touch of the knob results in several decibels worth of increase or decrease. The CMA800 ends up being more usable than the A18 but frankly I'd take the V200 over bother of them in this situation; the adjustable pre-gain option makes a world of difference.
 
AURALiC Taurus mkII
This is a tough one because the Taurus mkII is probably the best solid state amp I've ever heard thus far. It costs a few hundred dollars more than the CMA800, but has more features such as preamp functionality, balanced headphone output, and a lot more power. Both are phenomenally well built and very attractive. I went back and forth many times and the differences between these two are subtle - very much more difficult to spot than in the prior amp comparisons. Both are extremely resolving, neutral, well extended on both ends, and very open sounding. After much comparison I believe I found some small differences, though again these are way more alike than they are different.
 
First of all, the Taurus seems to have two distinct sounds to it. The single ended jack is more direct, more dynamic, more lively. The balanced output seems more nuanced and subtle, with more expansive soundstage and more precise imaging. In comparison, the Questyle is closer to the balanced output of the AURALiC - both are what I'd call neutral, clear, and highly resolving. The CMA800 takes a very slight lead when it comes to timbral accuracy - it goes a bit further in making me believe I'm hearing a real instrument. Especially with the HD800, which I still feel is its best match. I also thought the CMA800 did a little better when handling complex orchestral works. Maybe it's the "zero TIMD" thing, or some other attribute, but it seemed absolutely unfazed by even the most ridiculously complicated performances. From Mussorgsky's Night On Bald Mountain, to Stravinsky's Firebird Suite, to L'Apprenti Sorcier by Paul Dukas, and many many others (not to mention highly technical jazz, electronica, metal.... I could go on) the CMA800 just seems to have more honesty and instrument separation, and thus better layering. 
 
Is it a slam dunk for the Questyle? Sorry, no. The Taurus has a sound of its own and I love it for what it is - I actually prefer the single ended jack to the balanced most of the time, especially with certain headphones. It's like taking the warmth of the V200, and the smoothness of the Yulong A18, mixing in a dash of precision from the CMA800, and ending up with a delicious cocktail of great sound. But more on that when I (finally) review that amp at InnerFidelity (soon). If forced to choose between them, I'd have an extremely difficult time. If my rig was HD800 only I'd choose the Questyle. If it was HE-6 only I'd choose the Taurus. The possibilities branch off from there - don't get me started on DAC pairing.... I'll just conclude by saying both are exceptional, and really are the two best solid state amps I've ever heard. I've got the Questyle CAS192 DAC and I've heard the AURALiC Vega DAC, and hearing those just reinforces the notion that these are two excellent companies at the top of their game. AURALiC has been around a bit longer and seems to have made significant inroads towards becoming a somewhat well known and respected brand here in the USA. I'm sure Questyle would like to do the same, and so far they are on the right track.  
 
 
CONCLUSION
What more can I say? This whole current-mode amplification thing seems to be quite the trick. Or maybe it isn't - judging an entire design concept by a single example probably isn't the best thing to do. All I can say with confidence is that the Questyle CMA800 is an exceptional headphone amplifier. I place it in the upper echelon with some of the best amps I've ever heard regardless of price. The clarity is simply intoxicating - a real open window to the music - and seems limited only by the headphones being used. This level of transparency is usually only heard in top level tube amps, which tend to be larger and more expensive than this little solid state wonder. Recommended? Yes, very much so. 
 
That was supposed to be the end of this review. But Questyle, a very aggressive and forward thinking company, has already gone and replaced the CMA800. But not really.... allow me to clarify. The new CMA800R phases out the original model. It's essentially the same amp but with some added features - the most intriguing of which is a single 3-pin XLR output on front, in addition to the dual 1/4" jacks. What does one do with a single 3-pin output? Don't I mean a 4-pin XLR for balanced operation, as seen on the Yulong A18 and AURALiC Taurus among many others? No, actually I don't. I said 3-pin and I meant it. Questyle intends the CMA800R to be a modular, dual mono, true balanced amp. Buy one at a time (the price remains the same), use it like the original CMA800, and you'll love it. But get the urge to upgrade and you can later add another CMA800R to the chain, each one powering its own individual headphone driver. Output from the XLR is fixed for precision matching, which means an external preamp or a DAC with digital volume control is necessary. Questyle calls it the world's first true balanced dual mono headphone amp. I'm not sure if they are unaware of the new Woo Audio WA-234 monoblocks (which do seem to have launched prior to the CMA800R), or maybe they know something I don't about the internal design of that product... maybe it goes down to single-ended, then converts back to balanced prior to output, like the Bryston BHA-1? I don't know. In any case, that's a $16,000 device, and the pair of CMA800R amps is $3,000, so they aren't really competing anyway. I may be able to get my hands on that set for a separate review, but in the meantime: by adding features (there's also pre-amp outputs, slightly increased power capabilities, lower distortion, etc) and not increasing the price, Questyle again shows how serious they are in becoming a well-known player on the scene. I'm impressed, and hope to try out the monoblocks soon. If just a single amp already sounds this good..... 
 
 
 
Note - this review originally appeared under the "CMA800R" category. My mistake. Now that I'm posting a review of that model, I had to create the proper entry and move this review over. 

 
 
 
 
Questyle Audio Engineering has thus far received lots of attention for their CMA800R headphone amplifiers. And rightfully so - those amps are extremely nice, a veritable match made in heaven for the Sennheiser HD800. But Questyle doesn't limit themselves to just headphone amps. No, they are a diverse company with expertise in many other areas. For example - a lossless wireless amplifier system for speakers (available with ICEpower monoblock amplification). That device may not fit the HeadFi demographic but it sure looks unique.... I don't recall seeing much else like it on the market. Thus, I can see why "headphone amp" still jumps to mind when we hear the Questyle name, similar to how I think "amps and pre-amps" when I hear the name Parasound. But Parasound has made lots of other great stuff over the years as well, and currently offers one of the finest CD players on the market in my opinion, the Halo CD1. So it's best to keep an open mind when considering these things. 
 
Questyle also does D/A conversion - I covered their Q192 all in one headphone amp/DAC/pre-amp at InnerFidelity and found it to be very impressive when paired with the right headphones - not a ton of drive for difficult headphones, but simpler loads are great and IEMs are spectacular. At $649 it's a relatively affordable all-in-one and I definitely recommend it. But what about a more upscale system? Questyle's CMA800R is $1500 and can be combined to make a $3000 dual mono, fully balanced setup. As good as the Q192 is, we'll want to take full advantage of the very resolving CMA800R with a true high-end source. Enter the Questyle CAS192D ($1500).
 
Much like the CMA800R is an update of the original CMA800, the CAS192D stems from the original CAS192, with some additional tweaks The main difference? DSD capability. Can't release a new high-end DAC without that these days, can you? Questyle has a twist with their DSD implementation which I'll get to later. But first, some specs and technical info. 
 
DESIGN
The CAS192D is a pure DAC - no volume control, no headphone amp on board. Those are common features in competing products and I tend to hear mixed opinions about the idea. Some find them highly convenient, while others won't ever use them and therefore see them as a waste of resources. I myself could go either way depending on the quality of the implementation in question. Regardless, Questyle chose to do this particular design as a pure DAC, so if you need those features you'll have to look elsewhere (or wait for the upcoming CMA800i which essentially combines CMA800R and CAS192D in one integrated chassis). 
 
 

 
 
While not having volume or headphone amp capabilities, most other expected features are on board. We get a choice of 5 digital filters and defeatable upsampling, allowing for a certain degree of customization to the sound. An OLED display keeps us in the loop as to incoming sample rates and selected options. Around back we get Toslink and coaxial inputs rated for 24-bit/192kHz, and asychronous USB matching that same rate plus adding DSD capabilities. For outputs we get XLR as well as RCA, with both active at the same time. There's really not anything missing except an AES/EBU input - I see less and less of those these days, but I know some folks still value the format. 
 
 
 

 
 
 

 
 
 

 
 
 
As for build quality, the CAS192D matches the CMA800R in terms of styling and general workmanship. Which, the way I see it, is a generous compliment. The CNC machined aluminum enclosure looks and feels like something nicer than your typical "affordable" DAC, and again I point out a very Ayre-esque look to the whole affair. My review unit has the older CAS192 branding (no D) but contains the updated internals. It looks quite nice stacked with one or two CMA800R amps - almost like they were made for each other (which, of course, is true). 
 
 
 

 
 
Note the thick panels - this picture doesn't really do it justice:

 
 
Internally, the CAS192D is based around the WM8741 which is the top chip from Wolfson Micro (recently purchased by Cirrus Logic), and is also seen in the popular PS Audio PerfectWave DAC series. Questyle lists Wolfson as a "technology partner" and works in conjunction with their engineers, which means designs have been given a good double-check by qualified experts. Questyle applies their patented Current Mode Amplification system to reduce transient intermodulation distortion (TIMD), which they state reduces digital glare and hardness. The output stage is based around the excellent AD8599 opamps from Analog Devices. Questyle uses their own badging on the receiver chip for USB input - it's a tweaked version of a well known chip used in a few other currently popular DACs. I was able to successfully guess the model (I'm good like that) but to respect Questyle's wishes I'll keep it under my hat. Questyle uses a triple clock structure (or 3X as they call it) meaning three separate ultra-low phase noise clocks for USB, 44.1kHz, and 48kHz and their multiples. There's also a special Questyle branded chip next to the USB receiver, which I suspect is an FPGA used for jitter reduction. Questyle prefers to keep that under wraps... fair enough. But they do say it routes PCM and DSD signals along different paths in keeping with their "True DSD" philosophy (which I still haven't explained, but I'll get to it). 
 
 

 
 
Relays on the outputs:

 
 
Mystery chip (likely an FPGA):

 
 
Proprietary USB implementation:

 
 
Output stage:

 
 
SRC4192 asynchronous sample rate converter"

 
 
Wolfson WM8741 DAC chip:

 
 

 
Special attention was paid to the power supply, using a custom Plitron toroid with Schottky rectifiers and separate windings for digital and analog. The DAC chip itself gets quad voltage regulators, with 16 more spread out across the device. A total of 22 Nichicon FG capacitors in 2200uF flavor add up to nearly 50,000uF of capacitance - which is more in line with an amplifier than a DAC. SPDIF signals are received by a Wolfson WM8805 which features their patented "elastic buffer" for additional jitter reduction. Upsampling is done by a Texas Instruments SRC4192 - when not enabled, that chip gets bypassed, which is theoretically a good thing when dealing with a high quality USB signal and/or material which is already hi-res from the start. Overall the design is very ambitious, with attention paid to every little detail and no compromises to be found. 
 
 

 
 
 

 
 
 
 
You might notice the choice of 5 digital filters, which is common for the higher end Wolfson chips. Questyle says they started with the internal filters and made some improvements of their own for better performance. Interestingly, playing material in 44.1kHz or 48kHz gives a different set of filter options compared to playing hi-res music. With 88.2kHz and above the filter selection looks like the stock Wolfson set - FIR brickwall, IIR apodizing, FIR apodizing, IIR soft-knee, and FIR soft-knee. Playing 48kHz material or below, the brickwall and linear-phase soft-knee options get swapped out for linear-phase and minimum-phase half-band filters. Which is a good thing as far as I'm concerned - the traditional brickwall filter almost always takes last place in my experience, with the soft-knee filters usually not far behind. It's nice to have options, though personally I have a favorite which I use most of the time. 
 
 
 
 
Quick boot sequence, just takes a few seconds:

 
 
 

 
 
 

 
 
Upsampling disengaged:

 
 
Toslink actually accepts 192kHz which is often claimed but rarely true:

 
 
IIR Apodising, my favorite digital filter:

 
 
Upsampling engaged:

 
 
Note how upsampling is always a direct multiple of the original sample rate:

 
 
Different filter:

 
 
True DSD playback does no use any digital filtering:

 
 
   

 
 
EQUIPMENT
I used a wide variety of gear during this evaluation. The base of the system is an APC S15 power conditioner, with Cabledyne Silver Reference cables all around. I fed the CAS192D over USB with a MacBook Pro running Audirvana, or a Dell Inspiron 17R with JRiver Media Center. I also spun discs with a YBA Design WM202 and later an Arcam FMJ CD37. I sometimes used the Audiophilleo 1 with PurePower as a reference for testing the USB implementation. Amps included the CMA800R (obviously) in single or dual mono configuration, as well as the Auralic Taurus mkII, the Yulong Sabre A28, and the Icon Audio HP8 mkII. For electrostatic goodness I used the KingSound M-10 or a custom built hot-rodded KGSShv. Headphones included the KingSound H3, the Stax SR-007mk2, Sennheiser HD800, Audeze LCD-2 and LCD-3, beerdynamic T1, HiFiMAN HE-6 and HE-500, Alpha Dogs, Noble Kaiser 10, JH13pro FreqPhase, and the Unique Melody Merlin. 
 
 
 
T1:

 
 
Aurender X100L:

 
 
YBA WD202:
 
 
Questyle stack with dual mono CMA800R amps:

 
 
KingSound electrostatic setup:

 
 
Yulong A28 balanced amp:
 
 
Questyle stack, note the Stax O2mkII hiding in the background (KGSShv not shown):

 
 
LCD-3:
 

 
 
LISTENING
My initial focus was to pair the CAS192D with the CMA800R. I started with just one and later added another for dual mono mode. The result, whether using one or two of the amps, was nothing short of a brilliant match. The CMA800R is a highly resolving amp that will quickly point out flaws in a signal chain, so Questyle had to make sure their flagship DAC was up to the task. At the same time, it would be easy to overdo the detail aspect and make this combo somewhat fatiguing. Thankfully that's not the case here. 
 
No, the CAS192D is not an overly smooth DAC. It's not romantic, relaxed, or forgiving in the least. And yet, it has a sort of unforced clarity to it that allows me to enjoy it for hours without finding it too lit up. This is the sort of thing that makes me question the need for things like NOS DACs, syrupy tube output stages, or other "smoothing" techniques. If people are averse to "digital" sound, the best course of action might just be to seek "better" digital sound, rather than covering it up with a dark, rolled-off design. Once you hear all those details, all that air up top, with deeply carved images and superb localization, it's hard to go back to an amorphous blob-like presentation - compared to something like a Rega DAC ($999), Opera Consonance Orfeo ($1799), or Mojo Audio Mystique ($1949 in upgraded form), the CAS192D is decidedly more insightful yet no less easy to enjoy. In fact the Rega in particular sounds downright slow and dull in direct comparison. I suppose if we only listened to poorly recorded, overly compressed modern music then that sort of thing might be welcome. In most other instances it is definitely not. I don't mean to pick on NOS designs and I realize the Rega is not a NOS design (the Orfeo and Mystique definitely are but all have a similar sound to my ears) - but you see where I'm going with this. "Musical" sounding DACs certainly have their place but there's another approach as well, involving designs like this which are exceedingly clear but also very clean and non-fatiguing.
 
How about an example by way of comparison? I happen to have an Arcam FMJ CD37 on hand - a $2300 CD/SACD player which also uses the WM8741 (actually two of them on a differential configuration, but who's counting). This is an ideal device for comparing to the CAS192D because they aren't priced too terribly different, and yet they use the same DAC chip. Therefore, they must sound similar, right? Actually, no. Not at all. The Arcam is all about speed and articulation. When used on its own I find it to sound fairly nice if sometimes a bit overly "Hi-Fi". But when compared directly, the Arcam becomes obviously thin and brittle, with midrange and especially bass being inadequately fleshed out. The Questyle is more tonally rich and has a tactile presentation which makes the Arcam seem lean in comparison. Transients, which seem a strong point on the Arcam when used by itself, now just sound etched when viewed in light of the more fluid Questyle. In short, the CAS192D walks away from the comparison. Keep in mind the Arcam was being used as transport to feed the CAS192D so there shouldn't be any discrepancy there. I can see why someone might prefer the smoother Mojo DAC to the Arcam - complaints of "digital" sound come to mind. But I can't for the life of me imagine anyone not wanting to ditch both of those in favor of the Questyle, unless your system is really bright and needs significant taming. 
 
After trying a bunch of different amps and feeding the CAS192D with difference transports, I got a pretty good feel for how it performs in various scenarios. First off, I like it ever so slightly better from the XLR outputs. RCA is quite good too and I have no complaints when I must use them, such as with my Icon Audio SET amp or the KingSound M-10 that only has RCA inputs. But when given the choice due to an amp having both types of inputs, I'll pick XLR. 
 
As for incoming signals - that's an interesting discussion. When using a "standard" USB input (ie, a regular laptop rather than high-end music server) the USB input is just about on par with coaxial SPDIF via my YBA Design WM202. I could make coaxial take the lead by using the Audiophilleo USB to SPDIF converter, or I could make coaxial fall behind through the use of a more pedestrian source - in my case a Dune HD Max media player which was never really designed for higher-end audio. Despite a slight reduction in quality, the Dune over coaxial or optical is still very listenable - particularly when engaging the upsampling feature. As has been the case in other devices I've auditioned, the upsampling is more and more welcome as source/recording quality diminishes. So folks using redbook quality tracks or a more basic transport will likely encounter benefits, while those playing mostly hi-res material over a quality transport or USB will tend to do better with upsampling disengaged. The differences aren't massive but they do exist, making upsampling (and the ability to disable it) welcome. 
 
Back to those digital filters: As usual, I prefer the IIR Apodizing option, so much that I rarely ever use anything else. Again, the differences are not night and day but they are definitely worth messing with. Combined with the upsampling option, you can tweak the sound to best fit your system and your preferences. I did sometimes use the linear-phase half-band filter for a slightly more relaxed/forgiving sound when playing certain Redbook tracks - I believe this filter is custom made by Questyle, and I can see how it could become a favorite as well. Keep in mind that digital filters are never an extreme change from one to the next.... I've heard people say it's like getting 5 distinct DACs in one, which I don't find to be the case at all. 
 
Both the Windows and Mac machines did a fine job over USB. Mac of course needed no drivers, but it did have an issue playing tracks that use the 176.4kHz sample rate. It just wouldn't play them. Windows needed drivers installed as is usually the case with modern asynchronous USB DACs. Once installed, I could play any sample rate without a hitch. DSD? Now that's an interesting topic....
 
Questyle doesn't use the usual DoP standard for transmitting DSD in a PCM container. Instead, it stays as DSD from start to finish, a fact which Questyle contends improves the resulting sound quality. This does require some hoops be jumped through. Questyle is a "firmware strategy partner" with JRiver and thus recommends their Media Center software, which is actually required to enable DSD playback. I have mixed feelings about that.... on the one hand, JRMC is a brilliant program, and I heartily recommend it. On the other hand, this strategy limits user choice and also excludes DSD playback when using a dedicated music server from Aurender, Auraliti, etc (which otherwise work just fine with the CAS192D). I use Audirvana with my MacBook Pro and from my admittedly limited experience, JRMC on OSX is decidedly less evolved than its Windows counterpart. I'm not sure if DSD would also work on OSX and frankly I'm not interested in switching from Audirvana to find out. 
 
That said, once I actually got DSD playback functioning via JRMC and played some of my favorite test tracks..... WOW. What a stunning experience! The resulting sound, especially with a top level system such as dual CMA800R with the LCD-3 or HD800, or the KGSShv driving the O2mkII, was simply ravishing. DSD on the CAS192D has a sense of ease to it that I find very easy to enjoy, while maintaining a highly detailed sound. There's a realism to it, a sort of three dimensional presentation that goes beyond just soundstage, which makes it incredibly lifelike and immersive. This is among the best DSD playback I've ever heard.
 
Now, before you go thinking I'm some newbie to the whole DSD thing, let me explain my history. It goes back beyond the days where external DACs were king and digital downloads were common. "Back in my day", as us old curmudgeons say, I listened to SACD on a stand alone player and it was pretty darn amazing. I skipped the original Sony SCD-1 but soon joined the club with a Marantz SA-1 which was their $7k reference SACD player. I had a fairly substantial SACD collection which I've since archived to be played back on my music server. I've played them through some excellent DSD capable DACs but rarely do I hear them sound as good as with the Questyle DAC.
 
An interesting comparison - I was able to play some of my favorite SACDs on the Arcam spinner, then play those same tracks ripped to my hard drive over the Questyle. This is the first time I've ever compared the same source material in a disc versus disk comparison. While the Arcam improved considerably when playing SACD compared to standard CDs, and was actually quite enjoyable, it simply could not keep up with the Questyle which improved by an equally large amount when jumping from PCM to DSD. 
 
For PCM playback, I'd rank the CAS192D up there with my favorite DACs in the sub-$2k range. It's very competitive with the Anedio D2 and actually sounds very similar (for those of you who know my affinity for that device, you know this is a huge compliment). It competes with, but is very different from, the BMC PureDAC, and in my opinion is superior to the thrice more expensive Esoteric D-07x due to being similarly detailed but less "shouty" in the upper mids. It may be slightly better than the Matrix X-Sabre and possibly even the Yulong DA8, depending on your system and preferred sound signature. So far so good right? 
 
However, with DSD playback, the CAS192D moves to an entirely different level. It surpasses the X-Sabre and DA8 and maybe even the Chord Hugo - yes, the True DSD functionality is that good. While the Questyle isn't quite in the same league as the more expensive Auralic Vega for PCM, it definitely puts up a good fight when playing DSD material. To surpass the CAS192D I had to go all the way up to my Resonessence Labs Invicta Mirus ($5k). I was not prepared for this situation and frankly I don't quite know what to make of it - I don't believe the DoP method, as embraced by so many well-regarded engineers from EMM Labs, Playback Designs, dCS, Wavelength, MSB, etc, is flawed. I'm not sure using "Native" DSD transmission should make any sort of difference in the end. And yet, the only DAC I've experienced which operates in Native mode happens to be hugely capable with DSD playback. Coincidence? Maybe. Probably. I dunno. Whatever the case, I'm not too worried about it, and am willing to live with the slight inconvenience in setup if it gives me such great results. To be honest, DSD material remains such a small fraction of my library that the argument is trivial anyway. 
 
CONCLUSION
So, what to make of the Questyle CAS192D? At $1500 it's extremely competitive - among the best in its class, and probably the best when it comes to DSD. On the flip side, it omits volume control and headphone amplification which are commonly found in competitors, and requires a very specific setup to utilize its DSD capabilities. So it's not the perfect DAC for everyone, but nonetheless makes a very compelling case for itself on the basis of pure sound quality. 
 
I imagine Questyle will continue to be primarily known for their headphone amplification. But the CAS192D shows them to be very capable in other areas as well. Is it right for you? I can't say definitively, but I'd absolutely recommend it over popular competition from Mytek or Burson. Yes, it's that good. If this sort of device might fit your needs I highly recommend you giving it a try.
 
 
 
 
Company Info
 
North America:
 
Questyle Audio North America. 
Attn: Mr. Bruce Ball

Add: 8825 Urbana Ave. Arleta, California, 91331 USA

Tel: 323-834-9678

Email: bruce.ball@questyleaudio.com


 
Everywhere else:
 
Questyle Audio Technology Co.Ltd.  Attn: Alden Zhao 
Add: Room 801, Block B Jialin Highrise, Shennan Road 2001, Futian District, Shenzhen, China 

Tel: +86-755-82835670

Email: alden.zhao@questyleaudio.com


 

 
 
 
 
Around these parts, there's not much that needs to be said about Yulong Audio. Quite a few HeadFiers have experienced the neutral D100 series, the warmth of the A18 and D18 models, and of course the DA8 which is just a masterpiece in my opinion. Yet if you browse over to some other audio forums, you might find that Yulong remains virtually unknown. The brand is spreading, but nowhere are they as prominent as right here at HeadFi. Lucky us - Yulong makes some killer gear at reasonable prices.
 
Under the microscope today is the latest headphone amplifier, dubbed A28. Yulong has a history of catering to headphone enthusiasts - all but a few of the prior designs have had some form of headphone amplification on board. What we haven't yet seen is a true balanced amp. Until now. 
 
The flagship A18 remains the most expensive model in the Yulong lineup. It does feature a 3-pin XLR output but, like HiFiMAN's EF-6, the XLR is merely for convenience, making it easier to deal with headphones which already have that kind of termination. The internal designs are not truly balanced. Which, I might add, doesn't necessarily make either of those amps inferior. On the contrary: both are quite good in their own ways. Still, Yulong has several fully balanced DACs on the market now, so it made sense to release a matching headphone amp with a true balanced design.
 
DESIGN
The A28 ($599) is clearly an extension of the DA8 DAC. They use a very similar enclosure available in silver or black, and even have the same unique footer system in place. The A28 stacks beautifully on top of the DA8 (or vice versa) but is a very close match to any other Yulong source gear as well. So feel free to drive it with a D100, D100 mkII, or D18, and you'll still have a nice looking stack, complete with balanced connectivity. 
 
 

 
 
The rear is ultra-simple: IEC cable connection with voltage selection, RCA input, and XLR input. That's it. Like I said - simple! A small switch handles selection between the two inputs, which again is not the most convenient design in the world. We saw this on the A18 and I made the same complaint there. It wouldn't be so bad if the switch was off to the side in a more prominent spot, but in reality it sits squarely in between the RCA jacks. If you have RCA cables connected (and I assume that to be the case if you need to use the switch) then it is rather difficult to reach behind the enclosure and access. Especially if you have it in an audio rack like I do. The upside? It helps the front panel stay nice and organized. 
 
 
 

 
The A28 can handle just about any connection you throw at it. There's a 4-pin XLR output as well as a pair of 3-pin XLR combo jacks. Each of these can accept a 1/4" jack - one labeled "high" (direct output, less than 10 ohm output impedance) and the other "low" (with resistor for protecting sensitive headphones, 100 ohm output impedance). This broad array of jacks means the A28 will work with pretty much any headphone out there, balanced or single-ended, though it won't be ideal in some cases due to impedance interactions.
 
Power output is impressive: balanced mode gives 2500mW per channel into 32 ohm loads, 1300mW into 150 ohms, 700mW into 300 ohms, and 400mW into 600 ohms. Single ended operation gives roughly 1/3 those numbers, making it still reasonably powerful. Why more power in balanced mode? This is common for balanced amps, and I sometimes receive questions asking why this is the case. It's simple really - the device is based around a pair of OPA2604 opamps driving a "diamond" buffer constructed of MJE243/253 transistors. There are 16 transistors total in the A28 - 8 per channel when running balanced mode, or 4 per channel for each of the two single ended outputs. Using the "high" 1/4" jack, for example, actually uses just a single OPA2604 (which itself is a 2 channel opamp) and 8 transistors total. A friend could be using the "low" jack simultaneously, which makes use of the other half of the amp. Make sense? This is the reason why balanced amps such as this or the Firestone Audio Bobby or the Violectric V181 really demand to be used in balanced mode.... using SE mode just wastes a lot of their potential. Also note that when using the RCA inputs instead of XLR, an OPA1632 converts the signal to balanced. There is a small penalty paid here, but definitely not as significant as using just half of the amp via the SE output. So if you must deviate from a fully balanced setup, better to have a balanced headphone and a non-balanced source than the other way around. 
 
 

 
Build quality is typical Yulong - see any of their other reviews for more on that, or just check out my pictures. Not much more to say on the topic. As always, North American customers are encouraged to purchase from Grant Fidelity. They offer excellent support both pre and post-sale, and were instrumental in translating my questions to the designer of this amp. Their price is on par or lower than the various (and potentially not authorized) sellers I see on eBay, so you might as well buy from a trusted source. 
 
 
 
THE SYSTEM
Since I'm a big fan of Yulong gear, I was able to pair the A28 with various products from the same family. I used their P18 power conditioner fed by their D230 AC cable as the basis for this system (all other cabling was Cabledyne Reference). For transports I used a YBA Design WM202 CD player, an Auraliti PK90 with NuForce LPS1 power supply, or later an Aurender X100L music server, with or without the Audiophilleo 1/PurePower. DACs were mostly Yulong - the D100 mkII, the D18, and the DA8 - but I also used the Questyle CAS192 and BMC PureDAC. For headphones, a wide variety of styles including HD800, HD650, T1, LCD-2, LCD-XC, TH-900, HE-500, HE-6, Alpha Dogs, Noble 4C and 8C, JH13FP, and ES5. All headphones have balanced cables - most using a 4-pin XLR but some with dual 3-pin style - with the exception of the T1 which is stock. I have single-ended cables for most headphones too, so I could switch them out to compare balanced performance versus SE.
 
 

Dual 3-pin XLR from CablePro
 

4-pin XLR from Toxic Cables
 
 

Stock 1/4" cable from Audeze
 
 

 
 
 

HE-6 and Thunderpants
 
 

LCD-XC
 
 
 

Way too much gear to list - I see TH-900, Alpha Dogs, HE-500, Spider Moonlight,Westone
ES5, amps from Questyle and Auralic, and a Chord Hugo
 

 
As you can see, I have a lot of gear to write about at the moment, so I was able to burn the A28 in for a long time before I got to it. I didn't bother to keep track, but it must have had several hundred hours (at least) before I gave it a serious listen. Burn-in believers, rest assured: that was not an issue here. 
 
LISTENING
Yulong (the designer himself) is interesting because he doesn't always stick with the same "house sound". Look at his prior amp designs and you'll see the A100 on the more analytical side of the spectrum, and A18 on the opposing end with a smooth, musical presentation. The opportunity was there to make a generally neutral amp while still keeping the highly technical performance Yulong is known for. I'd say the A28 achieves just that.
 
I'll cut right to that chase and say that if you intend to use this amp, you really should have a balanced system as your goal. Yes, it does have RCA inputs and single-ended outputs, and they don't sound terrible. But they also don't showcase the full capabilities of this amp. The RCA input is less of an offender - it's merely a small step down in performance compared to XLR. But still.... the best way to hear this amp is fully balanced from start to finish. 
 
Having established that, I tended to stick with Yulong DACs to feed XLR outputs to the A28. The amp was very capable of revealing differences between the D100, the D18, and the DA8. I started with the D100 (mkII, since my original D100 is out on long term loan to a friend) and got very satisfying results. This combo was nimble and articulate, with a nicely defined soundstage and tight imaging. While not the most expansive thing I've ever heard, the accuracy more than made up for it. This was a tight, punchy sounding combo that had nice bass weight to the HD800 (balanced with Toxic Cables Scorpion cable) and yet didn't overdo it with the LCD-2 (stock balanced cable). I heard just the slightest bit of grain, which was only really noticeable in comparison to something like my AURALiC Taurus - which of course is much more expensive. It didn't have the highest resolution I'd ever heard but was nonetheless satisfying considering the investment for DAC and amp. Overall I'd say the A28 was more than capable of showing off everything the D100 had to offer.
 
I then moved up to the more expensive D18. Now this was a whole new level of performance. As much as I enjoyed the D100, it was something of a lightweight compared to the rich, creamy presentation of its upscale sibling. Talk about open and spacious! The D18 remains one of the better DACs I've heard in that aspect, and the balanced A28 didn't hold it back one bit. I normally use the D18 with the matching A18 amp, so it was interesting to hear the difference with A28 in the mix. It was colder, but not cold in absolute terms. It was nearly as open sounding, with soundstage reigned in just a touch. Low frequency extension was similarly weighty but more dialed back compared to the A18, which is a rather warm amp compared to most. But the biggest difference came in terms of treble presentation: A28 had significantly more sparkle and air up top, while A18 was more rounded and smooth. Each presentation had its place - I preferred the A28 with my Alpha Dogs (stock balanced cable) and HE-400 (balanced with Toxic Cables Hybrid), while A18 was superior with HD800 and quite a bit better with the Beyer T1 (stock single-ended cable, which definitely caused a disadvantage to the A28). The A28 seemed to have a lower noisefloor, making it better with sensitive low impedance cans of all types. It's still not completely silent with IEMs - my Noble 8C (Toxic Cables Silver Poison balanced) was definitely listenable, and actually made for a better fit than with A18, but I still prefer it with other amps - the noisefloor is still not ideal, nor is the output impedance. And then there's the HE-6 - HiFiMAN's fussy flagship does a passable job with A18 but really comes alive with the A28 (again with the Toxic Cables Hybrid). I do love the creamy smoothness with A18, but the A28 just does a better job with more headroom, realistic air up top, and a more open sound. This is probably the most affordable amp I've yet heard that makes the HE-6 sound really good. This is also an extreme example of the single-ended discrepancy compared to balanced; the HE-6 does a complete 180 when used from the 1/4" jack, sounding thoroughly uninteresting and flat. Good thing HiFiMAN gives us a balanced cable right from the factory.
 
Ascending the heights of Yulong's source offerings, I tried the DA8, and took yet another step up in performance. This time I heard all of the low end weighty goodness I had with D18, plus more airy treble and more speed. This was still no wispy, ethereal sounding system, and I'd call it slight tilted towards warmth.... but overall pretty neutral. I was really impressed by the upgrade compared to the integrated amp in the DA8 - which is already very high quality. The A28 is best via XLR, and the DA8 amp is 1/4" only, so the comparison is not completely fair. But in general the result was "similar yet better". Better extension on the top end. Definitely more sparkle and clarity. Richer midrange fullness, but not to the point of becoming overly thick. And bass extension? Yep, deeper and more authoritative. The A28 digs deeper into the recording to extract spacial cues and subtle details the DA8 amp can sometimes miss. But here's the thing - some headphones don't show much of a difference. For example, if I had some model from the AKG K7xx series, I'd rather just run it straight from the DA8. The A28 just doesn't add much in that case, and is definitely not worth the extra money. HiFiMAN's HE-400 is similar - the DA8 integrated amp already has plenty of power for that relatively sensitive planar, and the added cost to go balanced is somewhat prohibitive. However, with an LCD-2, or HE-500, or most Sennheisers, the difference is obvious and rather welcome. I'll reiterate what I said in my review of the DA8 - it has an excellent integrated amp section; one of the best I've heard. And yet, it can't keep pace with the A28 when used with some headphones. The DA8/A28 combo comes in at just a touch under $2k and I really think it's an amazing setup for that (relatively) down to earth price point. I've certainly heard my share of more expensive combos that didn't impress me anywhere near as much.
 
I got good results by using non-Yulong DACs, despite the "stack" no longer matching. The A28 seems transparent enough to pass along whatever traits the DAC may have. So the Questyle CAS192 excelled at clarity and focus, while the BMC PureDAC was all about tonal accuracy. I can imagine a few instances where the A28 wouldn't make a good match with a particular source. The first, more obvious scenario - a DAC or CD player with no balanced outputs. Again, the RCA connection is not horrible by any means, yet it doesn't take full advantage of the amp. So running the A28 straight from the RCA outs of my YBA Design WM202, which I normally consider to be a great sounding CD player, sounded reasonably good but not amazing - no fault of the YBA. The other situation would be if the user needs a smoother amp to calm down the treble in their system. A brighter DAC, and a headphone like HD700 or Grado, would not make for a good system with the A28 in my opinion. In those cases, A18 is far more desirable. 
 
Speaking of poor matches... some headphones just don't work very well here. Recall the output impedance is a bit under 10 ohms on the 1/4" jack labelled "high", and double that for either balanced output (4-pin XLR and dual 3-pin XLR are the same). So we can logically infer we need headphones under 80 ohms for SE mode or under 160 ohms for balanced. And remember, this only applies to dynamic drivers, as planar magnetic models don't care so much about output impedance. So what brands does that eliminate from our list of candidates? Grado. Audio Technica. Ultrasone. Sony. And probably a few more that I'm forgetting at the moment. Also most IEMs are off the table. What's left? Planars from Audeze, HiFiMAN, Fostex (including various mods such as Mr. Speakers), and soon Oppo. Most Sennheisers. Many beyerdynamic models. Is that enough for you? Is it wrong for an amp to be somewhat selective in its pairings, while being extremely good when a proper match is found? Only you can decide.
 
 
COMPARISONS
The Yulong A28 is a brilliant amplifier when used in the right context. Unfortunately for them (but good for us!) it has some excellent competition in the same price range. A few years ago, this was not the case. In my recent experience there are three very good amps worth comparing to A28: The Lake People G109 (in the $600-700 range based on options), the NuForce HAP-100 ($595), and the Firestone Audio Bobby (MSRP is higher but often discounted to $500-600). 
 
Picking a winner in this field isn't so easy. No single amp takes the lead in every category. Specifically, they each have their own unique focus in both sound signature and headphone pairing. So we need to break it down a little to find which works best for a given situation.
 
The Yulong and Firestone are fully balanced, and sound best when used that way. The Lake People and NuForce are single ended only, though the former can be had with XLR inputs for a few extra bucks. So based on system matching (or planning for the future) you might eliminate half the field based on the balanced aspect alone. 
 
To briefly compare the strengths and character of each amp: 
 
The Firestone Bobby is similar to the Yulong in a lot of ways. It uses quad OPA604 opamps (which is the mono version of the OPA2604 using by Yulong) driving a transistor buffer. It has similar output impedance, and using SE mode will only engage half the amp. In direct comparison (balanced of course), the Yulong is slightly warmer, while the Bobby has a leaner, more airy presentation. Both have great soundstage but the Bobby edges out the A28 by a hair. In exchange, the A28 has more authority in terms of low-end impact. In the end, it breaks down as follows - both models are very good with planar models, but A28 is better, and is the only one capable of handling the HE-6 (have I mentioned it does quite well with that model?). Both models are also very good with the Sennheiser HD600/650 as well as the HD800, with the Firestone being a little better overall (especially with HD800, which seems counter-intuitive based on signature, but it just works). Neither model is ideal with IEMs or low impedance dynamic headphones. Personally, the A28 works for me with the headphones I happen to use more often, and the slightly warmer tilt is welcome more often than not. Your preferences could just as easily go the other direction though.
 
Compared to the NuForce HAP-100, the Yulong is more resolving and hits harder, but has a less "exciting" sound. HAP-100 seems to emphasize midbass and upper mids, in a sort of smiley-face fun EQ situation. When it works, it works marvelously - look no further than HD800 for proof of that fact. The HAP-100 pairs spectacularly well with that particular headphone. It's not necessarily the most neutral you'll ever hear the HD800 sound - maybe it was never intended to sound like this the first place. Regardless, it's really enjoyable. The NuForce also works nicely for the lower impedance dynamic models like Audio Technica and Denon. The A28 won't do those so well, but is easily superior with planar models, where the NuForce is merely "capable" at best. So, again, both models have their specialties, and your preferences will determine which is the best match for you.
 
Lastly, the Lake People G109. I actually have the G109P with the XLR inputs, which allows me to properly compare them using the same exact outputs from my DAC. The Lake People is very similar to the more expensive Violectric V100 (though not an exact match) but using a less fancy enclosure to keep costs down. It has the distinction in this field of being absolutely compatible with every headphone out there, from sensitive IEMs to the HE-6 and everything in between. It does use an internal jumper for gain adjustment, which is less convenient than the external switches on the Violectric models. I tend to leave mine on a low setting because it works well with most headphones, but if I was using it as a dedicated HE-6 amp I'd go for a higher gain. Still, it's far more versatile than any of these other three amps. Output impedance is less than 1 ohm so no impedance related issues. The G109 is a universally good performer and an easy recommendation for someone who hasn't settled on their favorite headphones yet. Having said that - the A28 seems to perform better in certain instances. I can't say if this is due to the balanced aspect, or just the sound signature. Both amps are very powerful and both do their best into lower impedance loads - G109 does 2300mW into 50 ohms, while A28 does 2500mW into 32 ohms. Which means both are ideal for planar magnetic headphones. In fact, these amps are more similar than different, and at times I had trouble telling them apart. I definitely prefer the G109P with IEMs and low impedance cans like the Fostex TH-900. I +think+ I prefer G109P with my HE-500. And I generally like it a bit more with my Sennheisers and beyerdynamic models. The rest of my planars - HE-400, HE-6, Alpha Dogs, LCD-XC, and LCD-2, seem a little better with the balanced A28. It tends to bring out more "bite" from the somewhat dark LCD-2 while at the same time avoiding edginess with the HE-6. It seems like we could generally call the G109 darker/more musical, and the A28 more neutral/higher resolution, but then they both go and defy those descriptions at times, with certain headphones. So I give up trying to characterize them any further and just put it like this: for me, these two are just about tied for my top recommendation in this space, with the NuForce and Firestone amps trailing behind (and roughly tied for second place). Which is an impressive achievement for Yulong given the high quality of this field.
 
Other worthy competitors may exist, but I either haven't heard them or haven't spent enough time to really draw a useful conclusion. I definitely like the A28 more than the Schiit Lyr, based on what I've heard so far. I suppose some combination of tubes may exist that brings the Lyr up to another level, but I've not found it yet (and I've heard it with some rather pricey tubes). The Mjolnir is not one that I've heard enough times to decide on.... I sort of liked it, but then again I found it somewhat edgy and aggressive. It's very exciting for the short term but I'm not sure how long I would enjoy it. That's about all I can think of for the moment - I don't care for the Burson Soloist (any of them), nor do I find the Woo WA6 particularly amazing for the price as an all around performer (though it sure does sound nice with a few specific headphones). I could go on, but realistically I think the reader will know by now if the A28 might be their sort of amp - so I'll stop here. 
 
CONCLUSION
Lots of words written above, and I'm sorry if this ended up as somewhat long-winded. That's the price we pay for having so many good options appear in this class within the last year or so. The quick and dirty version: Yulong has yet another exceptional performer in their stable, capable of matching the best in the category. Neutral with just a hint of warmth, the A28 sounds utterly ravishing when used with the right headphones. Downsides? Yep, there are a few, as expected for the price. Balanced inputs are recommended, balanced output is downright mandatory. And not every headphone will be a good match. If you can work within those parameters the A28 will reward you with some of the best performance available this side of a four figure price tag. 

 

 
Remember Edifier? The company that now owns Stax? I recently covered their e10 Exclaim desktop speakers and found them rather impressive for just $99. While making a nice budget speaker is certainly noteworthy, part of that equation involves most other speakers in that price being rather poor. Edifier is able to stand out merely by not being terrible. Doing a higher-end design is another matter altogether - in the $300-600 range, competition is fierce, and quality options are plentiful. Could Edifier climb the ladder into this hotly contested segment?
 
Their entry in this field is the Spinnaker, which I refer to as a "system" because of its unique traits. The thing that immediately jumps out about this system is the external design. The shape is rather.... unconventional. To say the least. Standing over 16 inches tall, each speaker has a shape I can only describe as "horn-like". There's a joke in there somewhere. Covering the majority of the enclosure is a "sock" type material in the grand tradition of speakers like Vandersteen or the classic DCM Timewindow. The enclosure itself is made from a double walled polymer, with a nice touch of metal for the stability "lip" on the lower-rear section. Take a look at the pictures: one could describe the Spinnaker as futuristic, bold, striking, adventurous. Or just plain goofy. I'm not sure I'd disagree with any of those. What I will commit to is that Edifier did not choose a boring design here. Judging by their other models this seems to be a theme of theirs. 
 
Rather than being chosen purely for shock value, it seems the tall, tapered design actually makes sense here. As a three-way, tri-amplified design, each driver has different space and placement requirements, which the cone-like shape seems to accommodate. Occupying the bottom portion and taking up more than half the total enclosure volume, the 4 inch down-firing woofer is fed by a dedicated amp good for 25 watts RMS. Above that is a 2.75 inch midrange, and finally a 1 inch silk-dome tweeter up top, each getting 10 watts RMS from separate amplifiers. A 6-channel DSP system manages the whole operation, digital crossovers and all. It's really a surprising amount of technology in a $349 desktop speaker system. 
 
 

 
 
The fun doesn't stop there, as Edifier has outfitted the Spinnaker with a fairly broad array of connectivity options. For physical connections, there's a 1/8" analog input, a Toslink digital input, and then a 1/8" output for adding an external subwoofer. The Spinnaker is also capable of accepting wireless signals via A2DP Bluetooth connection. This is a rather unique collection of choices, about which I have somewhat mixed feelings. I would have much rather seen a USB input rather than Tosklink, because computers these days seem to be moving away from built-in optical. USB is a guarantee for every PC or Mac. Also, the 1/8" jack is a bit of an odd choice. I had assumed it was meant to quickly pair with smartphones or tablets. But the location (underneath the "master" right speaker) is not at all ideal for that sort of thing - it seems Edifier may have just not had the physical space for an RCA connection. Lastly, the choice of A2DP Bluetooth rather than AirPlay actually makes a lot of sense to me, except I would have liked to see Edifier use the aptX codec for better performance. So overall it's something of a mixed bag for me.
 
 

 
Continuing the theme of "unique", the remote control is definitely unusual. It's a little wireless dome that sits on your desk (or wherever you want it) and communicates with the speakers via RF - no line of sight needed. The main body spins left or right for volume control, and the button on top does different things when pressed once, or held down, or used while rotating the knob. These actions result in skipping tracks, cycling inputs, muting, or even power on/off. The volume control part is pretty straight forward, with the other aspects being somewhat less intuitive. It worked fine once I got the hang of it but I did wish for a more traditional remote at times - especially when accidentally brushing up against the device, and therefore adjusting volume when I hadn't intended to. Still, I love it that Edifier tried something bold and different here - it might have been easier to do the typical credit-card-sized plastic remote, which just wouldn't fit with the character of this unique product. While I have some reservations about the concept, I must admit the execution is well done - battery life is substantial (I recharged via USB every few weeks), range is good, and the solid metal construction feels great in the hand. Overall a fine job by Edifier. 
 
 

 
 
Just as the Spinnaker system looks different from any other desktop speaker I've encountered, so too does it deviate in terms of connectivity. This meant a wide array of messing about to experience what each option is capable of. Right from the start I figured I should grab a baseline by using the optical input - surely this would demonstrate the best Edifier had to offer. My desktop PC currently uses the Asus Xonar Essence STX sound card which provides a Toslink output, so with that connected I was off to the races. This type of output is not as common as it once was, so those interested in the Spinnaker should verify their system before just assuming. For example - the Macbook Pro does have it (through the headphone jack combo port) but the MacBook Air series does not. As is often the case with optical, this implementation tops out at 24-bit/ 96kHz.
 
Setting the Spinnakers in my usual desktop configuration - roughly 3.5 feet apart and slightly toed in - I noticed something I liked right off the bat: the height and the angle of the cabinet result in just about perfect placement. The midrange and high frequency drivers fire directly towards your ears for an ideal experience without the need of a stand. I've harped on this point in the past but it really can't be overstated, and Edifier seems to be on the same page - their $99 e10 Exclaim (link) speakers had a similar setup. 
 
I fired up some of the usual test material - Britten: War Requiem, Jazz at the Pawn Shop, Lateralus, Blue Train, and a little Norah Jones just to cover the "overplayed audiophile songstress" category. The Spinnaker system impressed right off the bat with very nice clarity and definition. The overall presentation seemed balanced, for the most part, with a bit of extra "excitement" compared to my Serene Audio Talismans http://www.innerfidelity.com/content/serene-audio-talisman-computer-speaker which I use for a reference. Low frequency extension was pleasing, with reasonably solid depth and convincing impact considering the size of the speakers. I can imagine some people wanting a subwoofer to flesh out the lows for a true full-range experience, but for the most part I don't really find it necessary - you'd be spending at least a few hundred dollars more for a decent sub, and for that total outlay you'd have a huge number of great speakers to choose from. But that's just me... I've always preferred to spread my cash between two speakers rather than three. Still, it's nice to have the option, especially if your main interest is watching movies, where the extra sub-bass is definitely more important.
 
Pleased with what I had experienced thus far, I used the system for several weeks in this same configuration. Over that time I made a discovery that I had not initially noticed. Essentially, I found that I absolutely loved the Spinnaker in smaller doses. If I wanted to jam for 30 minutes, I'd be extremely satisfied. The sound was bold, engaging, and vivid, to the point where it made my Talismans seem kind of dry and uneventful. I loved the top end sparkle, and the drivers seemed very well integrated - a concern I initially had due to the three-way design. 
 
The flip side of this energetic performance? I grew a bit tired of it in the long term. An hour of classical was usually fine, as was more laid back electro like Kraftwerk or Emancipator. But give me an hour of more aggressive jazz (The Bad Plus), prog metal (Mastodon), or electronic stuff (Crystal Castles) and I'm pretty much spent. The Spinnaker doesn't do any one thing terribly wrong; it's just that the presentation lends itself to fatigue with certain music. Focusing on the positive once more, the good thing about this dynamic sound is that it sounds great at lower levels, reducing the need to crank volume and thus more quickly kill ears. 
 
I mentioned the superb driver integrated earlier, and I think that aspect really helps imaging. While the Spinnaker is not the most expansive sounding speaker in terms of soundstage size, what's there is nicely open and well defined. With 6 drivers, 6 channels of amplification, on-board DSP, and crossovers to tie it all together, there's a lot going on behind the scenes here; and it seems Edifier has done a great job considering the price. 
 
I did notice what seemed to be cabinet resonance at higher volumes. These things sound great at low to mid levels, which is a good thing because I don't think they do so well when the volume is cranked. So while they do great in a near-field situation, I probably wouldn't recommend them as traditional speakers to fill a larger room with sound. They struggle with higher output, specifically in the bass region, so it's best to avoid 90+dB levels. I really think they are more appropriate to use in nearfield situations anyway, where this problem would almost become a non-issue.
 
I can't really think of a headphone that exactly matches the Spinnaker presentation. My Lear LCM-2b custom IEMs are probably the closest, if we remove most of the bass under 60Hz or so. But those aren't well known so the comparison doesn't help much. In terms of more commonly known headphones - I'm hearing a mix of Denon D2000 and some Grado if that makes any sense. Probably closer to the Denon but with less bass. Sorry for the imperfect comparison but there it is.
 
 

 
Later I switched to the analog input and was very impressed when it didn't sound much different from optical. Considering the extra analog to digital conversion taking place, this is a nice accomplishment. Yes, there's a small dip in clarity, and if you listen hard you'll probably spot it. The difference is not large though, and I'd be comfortable running it this way all the time if that's the only connection I could muster. 
 
Unfortunately I can't say the same about the Bluetooth option. The connection was robust and never gave me trouble on a technical level (good range, too) but sound quality took a considerable dive. It sounded as if the speakers had been wrapped up in a thin blanket or something - sound came through, but it was muffled and indistinct compared to what I heard earlier. This is not surprising considering the rather pedestrian Bluetooth implementation on board... I've been impressed with aptX solutions such as the Wren Sound speaker and Voxoa headphones, but this is clearly not on the same level. Then again, since I don't find the Spinnaker all that suitable for 2-channel, non-desktop use, the Bluetooth thing probably doesn't matter so much anyway. Honestly, when used in a desktop scenario, Bluetooth adds very little to the equation. So for me, personally, it's not a big loss. 
 
 
CONCLUSION
The Edifier Spinnaker is not a speaker I would have anticipated enjoying. Based on looks, I would have thought it was a marketing experiment gone wrong. And yet, in actual use, the darn thing is a very solid performer. Its quirky appearance actually serve a purpose, and the resulting sound is impressive - especially in smaller doses. 
 
If Edifier could get some market saturation, get these things set up on display like Bose so often does, they'd be sure to sell loads of them. The energetic presentation grabs you from the first note and refuses to let go. A somewhat flawed analogy would be walking into Costco and seeing some huge 70+ inch high-end LCD panel on display. They have some colorful Pixar Blu-Ray showing and everything is cranked up to the max - contrast, brightness, all sorts of processing. You've seen this movie in the theater and you know it didn't quite look like this, but you still find yourself mesmerized. Would you want to see this all the time? Probably not. Is it nonetheless impressive at that moment? Sure is. The Spinnaker system doesn't take it quite that far, but the general sentiment is the same. If you can handle the unusual looks, and don't require extreme volumes, the Spinnaker should definitely be on your list of "things to try". 
 

When a new company called Voxoa contacted me about reviewing their new Bluetooth headphones, I was this close to turning them down. I had no idea who Voxoa was but the very idea of a wireless headphone seemed rather unnecessary to me. When I listen to headphones, I'm usually sitting right next to my audio rack. Or maybe I'm using my iPad or an Android tablet - which is either in my hands or propped up a few feet in front of me. None of these situations involve me needing freedom from a cable. But it's been a while since I tried a wireless headphone so I figured I might see how things have evolved in recent years; I agreed to check out the Voxoa product.
 
The last few wireless headphones I tried were both from Sennheiser. I tried the RS120 which was a budget model, and it sounded terrible to my ears. Very compressed and dull. Later I spent some time with the RS180 which was actually pretty decent. I remember thinking to myself "these are nice enough, but I'd probably just get a wired headphone with extension cable and call it a day". I never got to try the RS220 which, if reports are to be believed, sounds as good as an HD600 (give or take). Since the RS220 sells for a rather high price, I don't think I'll ever try it unless once happens to fall into my lap somehow.
 
The Voxoa HD wireless headphones are a bit different than the Sennheisers I've tried. They don't use a base station. They don't accept Toslink or coaxial inputs like the RS220, nor do they handle analog RCA signals like the RS120. They use neither infrared nor RF technology. Instead, the Voxoa HD communicates via Bluetooth. Yes, Bluetooth. It's not just for weirdos who appear to be having an argument with themselves at the grocery store (Bluetooth earpiece or not, people should not be having these conversations in public!). Voxoa's technology is very up to date - they use Bluetooth 4.0 and apt-X technology for the best performance obtainable using an IEEE 802.15.1 signal, aka Bluetooth which is a lot more catchy.
 
The basics of the design: supraaural (on the ears) design with soft pleather earpads, rectangular cups, nicely adjustable plastic (but sturdy) frame, and a several buttons used for volume control and track skipping (which works well). There's a mic on board for hands-free calling. The looks of these things definitely reminds me of several other models I've seen from Monster, among other brands. But it's just a basic design and there's only so much one can do to differentiate themselves. By using the rectangular cup design Voxoa has automatically invoked similarities to any other model using rectangular cups. That said, the aesthetic is not bad at all. I got the black version which is clean and understated, but not boring. White is also available and it seems a little more flashy, if you're into that sort of thing.
 
Interesting options: the Voxoa HD comes with a rather short cable, with which it can be used like a "normal" headphone. The battery life for wireless mode is listed as 16 hours and my experience says that is roughly accurate. But if one ran out of juice, the cable is there as a backup. It's a good idea which doesn't really work out in practice, as I'll explain later.
 
Another interesting feature is the NFC capability. NFC stands for Near Field Communication and is becoming more common on newer cell phones. There's an area on the upper side of the Voxoa HD marked with "NFC" letters - simply touch your phone to that point and the two become paired. No digging through a Bluetooth settings menu required. This worked well for several phones I tried. I can't say it's a must-have feature, since the manual process is not all that difficult... and really, how often will you be pairing new devices with the headset? Still, it's a welcome feature that helps the Voxoa HD feel very current. I get the impression NFC will be a standard on lots of devices as things move forward so Voxoa is ahead of the game. 
 
I found the headset to fit my head very well. It's not the most robust design out there, nor the most plush/comfortable, but it seems in line with other headphones in the sub-$200 price category. I love the free swiveling of the cups in all directions - I can't imagine someone not being able to find a good fit with these. My only potential complaint is one I've had with many other headphones in the past: the main contact point sits on the crown of the head, and that pressure can become tiresome for some people. I myself am not particularly bothered by this, but I know some people are. If Ultrasone headphones bother you in this way then you might want to steer clear of these. 
 
As far as actually listening, I find the Voxoa HD surprisingly enjoyable. Let's not pretend - for $150 you aren't getting an absolute high-end experience. That's true of standard wired headphones, so how would a wireless model be any different? That said, I've heard traditional wired headphones costing up to $200 which don't match the Voxoa HD in sound quality, so I think it does well for the $150 asking price.
 
The sonic signature is definitely what I'd call "fun". That means big, bold bass, somewhat tipped up treble, and a midrange that takes something of a back seat to those frequency extremes. I don't think it's too recessed as a general rule, though some recordings may bring that out just a bit. Keeping in mind the sound one tends to get in this price class though, I'm not disappointed in the least. If these were regular wired headphones I'd say they were good, if not outstanding, and I'd recommend them for certain people. But that's not the case, is it? The Bluetooth aspect makes these something else entirely, and the value becomes something better than just average.
 
I enjoyed the sound with most types of music. As is usual with a somewhat V shaped signature, classical music is not a major strong point. The bass here is reasonably well controlled though so unlike some other bassy headphones, these don't sound like a mess when playing dynamic orchestral works. I did find myself taking advantage of that generous bass though - I'd gravitate towards classic hip hop like Eric B and Rakim, Wu Tang Clan, even some Brotha Lynch (which I enjoy in very small doses on occasion). Electro stuff was great as well - I played lots of it ranging from old Kraftwerk and Art of Noise to modern stuff such as Electronic Noise Controller, Marc Houle, Emancipator, Crystal Castles, and of course stalwarts like Chemical Brothers, The Prodigy, and Daft Punk. A big beat with some sparkle up top is a classic recipe for enjoyment with this type of music and the Voxoa did not disappoint. 
 
I'm surprised at how much I enjoyed jazz on these headphones. Hiromi's beautifully frenetic piano on Haze (from the album "Voice"), the smooth saxophone of Yuri Honing on his dynamic cover of Walking on the Moon (from "Star Tracks"), or Big John Patton's Roland B3 on, well, all of his albums (I recommend his Mosaic Select box set, if you can find it). Although it doesn't perform on the level of a Sennheiser HD598, which pretty much sets the standard for transparent midrange in this price class, the Voxoa is certainly not the worst I've heard. It isn't the best with vocal oriented music though, and I found myself staying away from that sort of thing more often than not. So if your tastes involve a lot of singer/songwriter type music you might not enjoy the Voxoa as much as someone else who prefers more instrumental fare, or just more pop oriented stuff. 
 
One thing I noticed is that I prefer the Voxoa HD at lower volumes than normal. Maybe it's the punchy, exciting sound signature, which allows me to feel a good amount of impact without cranking it up too loud. I consider this a good thing. The flip side is that higher volumes don't sound as good. Bass distortion creeps in at higher volumes so I'm glad the sound is good when kept lower. 
 
Now, there are some specific things I have to mention about getting the most from these things. First, the cable is a nice touch - in theory. In reality it seems like a flawed solution. Why? Because the incoming (digital) Bluetooth signal gets run through a DAC and DSP, tuning it for best performance before the speakers send it to your ears. The cable bypasses the DSP process - which makes sense, because the signal already resides in the analog domain. Still, this gives a distinct reduction in sound quality as opposed to using Bluetooth. It becomes a caricature, a gross exaggeration of an already colored sound. It goes too far and to my ears is no longer enjoyable. So, while the cable will do in a pinch, if your battery dies and you really must have sound.... it's not ideal. I also think, at least for me, there's some mental gymnastics involved. When I plug my headphones into a dedicated headphone amp, I expect a certain caliber of performance. Wireless headphones? I have very little expectations to speak of. I'm almost certain this bias is at play when I complain about wired performance - it may be different for other users. 
 
One alternative (which I have not yet had a chance to try) involves connecting a USB cable from the headset directly to your computer, effectively using the Voxoa HD as a USB DAC. My contact at Voxoa tells me this will work, though it requires a separate USB cable. Apparently the bundled charging cable will not work for data purposes. If this method truly works, then it should sound better than using the analog cable, since it won't bypass the critical DSP function. 
 
Another important aspect is the aptX connection. I have a fairly modern MacBook Air which I figured was up to the task of supporting this format. Connected easily via Bluetooth and played some music, everything sounded fine. But when I check my Bluetooth connection, under Voxoa HD, it showed "Active Codec: SBC". SBC? That's not aptX! Some quick Googling uncovered THIS thread showing this to be a common problem. The solution is to download something called Bluetooth Explorer (the link is further down in that thread). It's not a simple thing - I had to register as a developer (which I'm not) before I could get the file I needed. Once I did get it, I followed the steps which basically involve checking the box to "force use" of aptX. Initially it didn't work but after a series of resets (the MacBook and the Voxoa) it magically straightened itself out. 
 
The difference between SBC and aptX is not night and day, though I do find it noticeable with the right music. AptX seems more nuanced and layered in terms of soundstage, and especially helps enhance high frequency response. It sounds more natural and I have less issues with artificial (ie not in the recording) sibilance and harshness. The improvement applies more to complex music than simplistic material, which makes sense as we are butting up against bitrate limitations for lossy transmission. So for modern pop it's not much of an issue, while lovers of classical, jazz, and other good recordings should be sure to get aptX set up first thing. You'll be glad you did. Think of it like switching to 320k mp3 from 128k mp3. It's still not the best sound you've ever heard but as improvements go, it's significant. 
 
It can be tough with other devices to really know if aptX is being used. CSR, the company behind aptX, supposedly maintains a list of compatible devices. We can break it down by device type to see things like smartphones and tablets. I'm not so sure they keep it up to date though.... or at least not completely. The newer Samsung Galaxy S 4 models are listed but I don't see the Meizu MX models nor do I see the Wren Sound V5BT system, both of which I know to have aptX on board. For what it's worth Voxoa does make the list. A lot of phones won't specifically mention apX though - they claim Bluetooth 4.0 with A2DP but don't list aptX so in those cases I don't think we get it. But I could be wrong. This of course is not Voxoa's fault. 
 
I found range to be very good. Like anything wireless, it can vary from one situation to the next, especially when other electronics are involved. I was able to roam freely around a large room without a single interruption. Wandering into other nearby rooms seems to be more of a challenge - it worked in many instances, but not all. As a test I left my phone in the living room, walked around the corner and down the hall all the way to my bedroom, where the sound finally started cutting out. By this time there was quite a distance between the phone and me, and several walls in there too. I never expected to have free reign of the whole house though, so I'm pleased with the performance here. It clearly improves on the old Sennheiser models which seemed to have very low range. I can imagine these doing very well for someone who had a big yard and wanted to wear them out there while keeping the source on a deck or in a windowsill. Without walls getting in the way I suspect the range would be even better. 
 
In the end I think a product like this really requires some thought. When would you use it? What are you pairing it with? Is 15+ hours of battery life enough time? If the answers to these questions point you towards a wireless headphone, and you enjoy a warm/exciting signature, the Voxoa HD is a solid choice. I don't have a lot of experience with this category but I'd be shocked if the competition had anything significantly better for the price. Are these the best headphones I've ever heard? Of course not. Are they acceptably good considering the price and features? I'd say so. I look forward to seeing what else Voxoa comes up with - wireless in-ear monitors? Speakers? I see lots of possibilities. 
 
 

 

 
 
A while back I reviewed the CMA800, which was the flagship product from a brand new company called Questyle Audio Engineering. I actually screwed up and listed that review under the CMA800R heading.... I created a proper entry and migrated the original review there, and I'm now replacing this section with the proper content. Anyway, I was absolutely smitten by the CMA800's ultra-transparent presentation - it was easy to recommend for the asking price of $1,500. Since then, many others have gone down the Questyle road and  arrived at similar conclusions. The Questyle name has become rather well known in a relatively short amount of time, and for good reason: their gear is excellent.
 
Although it was their main product, Questyle has already discontinued the CMA800. Why? To launch the CMA800R which is basically an evolution of the design, tweaked for slightly improved sound quality and increased functionality. As much as I loved the original, I think the replacement is a considerable improvement. Let's discuss why.
 
Actually, before we proceed, I ask that you read my original review (in its new location HERE) if you haven't already done so. That will get you up to speed on Questyle's unique Current Mode Architecture and save me from rehashing the same info all over again. Then come back here when you've finished and we can keep going.
 
Done? Good. Now, onto the CMA800R. The "R" model looks nearly identical to the original. At first glance you might notice one or two small differences, but generally speaking it's the same enclosure with the a very similar appearance. What's new? Let's discuss, because there's more going on than you might initially notice. 
 
 
The first big one for me is the feet. It might sound petty, but I consider it worth mentioning. I gave Questyle a hard time for using pointy little "cone" feet on the CMA800 which looked great but didn't inspire confidence when stacking the amp on something. Whether it was another component (probably a DAC) or just a nice platform on your rack, dresser, or whatever you put your gear on - regardless, nobody wants to scuff up their stuff. So the pointy cones were wisely replaced by more traditional feet with soft material on bottom. Now stacking is perfectly safe, and the unit doesn't slide around so much when plugging in a headphone. Added bonus - Questyle throws in the old cone style feet as well, which can easily be installed if the user so desires. Use them if you dare.... it's nice to have options. 
 
 

 
The next big thing is the preamp output on the rear panel. It's an RCA output, and it passes along whatever incoming signal is active at the moment. So theoretically one could use the CMA800R as a simple preamp, with two sources (one XLR, one RCA) selectable from the front panel switch. This is handy for complex systems (like mine) where you'd like to integrate several different amps all from the same DAC. Or, it could be used for driving a pair of active monitors in a desktop setup. Personally I think every amp that doesn't have a significant size or budget limitation should have this feature, and I'm pleased to see it here. 
 
 

 
Hmmmm, what else? How about a minor change in the faceplate side "fins" for an angled look? How about a volume knob that protrudes a little more, making it easier to handle? These are welcome but really don't scream "new model name" by any means. There's got to be something more.... and there is. Questyle tweaked some internal things, nothing major, but it nets an improvement - THD is down, power is up, and the overall sound a very slightly improved. None of this is drastic by any means though. I'm talking 5% at most. It's the sort of thing where most companies would not even bother to call it "Mk2" or anything of that sort. 
 
 

 
 
 
 

 
But wait - what's that new output jack on the front, next to the volume knob? Is that a single 3-pin XLR connection? Why on earth would you need a 3-pin connection? Balanced operation requires either a 4-pin XLR or dual 3-pin XLRs - did Questyle mess up here? And how about that lone 3-pin XLR input on the rear? What's going on here?
 
 

 
 
Now we're getting to the heart of this upgrade. The CMA800R is an exceptional choice when used as a traditional amp. However, it also has the capability of running with two units in a fully balanced, dual mono configuration. This brings large increases in current delivery and voltage swing (obviously) as well as completely isolating each channel which can only be a good thing. Essentially, all the benefits touted by makers of monoblock speaker amps are at play here, but this time the minimum investment starts with just one amp - add another down the road when you can afford it. Those 3-pin XLR ins and outs suddenly make more sense, don't they? 
 
Questyle was one of the first to bring separate chassis dual mono operation to the table. Woo Audio, to my knowledge, was the first to advertise it with their ultra-expensive WA-234 ($15,900/pair) which handles both speakers and headphones - but I'm not sure we could actually buy the thing until a while later. By that time Questyle had launched their monoblocks in their home market, followed by a USA launch shortly thereafter. Both companies had claimed to be the "first" to do it, and it's close enough to where both claims seem reasonably legitimate as far as I can tell. I doubt either of them knew what the other was working on, and both actually launched (as in, I could purchase one here in the USA) within a very similar time frame. NuForce later joined the party with their affordable HA-200 ($698/pair) which doesn't really aim to compete with the others, but does have similarities to the Questyle on a conceptual level in that we get to start with just one and later add another if we want - the WA-234 only operates in dual mono. 
 
The Questyle CMA800R sells for $1,499 meaning a pair of them clocks in just shy of $3,000. That's significantly more than the NuForce but waaaaay less than the Woo. It's also something of a "standard" price range for a top of the line headphone amp. In this field we find the Bakoon HPA-21 ($3,000), DNA Stratus ($2,700), HeadAmp GS-X mk2 ($2,800), Woo Audio WA5-LE ($2,750), a few different amps from Eddie Current, and maybe we'll top out at the Apex Teton ($5,000). There are more expensive amps out there - the previously mentioned Woo WA-234 and the Apex Pinnacle ($10,000) come to mind - but that's a rather significant jump even for someone who can afford a $3,000 or $4,000 amp. 
 
So how does the CMA800R distinguish itself in this field? First off, I need to once again acknowledge the excellence of running a single CMA800R. At $1,500 this may very well be all the amp you need - see my review of the CMA800 and add a few percentage points of clarity. It's among the most transparent sounding amps I've ever heard, and when paired with the HD800 it may very well be the most clean, clear, resolving amp available. The price then becomes something of a bargain if that fits your sonic sensibilities. 
 
However, when comparing a lone CMA800R to something like an AURALiC Taurus mkII, I hear the single CMA800R falling behind a little when using difficult to drive planar magnetic headphones. Specifically the HifiMAN HE-6, but also others to some extent. The Taurus has significantly more power on tap and just seems to drive all planars with authority that the Questyle can't quite match. The CMA800R still does a very respectable job - it's actually among my favorite amps for the LCD-2 and Thunderpants, and still does better than most with the HE-6. It's just that direct comparisons to the Taurus or Violectric V200 show it could benefit from increased horsepower. The dual mono setup might be just the ticket here. 
 
Before discussing the sound in depth, I should cover the connection process. It's not complex but there's some stuff in there worth mentioning. First, you absolutely need an XLR output from your DAC or CD player. Balanced outputs are becoming more common these days so I don't really consider this an issue - even if you can't afford a higher-end DAC (like Questyle's own CAS192D for example), a number of reasonably inexpensive balanced models now exist (Yulong D200, Schiit Gungnir, and Parasound Zdac to name a few) that sound quite nice and don't break the bank. 
 
Next, you'll need a balanced cable for your headphones. You can use a cable that terminates in dual 3-pin XLR, or you can do like I do: headphone cables terminate in 4-pin XLR, and then an adapter is used to convert that to the dual 3-pin format. I prefer the 4-pin XLR style and I see it slowly becoming the standard.... but obviously Questyle needed separate jacks for each amp, so the dual 3-pin jacks make total sense here. I use a really nice adapter from the CablePro Freedom series, and I'm very pleased with it. Any reasonable cable firm should be able to make one of these for you without charging an arm and a leg.
 
 

 
 

 
 

 

 
 
Lastly, and this is sort of optional: you might want to have volume control on your DAC. The CMA800R has the same high gain as the original CMA800, which means it gets rather loud, rather quickly. There's not a whole lot of travel on the volume knob to dial it in just so. Using the dual mono setup, each channel needs to be matched by hand - so you can see how the somewhat touchy controls would be a little inconvenient. Amps with independent controls for each channel are not common but there have been a few out there over the years -  specifically the DarkVoice 337, La Figaro 339, HeadRoom Blockhead, as well as the HeadAmp KGSS electrostatic amp. Anyone who has used one of these knows it's a situation easily lived with, yet also sort of annoying at times. If you tend to switch headphones often, or listen to a contrast of music (ie a quiet jazz album followed by a modern pop album back to back), matching the channels each time can become tedious. Doubly so when gain is on the high side as it is here. If you stick with the same headphone and listen to similar music most of the time then you can set them up once and leave them alone for the most part. But that won't work for me. My solution is to set them at a fairly high level, then ease back the volume from my source. My Resonessence Labs Invicta Mirus can attenuate up to 35dB on 16-bit material with no loss of resolution (mathematically or subjectively). Plenty of other DACs do a good or even great job of this as well so I see no problem using it. Questyle's own CAS192D doesn't have variable output so in that case I just make do with the separate volume knobs, though I suppose I could use a preamp in the chain if I really felt the need. The SPL Volume2 seems to fit the bill and at $449 it isn't obscenely priced - that's probably the direction I'd go if I wanted the full Questyle stack but didn't like individual volume knobs. Either that or wait for Questyle to finish their preamp - it's currently in the works but I don't know the release date. It will most certainly cost more than the SPL but will be a more upscale design and will have the same form factor as the CMA800R. 
 
 
Equipment
I've been using the CMA800R for a while now, so I'm very familiar with it. When the second CMA800R arrived I threw it right into my reference system - Aurender X100L music server feeding an Audiophilleo 1 with the PurePower battery option, out to the Resonessence Labs Invicta Mirus DAC, then the dual CMA800R monoblocks driving a variety of headphones. Power conditioning done by an APC S15, all cables were Cabledyne Reference Silver except for the CablePro XLR adapter and the various headphone cables from Toxic Cables, Charleston Cable Company, and Effect Audio depending on the headphone. I later tried a variety of other DACs including the Questyle CAS192D, the B.M.C. PureDAC, the Esoteric D-07x, and the Calyx Femto, just to see how the amps responded to different sources. I'll discuss that later.
 
 

 
 

 
 

 
 

 
 

 
 
 
 

 
 
Listening
The first headphone up was the Sennheiser HD800, which is where the "800" in CMA800R comes from. This is the headphone Questyle used as the main reference when designing this amp and it really shows. A single CMA800R is already my favorite amp for this particular headphone. How would two amps improve that situation? My first impression was..... slight disappointment. I wasn't hearing any drastic changes - no veil lifted, no clouds parting, no added details in my favorite songs that I never knew existed. Then again, it was already on such a high level with one amp that it would probably be unrealistic to expect a major change. So I settled in and tried a wide variety of excellent recordings until I got more of a handle on the differences. 
 
What I eventually determined was that the dual mono, fully balanced setup was primarily more expansive, as well as more accurate in terms of imaging. This was already a very spacious and precise system but the monoblock configuration made it that much more believable. Frankly, I'm not sure I've heard a headphone system with such a well developed sense of space. Granted, the $5,000 Invicta Mirus surely has a large part to play here, as does the Audiophilleo, and the Aurender, and every other little detail in the system. But I later noticed an improvement in this area no matter what DAC I was using (assuming it was of reasonably high caliber) - going from a single amp to dual always resulted in a more lifelike spacial presentation. As much as I adore my electrostatic rig - using a supercharged KGSShv amp to drive the Stax SR-007 - the dual mono CMA800R plus HD800 has it beat hands down in this particular area. 
 
Obviously this isn't going to matter when you play your favorite Beastie Boys album... you'll need to use material that contains this information in the first place, in order to hear this improvement in spacial detail retrieval. I had great results from many of the currently "popular" audiophile labels such as Reference Recordings, Mapleshade, Blue Coast, MA Recordings, and 2L. Also lesser known (at least that's my perception) but no less excellent, Opus 3 and Proprius have some really enjoyable stuff in their respective catalogs... though I'm pretty much done listening to Jazz at the Pawnshop for the millionth time. With material from these excellent labels, I was able to hear deep into the mix, discerning the characteristics of the room and where each performer was located within the boundaries of that space. Pretty amazing stuff. I also had fun with the classics like Mercury, RCA, and Blue Note, and although these were not as well carved out, they still contained a good sense of order within the recording space. And I was occasionally surprised to hear information buried in a JVC XRCD that I haven't played in a while. Redbook CD? Yeah, absolutely still viable as a format when done right. 
 
This continued from other well known labels such as Chesky and MFSL to more obscure ones like Audiofon. Using the Aurender X100L server made it simple to browse through my multiple terabyte library to find all this stuff. The general rule of thumb was this: dual mono mode sounded discernibly superior with any recordings that had suitably high aspirations. The best of the best, for the most part, were more clearly fleshed out on the dual mono stack. Good but not quite great recordings, without the inherent ultra-realistic sense of space, still showed some improved clarity and dynamic gusto - not a massive change, but enough to appreciate. In the end I'd say the HD800 was most certainly improved in this configuration, but it also placed requirements on the listening material which may not mesh with some users. If you're not interested in exploring new labels and possibly music that you wouldn't ordinarily try, it may not be worth the expense. Again, this is not really a shortcoming of the dual mono setup, but rather due to the extraordinary sound a single amp already achieves with the HD800.
 
Next I tried the most difficult headphones I own, the HiFiMAN HE-6. The single CMA800R did a respectable job with these but still fell short of the "magic" I know them to be capable of when used with a more powerful amp. Running monoblock mode obviously increases the current and voltage delivery, so I was curious to hear how it would play out. I was not disappointed. With several full Watts on tap and voltage swing through the roof, this was a potent combo indeed. I got a sense of control and grip that was a lot less prominent with the single amp, helping the HE-6 avoid that upper midrange sharpness it can sometimes display. Bass impact was significantly improved too - I could now do justice to all my favorite Maggotron tracks, though as usual the "bass music" gimmick wears off after about 10 minutes. The improvement on the HE-6 was less subtle than it was on the mighty Sennheisers - I think most people would be able to appreciate it right away, even when playing something as pedestrian as Jimmy Eat World or Swedish House Mafia. There's a significant increase in layering, but the main thing is a more well-rounded, organic tone. On a single amp there's a definitely focus on quickness and leading edges, which are top notch thanks to the current mode architecture producing vanishingly low distortion measurements. Adding another amp rounds out the decay, making for improved transients and more realistic timbre. Despite HiFiMAN moving on to their new i-series, the HE-6 remains a top performer when paired with good enough amplification, and the dual CMA800R is up there with the best I've heard for these headphones.
 
 

 
 

 
After the huge improvement of the HiFiMAN flagship, I figured it was time to try the Audeze LCD-3. The big Audeze, being more sensitive than the HE-6, doesn't really need bulldozer levels of torque to drive it properly. But it isn't afraid to show any weakness in the chain either. The single CMA800R already does a good job here. Perhaps not on the same level as it does with HD800, but still competitive with other amps I have in the four-figure price range. So I didn't have massive expectations.... I figured it would be more like the HD800 than the HE-6. I was way wrong.
 
The LCD-3, for the first time in my experience, sounded like it was actually worth the price increase over the LCD-2. I've always said that I enjoyed the 3 and appreciate the accomplishment Audeze has made, but wouldn't recommend shelling out double to get the relatively modest improvement it brings compared to the 2. With the fully balanced dual mono Questyle system in play, I started to eat my words. The sound was simply more "alive" for lack of a better term. All the usual cliches about vocalists being in the room with me, or hearing subtle harmonies I hadn't noticed prior? Sure, those work, but they don't really get to the heart of what I'm trying to express. A good example comes from the old Sheffield Lab drum test disc, of all things. The CMA800R sounded great by itself - dynamic, expressive, full bodied - pretty much as good as I'd like it to sound. Or so I thought. Switching to dual mono, I got an immediate and obvious increase in snare drum "snap". Cymbals had more convincing decay. Bass drum thumps were not only more impactful but also had superior texture. In short, everything just sounded more like a real drum set, which is probably something only a drummer would understand. Or at least someone who listens to a lot a live drum performances. Same deal with piano - I don't really play but a family member does, and as such I'm accustomed to hearing it from the other room on a regular basis. I don't care how amazing my 2-channel rig might be at any given moment, I've never had a setup that would trick me into thinking it was the real piano instead of a recording, when heard from down the hallway. The analogy falls apart when we talk about a headphone system, but still - playing Hiromi's Haze off her album Voice (I used an SACD rip from the rare Japanese release, but a standard CD version is also excellent), the dual mono setup comes significantly closer to fooling my brain, where the single amp "merely" sounds like an excellent reproduction, nothing more. Not that anyone in my house ever plays piano like that, but you get the idea. 
 
Is it the extra voltage swing? The higher current delivery? The improved crosstalk due to physical separation? The beefier power supply by virtue of doubling the regulation and capacitor reserves? Don't know, don't really care. All I can say is - this combo rocks. I tried it with the LCD-XC, Alpha Dogs, HD650, and a Grado PS-500, with each one showing various levels of improvement. The planar magnetic models seem to love soaking up the extra juice, while the dynamic designs seem more concerned with the improved separation and transient response. It did make me wish every headphone came standard with balanced termination or at least removable cables - I had a Fostex TH900, beyerdynamic T1, and Thunderpants which were all hardwired as 1/4" termination, meaning I wasn't able to give them a spin. I imagine I would have heard improvements there too but I could be wrong.
 
 
 
Let's recap for a minute - difficult to drive headphones show the biggest improvement here, with LCD-3 and HE-6 each getting a significant boost. The HD800, already a champ with a single amplifier, gets a more subtle upgrade - which may or may not be worth the trouble depending on your listening preferences. It really comes down to system matching and what you hope to achieve from adding another CMA800R to the mix. 
 
Speaking of system matching.... let's talk DACs for a second. As I said, the best results I got was from my Resonessence Labs Invicta Mirus. The dual mono CMA800R setup is extremely resolving and really lets the Invicta Mirus soar to incredible heights. Unfortunately not every source is as capable. With the amps being brutally revealing of every flaw, I really needed the right DAC for the job. On the plus side, the right DAC was not always the most expensive. 
 
I actually didn't really care for the $7,000 Calyx Femto in this system. It reminded me a lot of the Esoteric D-07x which I also struggle to love. They both have plenty of zip and zing, but not enough "meat" to the presentation. Everything is so fast and lean and in your face - "look at me I'm a detail!!!!!" It's great for a demo but for long term? Music doesn't really sound like that in my experience. I prefer a more natural and organic presentation, though not rolled off or dark either. Thus, I did far better with the less expensive B.M.C. PureDAC which has a wonderfully rich, full bodied tone, while remaining incredibly accurate. Questyle's CAS192D was also excellent (as you'd expect for matching components) with a neutral but definitely not boring presentation that ticked most of the boxes (the exception being lack of volume control). I also had great results with the Yulong DA8 and even the inexpensive Yulong D200 which goes for well under a grand. All in all I'd say there's plenty of choice for driving the dual mono setup, but you gotta stay away from anything too lit up (unless that's your preference, then by all means go for it). 
 
 
 
CONCLUSION
Is the dual mono CMA800R setup worth it? That's a question I get rather often. I can't really say definitively that it will be worth it for everyone, but for me it seems like a no brainer if the budget allows. I won't promise night and day improvements across the board and in some cases (especially HD800) the improvement is conditional - only certain types of listeners will reap the benefits. In other cases it's more drastic and fairly obvious to my ears, taking the solid performance of a single amp and lifting it up to world class. DAC matching takes a little care but isn't terribly difficult so there really isn't an excuse not to go for it. 
 
Overall I'd say Questyle has done it again. When I reviewed the original CMA800, I mentioned how a few other brands use some variation of current-mode operation, but Questyle has their own unique interpretation which sets them apart. Likewise, a few other brands have separate, dual mono, fully balanced headphone amps on the market, but none do it the same way as Questyle - the Woo uses tubes and has a price tag in the stratosphere, while the solid state NuForce is a relatively affordable solution not meant to compete in the big leagues. 
 
The Questyle CMA800R, while not cheap, is already an excellent amp when used alone. Adding another turns it into a world class powerhouse that can challenge most anything on the market. The fact that we get to incrementally upgrade rather than buying all at once makes it that much sweeter. I heartily recommend it assuming you have the proper source and headphones to take full advantage. 
 
 
 
Company Info
 
North America:
 
Questyle Audio North America. 
Attn: Mr. Bruce Ball

Add: 8825 Urbana Ave. Arleta, California, 91331 USA

Tel: 323-834-9678

Email: bruce.ball@questyleaudio.com


 
Everywhere else:
 
Questyle Audio Technology Co.Ltd.  Attn: Alden Zhao 
Add: Room 801, Block B Jialin Highrise, Shennan Road 2001, Futian District, Shenzhen, China 

Tel: +86-755-82835670

Email: alden.zhao@questyleaudio.com

See my full review HERE. In summary, this is a well rounded, high performance amp that really offers a lot for the price. It's neutral, clear, and balanced - literally speaking and in terms of sound. Not sure why it isn't more well known. 

4C
The Noble 4C ($699) is a quad driver design in the same vein as the Heir 4.A, which means a three way crossover, dual low frequency drivers, and separate drivers for mids and highs. I still have my 4.A and still enjoy the heck out of it, as a mostly neutral, but slightly forgiving model with very broad appeal. But I gotta say the Noble 4C is probably better for most people. Those who remember how much I enjoyed the 4.A will know how big of a statement this is.
 
Why? You may recall some complaint about the 4.A having a rather potent "dip" in the response centered around 4kHz. This was measured in the 4.Ai which was the universal model, and I have to say I did hear that fairly prominently. I never thought it was the deal breaker that some made it out to be - in fact that was not even my biggest complaint about that particular model. My custom 4.A doesn't have nearly as obvious of a dip - if it's there, it's very slight. It could be my ears glossing it over but I'm inclined to think otherwise since I did hear it in the universal model. Regardless, Wizard tweaked things in the Noble 4C to account for this 4kHz dip, so depending on your perspective the frequency response will now be flat, or (comparatively) slightly boosted in my case. 
 
A quick word about aesthetics. As usual, Wizard has done an amazing job. My 4C is done in a great dark purple color, very slightly translucent but hard to see inside due to the color depth. It's got some type of gold threads or something in the faceplate, very very cool looking and unique. The effect is better in real life, and my amateur hour photography simply does not do it justice. 
 
Despite not having any complaints about my Heir 4.A, I really do enjoy the Noble variant a bit more. Note that we aren't talking about a massive difference - they are both cut from the same cloth, but the focus is somewhat shifted here. The new sound is something I might describe as a junior version of the JH13 FreqPhase - mostly neutral with just a bit of added energy or excitement, making the experience rather engaging as a whole. The Noble 4C has very nice bass performance that lies somewhere between true neutral and the slightly more robust impact found in the JH13. The more expensive JH13 seems to have more sub-bass impact which is welcome, but the 4C isn't too far behind. I'm not sure what Wizard did to tweak the bass, or if perhaps it's a byproduct of the general tuning on this new model, but it seems to draw slightly more attention to itself this time around. Not a lot mind you - this still isn't a bass monster. It has more impact and perceived extension than the Etymotic ER4 models though, and more than the Heir audio Tzar350 if anyone is familiar with that unique sounding model. Compared to the Heir 4.A I feel like the Noble 4C is very slightly more textured and robust in the lows. For all I know this could come down to standard variation between drivers, but that's how I hear it.
 
The main change from 4.A to 4C seems to be detail. Where the 4.A was slightly on the forgiving side at times, the 4C is more ravishingly detailed. By that I mean it comes across as having more sparkle, more "bite", in those upper registers. Just like the JH13, this results in a more exciting, involving presentation which really grabs your attention and refuses to let go. Note that this is not to be confused with "brightness", which is not a word I'd choose to describe the 4C at all. I never get a sense of things sounding shrill, and rarely do I get sibilance that isn't already there in the track. Much like the JH13, the 4C prefers good recordings but is not ultra-picky about it. I can still enjoy average quality stuff such as the New Amsterdams, Jimmy Eat World, Murder by Death, and that sort of thing. Yet when I play some really well done music - Reference Recordings, JVC XRCD releases, MFSL - the Noble 4C really scales well. Truly poor recordings - Death Magnetic and Californication and the like - are practically unlistenable experiences. Which is unfortunate, but pretty much how it should be given a transparent headphone. So if you tend to listen to a lot of newer, highly compressed, radio-friendly stuff, these may not be a good choice at all... though I can't imagine you'd buy this nice of a CIEM if that was all you intended to play.
 
Speaking of scaling well, the 4C is excellent for home use with high end equipment. Not that I don't enjoy it on the go, mind you, but with a highly resolving IEM such as this, better gear pays dividends. I start with something simple - iPad, Sansa Clip+, and the result is reasonably enjoyable. Nothing amazing, but pretty good. Switch to an older (and better sounding) iPod 5.5g and running an LOD to various portable amps, the Noble 4C responds accordingly. Go all the way up to the HiFi ET MA9 (an obscure but killer sounding high-end DAP from China) or the iHiFi 960 feeding digital out to a Leckerton UHA-6S mkII, and the 4C definitely reaches a higher level. At this stage the 4C is notably superior to all the budget oriented customs in my collection. Yes, it's more expensive than the $400 or $500 dual/triple driver models, but it's worth it if you have the gear to take full advantage.
 
At home, the 4C just continues to impress. The 30 ohm impedance and moderate sensitivity (for an IEM) mean it doesn't require much power at all. The only real limitations here are the same as most other IEMs - a low output impedance is essential, and some powerful amps have too much gain or noise. Nothing unique about the 4C in this regard. I use it straight from my Anedio D2 or Resonessence Invicta with fantastic results. The Yulong D100 mkII does a great job, especially for a reasonably affordable device. My Violectric V200 is also amazing - despite being a very powerful amp, the noise floor is practically non-existent, especially with the pre-gain switches turned down low. The other more potent (and mostly Class A) amps in my collection don't do as well though. Yulong's A18, the Auralic Taurus mkII, and the Questyle CMA800 all have moderate hash or hiss thanks to their higher gain, so none of them is really ideal. My favorite though, in terms of real word scenario and matching what a typical consumer would probably use, is the Resonessence Labs Concero HP. Straight from a MacBook Air over USB, this brilliant little DAC/amp has loads of resolution and plenty of musicality to make the 4C a highly satisfying listen. At under $1600 for the whole shebang (not including the Mac of course) this combo approaches the best I've heard for a "reasonable" price. A very impressive combo that I can recommend highly enough. 
 
So is the Noble 4C always better than the Heir 4.A in every circumstance? No, I wouldn't go that far. The Heir is still a great CIEM and has its own charm. Those who might prefer a less energetic presentation might do well to stick with the original model. As I mentioned, the Noble 4C is something like a junior version of the JH13 FP, while the Heir 4.A is very similar to the Frogbeats C4 if that comparison helps anyone. They both have merit. That being said, I prefer the Noble model in most cases. 
 

 

 

 

 

 

 
 

 
8C
The Heir Audio 8.A was (and is) one of my all time favorite CIEMs. A flagship design with 8 drivers per side. A pile of 5 star reviews at HeadFi. A coveted spot on the Wall of Fame at InnerFidelity. How do you top something like that? The answer comes in the form of the Noble 8C ($1299). Wizard describes it as having a slight increase in high frequency response, while still maintaining the buttery smooth mids and textured lows of the original Heir 8.A model. I could probably stop right here because that pretty much nails it.
 
Much (digital) ink has been spilled about the Heir 8.A and the rich, creamy sound it produces. It remains one of my all time favorites of the headphone land, regardless of style or price. And yet here comes the Noble 8C to make it even better. How is that possible? Well, I didn't really think the 8.A needed any tweaking at all. Once you wrapped your brain around the bold low frequency presentation, ultra analog sounding mids, and highs controlled with a vice-grip, the 8.A was really something special. Yet I did hear some feedback from a few users hoping for just a tad more presence with vocals, and just a hint of added air or sparkle up top. It wasn't uncommon for folks to send me messages asking about aftermarket cables to tease out that last bit of performance. I never really had complaints in that area but I could see their point - and I did find myself gravitating towards aftermarket cables such as the Toxic Cables Silver Poison or the 93spec from 93 East (both of which are silver based). So when Wizard told me about his changes made in the Noble 8C I was very curious to hear how it played out.
 
In a nutshell, I'd say the Heir 8.A is analogous to the original Audeze LCD-2, while the Noble 8C is like the newer LCD-2 rev 2. That means less "shelved" top end, more extension, and consequently a more balanced presentation overall. But don't get the wrong idea - the 8C remains rich and creamy, with massive bass response that takes no guff from any other basshead IEM. Even the Unique Melody Merlin, with its dynamic driver dedicated to lows, does not manage to pound harder than the Noble 8C. Keep in mind I'm talking quality bass here. Sure, you can find models out there with more rolled off treble, sloppy mids, and huge pounding bass, which give the impression of having bigger bass just my virtue of their sound signature. But as far as actual quality lows, I can't think of anything that beats the 8C. Even the Unique Melody Platform Pure 6 system with the bass boost feature does not pull it off - it sounds great in standard form but is less bassy than the 8C, and adding the bass boost makes the quality drop considerably. 
 
So, the bass is astonishing. But the 8.A already had that. What's new here? This time around the presentation is more balanced, less tilted towards being warm and smooth. It's still smooth but the top end has more bite, more air, more presence from the vocal range on up. This means singers take a more forward stance in the mix, and things like brass or guitar also come through more prominently. It still has that huge soundstage which is among the most expansive I've yet heard from a custom in-ear monitor. And it remains somewhat forgiving compared to the 4C or the JH13 or the Unique Melody models. In that aspect the 8C is more like the Westone ES5 - which happens to be one of my absolute favorite CIEMs. They both sound absolutely killer with high-quality tracks, but even modest recordings come off really well thanks to their somewhat forgiving nature and smoothness up top. It's a delicate balance - how to capture fine detail but not push it in your face and highlight every flaw in the process? If the Etymotic house sound is on one end of the spectrum, I'd place the Heir 8.A on the other, with the Westone ES5 and Noble 8C straddling the middle. 
 
Let's talk about that comparison a bit more, because I think it's a good one. The ES5, an extremely good CIEM, doesn't have as much bass kick as the 8C. It's got excellent extension but I feel the 8C has better texture down there. It does more to create the illusion of actual, visceral bass impact. The 8C, while seeming to have a slight reduction in midbass warmth compared to the Heir 8.A, still has more midbass presence than the ES5. Not too much  midbass in my opinion, but just enough to make recordings sound slightly "bigger" and more authoritative than it otherwise might. Midrange is very close between these two - the ES5 seems very slightly more midrange focused, but not necessarily more forward. I think it's really a byproduct of the superior bass texture, the midbass, and the top end extension of the 8C, where the ES5 has less of those which causes the midrange to really stand out. I hear a little more sparkle with the 8C but the two are still quite similar in their overall choice of tuning. That said, I do think the Noble is the overall superior CIEM - it's maybe a little more colored, but neither one is really aiming for true neutrality in the first place. So it's like the 8C beats the ES5 at its own game. Which is extremely impressive in my book.
 
Once again, the Noble is not a better choice than the Heir version, 100% of the time. I love what the Wizard did with the 8.A and I'd be a fool if I tried to downplay its brilliance now. Remember when the Audeze LCD-2 came out and reviewers kept saying "Now this is how real treble should sound - most other headphones are overdoing it!" Eventually some people came out and admitted they found the LCD-2 a bit dark, at least with some music and on some systems. When the revised model came out, reviewers had a hard time justifying the tweaks which brought out more treble extension. If the original was "right" then was this new version wrong? It's a tough thing when you paint yourself into a corner like that. For my part, I do like the LCD-2 rev 2 more, though I appreciate the original and can understand why it remains a favorite for some users. Same deal with the Heir 8.A - the Noble 8C is the more complete package, the more balanced design overall, without losing the magic of the original. But some people may still prefer the warmer, smoother Heir 8.A sound, and there's nothing wrong with that. For me, personally, I gotta say the 8C is my new favorite CIEM. Period. I like it better, overall, than my ES5, my JH13 FP, my UM Merlin, my Heir 8.A and even my Heir 6.A Limited Edition. That doesn't mean these don't each have their area where they shine brighter, and each one is an extremely good CIEM in its own right. But the 8C just hits the spot for these ears. I've got an HD800 sitting here, an LCD-2 (the newest version), a Stax SR-007,  beyerdynamic T1, Smeggy Thunderpants, HiFiMAN HE500 and HE-6, the list goes on.... and guess what I've been reaching for first these days? The Noble 8C is just wildly impressive on so many levels. Is it just the new toy syndrome? To some degree it might be, but since I've "gone pro" writing for InnerFidelity (and now Part Time Audiophile as well) I've pretty much gotten over the whole concept of liking stuff when it first shows up. If anything, I treat each new arrival as something of a chore - it's gotta really be good for the price to justify any listening time around here, and the 8C has been getting quite a bit. That should tell you something.  
 
And we can't forget the looks. Yikes, these things are amazing! Mine have what Wizard calls "Mystic Swirl" which is really hard to describe. Opaque, vaguely purplish with swirly accents, the closest analogy I can think of is an expensive bowling ball. And the faceplate has what appears to be red foil inlays in the shape of the Noble crown logo. I'm certain I am butchering this description so please look at my pics, as humble as they are, for a better idea. They are truly stunning. 
 
 

 

 

 

 

 

 
 
Other Stuff
Let's talk about a few other things. First off, options. You can go to the Noble Audio websiteand see the various options, from the entry level 3C at $450 to the Kaiser 10 at $1599 which has - you guessed it - 10 drivers per side. I'm curious about that beast but I'm so happy with the 8C, I really can't imagine things being any better. Maybe I'll find out some day. Anyway, selecting a model lets one see about pricing for various cosmetic options. The Wizard Design option is $300 and I have yet to hear a disappointing tale from letting the Wizard take the reigns. Or, just pick the wood faceplate or carbon fiber or whatever else you want and design it yourself. Interestingly, if you select the Kaiser 10 or 8C and start adding options, the price doesn't change. That's because those models come with everything included, short of Wizard Design, inlays, or rush orders. So while $1299 or $1599 is certainly a lot of money, it's more reasonable than you might initially think. It's not hard to start with a $950 5C and push the price up close to the $1299 8C once some options are added. At that point it probably makes sense to go 8C since the options are already part of the price. Pretty clever right?
 
You may have noticed something else when navigating - the Universal section isn't quite ready yet, but click on the Custom section and what pops up? A choice between acrylic and silicone designs. Yes, for the first time (that I know of) Wizard is doing silicone. There are three models - triple driver, quad, and 5 driver flagship, all with silicone shells. It appears Wizard is using a layer of acrylic for the faceplate which enables far more customization than usual. The body itself has to be "clear" (which, for silicone IEMs, is not the same type of "clear" as their acrylic counterparts), but the faceplate can have carbon fiber or wood or engraved art. It's not quite the same level of customization options as the acrylic line, but it's better than any other brand I've seen. Good stuff.
 
As you can see in the pics, I used a wide variety of gear to test these CIEMs. From portable use to home use, I've got enough gear to choke a mule, and the Noble stuff seemed to do well across the board. My comparison setup for the Heir versus Noble standoff was the Resonessence Labs Invicta, a high-end DAC which features a builtin dual headphone amp section. Both CIEMs can be used at once, with independent volume trim (which ended up not being necessary), and I even used identical Magnus 1 cables to keep things fair. There's not quite any way to quickly A/B CIEMs since the removal/insertion takes a few seconds, but this is about the best way I can think of to do it. When I'm not doing comparisons, I sometimes run the 8C with in balanced mode. Driven by both headphone amp sections via a special Charleston Cable Company 8-wire adapter, fed to a balanced Toxic Cables Silver Widow, this is truly a reference level setup. Especially when I use the built in SD card playback system to play DSD files. Yummy.
 

 

 

 

 

 

 
Final Thoughts
But enough about my system - the focus here is on Noble Audio. I want to congratulate the Wizard for bouncing back from what must have been a tough ride. I was skeptical as to how he might improve his already excellent designs, but I have to admit - he has outdone himself once again. With a strong supporting cast, a co-owner in the USA who can handle logistics, and universal models coming down the pike soon, it's hard not to get excited about this new company. Other reviews should be coming in today as well and if they are anything like mine, this is going to be huge. Congrats Wizard and company!

I've had the Anedio D2 since it first came out a while back. It replaced my D1 which was a breakthrough product in my humble opinion - staggeringly good for the $1230 asking price. The D1, and later the D2, routinely came out on top when compared to other DACs in the $2,000 to $4,000 range. This is no hyperbole - I can list about a dozen such competitors which I feel are not as good (and I believe I have listed them around here numerous times). 
 
The D2 replaced the D1 and in the process added a bunch of "wishlist" items - balanced outputs, an improved headphone section with "normal" and "high" gain selections, and XMOS-based asynchronous 24/192 USB. At the time, pricing went up by $250 to $1470. But recently Anedio dropped the D2 down to $1249 which is only $19 more than the D1. It's a steal of a deal in my opinion.
 
I've discussed the D2 so much around here that I don't even know where to start. To summarize, I find it supremely accurate, clear, and resolving, but unlike Currawong I don't find it overly bright. But I'll admit it probably isn't a good match for those seeking a laid back, smooth presentation. That said, a somewhat relaxed amp could always be used in the chain (maybe a nice tube amp) if that's the desired flavor.
 
Have I mentioned the headphone amp section? Wow, it's really good! It can drive HD800 very well, with precision and accuracy normally found exclusively in (expensive) stand alone amps. It might not seem like much at first listen, but over time one begins to appreciate the neutrality and resolution, along with the absolute pitch black background. The amp remains my first choice for using high-end custom IEMs. And it works very well with LCD-2 and HD800 as well. Not ideal for the beyerdynamic T1 though, which I feel does benefit from some coloration to tame the top end response. Still, as an all in one solution, it doesn't get much better than this. 
 
Weak points? Well, the enclosure is nice enough, but not as extravagant as the original D1. Also the headphone output doesn't mute the line-outs, so that could be troublesome. The D2 came out before the DSD rage started, so it doesn't have those capabilities. These are minor complaints but maybe worth noting just in case.
 
Comparisons? For the longest time I felt the D2 was the absolute best sub-$2k unit out there, bar none. Time flies and this segment moves quickly, so finally there are a few others which compete - though nothing blows the D2 away. The Yulong DA8 is really special, as is the Matrix X-Sabre, both using the same ES9018 DAC and offering their own distinct presentations. Both of these newer units have DSD support and both are excellent for their asking prices, but neither convincingly beats the Anedio. They are different, but not better. 
 
In sum, the Anedio D2 remains a very compelling choice. With the price being lowered and availability being less of an issue, I definitely recommend the D2 to anyone who values neutrality and accuracy above all. 

 

 
 
[size=small]A few years back I reviewed an interesting little integrated amp called the Lead Audio LA-200. I quite liked it at the time, and looking back I'd say it was somewhat ahead of its time. No ordinary integrated, the LA-200 featured digital inputs and a PWM output scheme, meaning no traditional D/A conversion step was required. Sound familiar? It should, because that sort of thing is popping up more often lately - see NuForce DDA-100, or the M2 and C 390DD units from NAD. When all was said and done I thought the LA-200 was an excellent design and I really looked forward to seeing (and hearing) more from Lead Audio. The designer, Soren Mac Larsen, has extensive history at Danish audio firm Copland, and had some interesting ideas for future products. [/size]
[size=small]  [/size]
[size=small] Fast forward a few years, and Lead Audio doesn't seem to have brought much else to the market. They released an LA-120 compact DAC/headphone amp, which had several variations including a battery power option. But the LA-120 was apparently a limited release and I haven't heard any customer feedback on it. Rather than move forward with other Lead Audio branded products, they decided to spin-off the company into a new sub-brand called Northern Fidelity. I don't exactly know what the motivation was behind this move - perhaps they simply concluded "Lead Audio" was not catchy enough, though it's still referenced along side the new name. Northern Fidelity products will be recognized by their unique appearance - see my pictures and you'll instantly know what I mean. The first product is the subject of this review: the NF DAC. Coming soon will be two different versions of the NF AMP - one based on more traditional analog amplification, and one sporting a PWM design, which seems to me like an updated version of the LA-200. Northern Fidelity does not have a USA distributor at time of writing, but hopefully that will soon change. They do have more than 10 distributors throughout Asia and Europe, and can hopefully accommodate requests from the USA should someone be interested in buying. Suggested retail price is $700 but the resellers are free to do whatever they want based on their unique economic situation. [/size]
[size=small]  [/size]
[size=small] DESIGN[/size]
[size=small] The first thing that stands out about the device is the curved design. It remains a somewhat understated device overall but the curve gives it some definitely flair and helps it stand out in an increasingly crowded segment. This is a relatively compact DAC and doesn't weigh much at all - an external switching power supply means no transformer inside the case to contribute heft. The wall wart supply was also featured on the LA-200 and though I was initially worried about not having the expected linear power supply, it didn't end up being a problem in that instance... so we'll see if the NF DAC follows that same path. As with the LA-200, there is some fairly extensive on-board voltage regulation, so it's not as if everything rests in the hands of that little wall wart. [/size]
[size=small]  [/size]
[size=small] Worth noting: since Northern Fidelity isn't yet officially distributed in the USA, the bundled PSU needed some assistance. While it is universal in terms of voltage, physically the plug did not fit. It required a cheap adapter to create the proper prongs for my area. No big deal, the adapter was just a few dollars anyway - it's simply changing the prong layout, not messing with voltage at all.[/size]
[size=small]  [/size]
[size=small] The NF DAC is definitely an "all-in-one" type device. On the input side, it has coaxial and optical SPDIF as well as asynchronous USB. Coax and USB are both capable of 24-bit/192kHz, while Toslink has a maximum sample rate of 96kHz (as is common for that type of interface). Outputs include separate RCA jacks for fixed and variable output, XLR outputs (fixed only), and of course the headphone output. The front panel is simple and efficient - one button toggles between the three inputs, another button toggles the four outputs, and each has its own LED indicator. Only one output (the selected one, obviously) is active at any given time. A volume knob applies only to the variable RCA and the headphone output.[/size]
[size=small]  [/size]
[size=small]
 

 

 

 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] Internally, the device uses a good selection of hardware: XMOS USB implementation, TI PCM1796 DAC chip, TI SRC4392 asynchronous sample rate converter, very high quality clock paired with a dual-stage buffer, and LM49723 opamps - 4 of them for for I/V conversion and buffering of the output stage, and 2 more for the headphone section. Volume control appears to be handled in the digital domain, probably through the PCM1796 itself which does offer that function. All outputs get their own relays and switching between them results in a mild audible clicking noise, but no unwanted pops through the actual outputs - which is of course the whole point of the relays. [/size]
[size=small]  [/size]
[size=small] Overall layout:[/size]
[size=small]
 
 
 
Master clock with dual-stage buffer:

 
 
 
XMOS USB:

 
 
 
PCM1796 DAC:

 
 
 
Dual LM49723 opamps for the headphone stage:

 
 
 
Output stage using quad LM49723 opamps and relays:

 
 
 
SRC4392 combo chip handling ASRC plus DIR duties:

 
 
 
Outputs:

 
 
 
Front panel is nice and thick:

 
[/size]
[size=small]  [/size]
[size=small] Remember the puny wall-wart power supply? Don't feel too bad about it. The NF DAC uses some tricks like regulators from On Semi augmented by low dropout regulators from National Semiconductor as well as strategic capacitors throughout the circuit. As with the LA-200, the thought process here is more about precise power where it's needed instead of a massively overbuilt supply. I normally prefer the satisfying heft of a big PSU, but I can't really argue with the results achieved here.[/size]
[size=small]  [/size]
[size=small] The PCM1796 is what I'd call a second-tier chip - and I mean that with no disrespect whatsoever. With an SNR of 123dB, it's just behind TI's 127dB flagship PCM1792 and its variants. That places it above many of their newer models such as the PCM5122 (112dB). The PCM1796, a 24-bit chip, was later repackaged as a 32-bit model and renamed the PCM1795. Don't be fooled - take a look at the datasheets and you'll find both models are identical, with the 1795 merely adding a 32-bit input capability but not improving anything else. The PCM1796 is a well proven chip, used by the likes of Accuphase, YBA Design, Vincent, Creek, and Bel Canto, just to name a few. Designer Soren Mac Larsen says he tried some of the well-regarded Wolfson chips and they sounded pretty good, but not as good as the TI chip in this particular implementation. The NFD DAC carries over some elements of the earlier Lead Audio products, so its analog circuitry is built around the PCM1796 which is a current output DAC. The Wolfson models are Voltage output so would require more tweaking of the established Lead Audio design to achieve max performance. In the end his choice makes sense to me. [/size]
[size=small]  [/size]
[size=small] The SRC4392 chip, which in this case also functions as a digital audio interface receiver, upsamples incoming signals to double their native rate. So your standard Redbook 44.1kHz tracks get bumped up to 88.2kHz, which has been theorized by some designers (Dan Lavry chief among them) to be a near ideal sample rate for most DAC chips to handle. The SRC4392 has been paired with the PCM1796 (and its cousin the PCM1792 which is pin compatible) many times with satisfying results - Musical Fidelity does it frequently, with their M6CD, M1 DAC, and A1 CD Pro being three examples. Bel Canto and Primare are some other brands to use the same setup though I don't recall their model numbers off the top of my head. My point here - this is a well proven design that's been at the heart of many high quality CD players and DACs costing a lot more than the Northern Fidelity DAC. [/size]
[size=small]  [/size]
[size=small] Noteworthy specs on the device: THD+N (at 1kHz): less than 0.001%. SNR is 120dB (A weighted). Total jitter is less than 100 picoseconds, though we aren't told if that is RMS or what. Line out has a max voltage of 2.7V which is somewhat higher than the usual 2Vrms. The headphone amp can swing 3.6Vrms into a 600 ohm load, and has an output impedance of 25 ohms which is somewhat high for certain headphones and perfectly acceptable for others. Other odds and ends include the SMSC USB3318 USB transceiver, anSTM32 ARM core microcontroller, a CMOS from Macronix, and an EEPROM from Atmel. Clearly this is no simple design with a few opamps and a DAC haphazardly thrown together. [/size]
[size=small]  [/size]
[size=small] EQUIPMENT[/size]
[size=small] I listened to the NF DAC with the following equipment:[/size]
[size=small]  [/size]
[size=small] Transports: Auraliti PK90 with NuForce LPS-1 and Audiophilleo 1 with PurePower, MacBook Air with Audirvana, Dell 17R with JRiver, Marantz DV8400[/size]
[size=small]  [/size]
[size=small] Amps: AURALiC Taurus, Violectric V200, Icon Audio HP8 mkII, Yulong A100, NuForce HAP-100, Firestone Audio Bobby, Stax SRA-12S[/size]
[size=small]  [/size]
[size=small] Headphones: Sennheiser HD800, Beyerdynamic T1, Audeze LCD-2, HiFiMAN HE-400 and HE-500, Heir 8.A, Westone ES5, Frogbeats C4, Aurisonics AS-1b, Cosmic Ears BA4, Stax SR-007mkII[/size]
[size=small]  [/size]
[size=small] Power: APC S15[/size]
[size=small]  [/size]
[size=small] The system is wired via Cabledyne Reference Silver AC, XLR, RCA, and digital cables. It sits on a Salamander Archetype 5.0 rack. I burned in the NF DAC for quite a long time, well over 100 hours, before any critical listening.[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] Good match for the Violectric V200 amp:[/size]
[size=small]
 
 
Sennheiser HD800 with Toxic Cables Scorpion (balanced, but with matching adapter):

 
 
Paired with Analog Design Labs Svetlana 2 SET amp, driving LCD-2 with Effect Audio
Thor cable:

 
 
 
Very similar in size to the Firestone Audio Tobby:

 
 
Auralic Taurus - this is actually the new MKII version, I mostly used the original for
this evaluation:

 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] SOUND[/size]
[size=small] First off, before I start on the Northern Fidelity DAC, I have to comment on how competitive this segment has become. It used to be the case that sub-$1K DAC market was just not all that impressive. You generally wanted to move up higher to find anything really exciting - I remember steering more than one person towards the Musical Fidelity X-DAC v3 ($999) back in 2004 or so. Going much lower than that involved reducing options and severely limiting quality. Fast forward to 2013 - I'd say the minimum cost for a great sounding DAC has dropped significantly. Not only do excellent sounding DACs exist under $1K; there are tons of 'em! You've got some reasonably good ones that don't cost a lot such as the Audioquest Dragonfly, and some step-up models with better sound and/or more features like the Schiit BiFrost and the HRT Music Streamer stuff. And there are some which I consider excellent - the Yulong D100 mkII, Parasound ZDAC, and Resonessence Labs Concero among others. The field is bristling with great choices and at this point it would require something absolutely special to make a dent in this crowd. Keep that in mind as you read on.[/size]
[size=small]  [/size]
[size=small] With that disclaimer established, the NF DAC is a very good sounding device. The presentation is mostly neutral, with a slight inclination towards warmth and fun. It's sufficiently detailed but not at all overly-detailed. It hits hard and deep with surprisingly nice texture in the bass that belies its wall-wart power supply. I also particularly like the way it does air on the top end - present and believable but not in your face or "look at me I'm sooo high fidelity!" Mids come across as slightly rich compared to some of the more flat peers on the market, which of course can be good or bad thing depending on your preferences. As I said, the word "fun" seems to apply well here, with the NF DAC doing a small contribution towards making everything sound a bit better than it has the right to sound. It's certainly not an overly warm, mushy, romantic sounding DAC, but it does tip the scales just a tad in favor of what I'll call "boogie factor". I already hate myself for using that term but I think it sums up what I mean better than anything else.[/size]
[size=small]  [/size]
[size=small] From Mozart to Michael Jackson, Nightfall to Nancy Bryan, what the NF DAC excels at is involvement. It has just the right balance to keep me engaged, but still be aware of the micro details and nuances. This is noticeable whether using XLR output to a Violectric V200 or RCA output to the Icon Audio HP8mkII. I'd say both outputs sound just about identical, which I suppose is a good thing. I also don't notice any difference between the fixed RCA out and the variable option with volume cranked to full scale. Which makes sense as the volume is done in the digital domain, so there's nothing extra in the signal path that would degrade the sound. [/size]
[size=small]  [/size]
[size=small] Speaking of sounding the same - the digital inputs all perform roughly on the same level. The XMOS based USB option does better than a basic DVD player used as transport, but as I try an older Marantz DV8400 (which was reasonably expensive when new, but that was a decade ago) I find SPDIF is just about indistinguishable from USB. And that includes optical as well as coax. I'm thinking this comes from the upsampling process. Some designs (Benchmark DAC 2 for example) have their asynchronous USB input bypass the ASRC process and go straight to the DAC, while all "legacy" inputs get the upsampling treatment. I don't know if that's also the case here but however they are doing it, Lead Audio largely makes transport quality irrelevant. And I didn't notice a difference between the ultra-clean SOtM USB output of my Auraliti server and a more basic USB connection from my MacBook Air running Audirvana. I guess that fits accordingly with the overall them of this device - it's easy to get enjoyable sound out of it. Use any input, any output, (almost) any source, and you'll get satisfying results.[/size]
[size=small]  [/size]
[size=small] For amplifier matching, I enjoyed the NF DAC with most everything I tried, but a few really stood out. The AURALiC Taurus is one of the most resolving amps out there, and gets somewhat picky with sources - it really needs something high quality, or else it just shows the flaws. It sounded really great with the NF DAC, which is among the cheapest DACs that I would choose to pair with the Taurus. It might be the slightly forgiving nature of the NF DAC, but it fared better than some of my more expensive DACs could in this particular combination. I liked how well it did deep bass - again, surprising for the lack of a big linear power supply. I also really liked the NF DAC with the Firestone Audio Bobby amp. Normally I pair Bobby with the matching Tobby DAC ($1100) which is more on the analytical side, and they make a great team. But with the NF DAC, Bobby takes on a different personality, becoming more laid back and relaxed. There's less detail, and transients are not as fast (a strength of the Tobby DAC), but in exchange you get a more flowing presentation that works especially well with potentially bright cans like HD800 or T1. And thanks to the balanced connection, the NF DAC makes the most of the fully balanced Bobby amp, where many other DACs in this price range couldn't do that. I guess the biggest compliment I can give the NF DAC - I'm comfortable using it in a system with amplification and headphones costing far more than the DAC itself. It doesn't even feel out of place in my Stax rig which normally gets a DAC costing 5 times as much.[/size]
[size=small]  [/size]
[size=small] Then we come to the headphone amp, which is something of a mixed bag for me. It's not terrible, not completely objectionable by any means, but I can't shake the feeling of a slight "thinness" dominating the sound signature, no matter what headphones I use. Overall frequency response seems good with no crazy dips or peaks, but I don't feel a lot of grunt in the lower registers. Part of it may be tied to the higher output impedance which means low impedance headphones and IEMs will have a poor damping factor, and multi-armature IEM designs suffer from altered frequency response due to their wild impedance swings. I also hear a mildly intrusive hiss in the left channel which doesn't show up with full sized headphones but is pretty annoying with IEMs. [/size]
[size=small]  [/size]
[size=small] So IEMs are out, but what about full sized headphones? Audio Technicas are out due to (most of them) already sounding somewhat thin already. Grados are out due to the output impedance mismatch. Same with Ultrasones. What's left? Sennheiser HD600 and 650 which actually sound pretty good here, HD650 in particular due to the increased bass it has over the HD600. Higher impedance models from beyerdynamic seem like they would work well too. I'd probably go DT990 in the 250 ohm variety for best results. And then the planar models: since they don't care much about the 25 ohm output impedance, and are both on the warm/darker side, my HE-400 and LCD-2 are fairly good from the NF DAC. With both models, there's a slightly reduced sense of bass impact compared to my other amps, but it still sounds pretty good overall. My Thunderpants planars also do pretty well - clear and involving, with just a hint of lightness.[/size]
[size=small]  [/size]
[size=small] The thing about the NF DAC - it's an all in one device. You pay a little more with the assumption you'll be getting extra features that will come in handy. And with an HE-400 or an HD650, that's exactly how it plays out. With some other headphones? Not so much. As I mentioned, this segment is incredibly competitive, and the NF DAC needs to really perform well to stand out. While I think it does reach a notch or two higher than the $400 Asus STU with regards to DAC sound quality and overall features, it doesn't do much better than the Asus as a headphone amp. And that might be a deal breaker for some. The amp section is definitely not on the level of something like a $500 Yulong D100 mkII with its more advanced output stage. So while it's great to have an all in one, space saving unit, the amp is somewhat uninspiring with a large number of headphones. [/size]
[size=small]  [/size]
[size=small] On the other hand, as a relatively compact and full featured device, the NF DAC perfect for desktop use. I connected it to a pair of Adam Audio F5 active monitors, using USB from a MacBook Air running Audirvana, and it did an exceptional job. I really like the method of switching between active outputs - I leave the line out active most of the time but switch to headphone mode for late night action. Some units like this keep the line out active all the time which means I'd have to manually power down the monitors. And in terms of sound, I paired the fixed output with a Nuforce HAP-100 preamp, and it sounded indistinguishable from the variable output. Which means the NF DAC is basically transparent in that regard. Nice.[/size]
[size=small]  [/size]
[size=small] COMPETITION[/size]
[size=small] As I mentioned, competition is fierce in this price range. The Yulong D100 MKII has been my go-to recommendation at around $500. It certainly looks like a more serious audiophile component, with the linear power supply and the discrete buffer stage on the headphone output. I think the NF DAC surprisingly beats it as a DAC alone. Not by a huge margin, and they both have their own character, but more often than not I'd choose the NF DAC. Which is impressive in and of itself. But for direct headphone monitoring the D100 has a better integrated amp that works with a wider variety of headphones.[/size]
[size=small]  [/size]
[size=small] The Parasound ZDAC ($475) is very close to the NF DAC in sound signature. Parasound comes off as just a little darker which makes for less implied detail and sometimes equates to a more fun, bouncy presentation. Even if we adjust for sound signatures, the NF DAC just seems like a slightly higher resolution device. Both have headphone stages which are fairly selective about what they are happy pairing with. I end up preferring the NF DAC by a small margin, while maintaining a very high level of respect for the Parasound. [/size]
[size=small]  [/size]
[size=small] I definitely like the NF DAC more than the PS Audio NuWave ($999). It seems far more balanced and easy to listen to. Remember when I said the NF doesn't scream for attention? The NuWave is a perfect example of a DAC that does. And it comes across as very obvious, becoming fatiguing in a short period of time. The NuWave is beautifully built and looks like it should be killer, but somehow just misses the mark in my opinion. The NF DAC, while unique with the curved enclosure, does not look like it would be in the same league, but ends up sounding far better - more balanced, more engaging, and ultimately more tonally correct.[/size]
[size=small]  [/size]
[size=small] CONCLUSION[/size]
[size=small] I'm still not positive why Lead Audio had to start a new line, but I have to say I like the name Northern Fidelity, and I love the appearance of the curved enclosure. With matching amplifiers on the way, one could assemble a very attractive desktop system using stacked NF DAC and NF AMP. But aside from looks, does the NF DAC compete in this tough segment?[/size]
[size=small]  [/size]
[size=small] In the end I'd say yes. It's not a slam dunk victory, but the NF DAC does raise the bar above my favorite $500 units. It doesn't compete on the same level as the best $1000+ devices, but neither does it give up a huge amount of performance. So I'd say the MSRP of $700 is appropriate, and I appreciate having a "middle ground" option in that range. With so many intriguing choices out there above and below that price, any major flaw here would be a deal breaker. The headphone output may be just that for some users, but overall the NF DAC is still worthy and deserves some attention. If you like a detailed but slightly smooth presentation that makes everything sound great, and need a good multi-purpose solution, the Northern Fidelity NF DAC definitely has potential. [/size]

 
 
 
[size=small]Not long ago I reviewed the new DAC-100 from NuForce. I was impressed with its dynamic, exciting sound, which focused more on musicality than excruciating detail. Fast forward a few months, I also covered some of the matching Home Series gear over at InnerFidelity[/size][size=small]. I liked the whole lot of it, which was not something I had anticipated. But I did have a few minor complaints. Specifically, I noted the DAC-100 didn't have the same design aesthetic as the rest of the group. As a higher priced model I guess it made sense to have a standout enclosure made of higher quality materials, but it still seemed odd that a person using the DAC-100 with the HAP-100 headphone amplifier would have a stack that didn't quite match. It's close, but not exact. The other issue was regarding duplicated features - the DAC-100 user got a very credible integrated headphone amp, which I could see negating the need for the stand alone HAP-100 unit. I suppose that could be considered good for the consumer and bad for NuForce, but personally I think the target market for nice DAC like this would eventually be after a stand alone amp anyway. I remain torn about integrated amplifiers in higher end DACs - at times they seem like a brilliant idea (assuming they are of decent quality) and other times the feel like an unnecessary expense that will end up not being used. I'm sure readers have their own opinions on the matter which help shape their potential purchasing choices.[/size]
[size=small]  [/size]
[size=small] Not long after that review, I was informed that NuForce (abruptly?) discontinued the DAC-100 and replaced it with their new DAC-80 model. Essentially the DAC-100 minus headphone section, the DAC-80 uses the familiar Home Series enclosure and sells for $795, which is $300 less than the 100. This made some sense to me so I asked them if I could give it a try to compare with the original. [/size]
[size=small]  [/size]
[size=small] DESIGN[/size]
[size=small] The DAC-80 is very similar to the original DAC-100. It's got the same overbuilt power supply with Noratel brand toroidal transformer and extensive array of capacitors and voltage regulation. It's got the same AKM AK4118 digital receiver, the same Nuforce branded USB implementation capable of 24/192 operation, and the same AKM AK4390 32-bit DAC. It also has the Xilinx FPGA doing who-knows-what to help eliminate jitter. The one difference that jumps right out is the output stage - it uses the same pair LM4562 opamps but has no transistor buffer. The DAC-100 had heatsinks packed tightly and the DAC-80 just as an empty spot in that location. As far as I can tell the actual PCB is the same in both models with the DAC-80 losing that part of the output stage plus a few minor changes like different capacitors. Even the USB board still says "DAC-100" on it. [/size]
[size=small]  [/size]
[size=small] The DAC-100 uses a somewhat unique configuration where it drove the headphone stage with one channel from each LM4562 and buffered that with transistors running in class A. The line output used the "other half" of that - which explains why they needed a pair of stereo opamps for a single ended design. The DAC-80 no longer needs to power headphones so it actually could have used a single stereo opamp, but it was likely easier for NuForce to keep things as-is. There's probably also some potential for reduced crosstalk by running each channel from a separate opamp. [/size]
[size=small]  [/size]
[size=small] All this time I was operating under the assumption that the DAC-100 used transistors for both the headphone amp and the line-out stage. But maybe I was wrong - maybe the class-A transistor section was entirely used by the headphone stage, and the line-out was purely opamp based. That's certainly possible and either way it shouldn't take anything away from the excellent performance of that unit. As I read the datasheet for the AK4390 I notice it does voltage output rather than current output. So there's no I/V conversion stage needed. The LM4562 operates as an LPF and the output we get is basically straight from the DAC chip itself. Since the FPGA handles jitter rejection, there's no upsampling scheme involved, which means a very pure signal goes straight from the DAC chip to your amplifier of choice. [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] As you can see, the front and rear panels are pretty much the same as the DAC-100:[/size]
[size=small]
 

 
Internally, everything remains the same was well - power supply filtering:

 
 
Noratel toroid:

 
 
Another view of the 17 caps:

 
 
Overall interior - can you spot the one difference from the DAC-100?

 
 
This lettering is the same:

 
 
Same Xininx FPGA and same PIC microcontroller:

 
 
Same AKM digital receiver:

 
 
This is the actual DAC chip itself. Looks like NuForce tried to obscure the text, but 
I can still read it in certain lighting. Not sure why they hide it - it's a quality modern chip:

 
 
The USB section even says DAC-100 on it:

 
 
LM4962 opamps... getting warmer as far as what's different:

 
 
 
Bingo! There it is! Big empty spot where the output transistors and heatsinks used to be
in the DAC-100:

 
 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] FEATURES[/size]
[size=small] Again, just like the DAC-100, the DAC-80 is a DAC with preamp functionality thanks to its 32-bit volume control implementation. With inputs including asynchronous USB, Toslink, and coaxial SPDIF (x2, transformer isolated), and the included remote, the unit could in fact be a viable preamp for a small system (obviously using digital sources only). With the integrated amp no longer on board, and matching casework this time around, the HAP-100 seems like an obvious dance partner for the DAC-80. [/size]
[size=small]  [/size]
[size=small] The front panel is visibly different from the 100 but functionally very similar. Instead of dedicated buttons for source selection, the 80 borrows ideas from the rest of its Home Series cousins - push the volume knob to cycle through sources, hold it down to enter or exit standby mode. There's an actual power on/off switch on back. Same rate indicators remain in place, looking close but not quite identical to the 100.[/size]
[size=small]  [/size]
[size=small]  
 

 

 

 

 

 
[/size]
[size=small]  [/size]
[size=small] SOUND[/size]
[size=small] After giving it extensive time for burn-in, I set out to give the DAC-80 a listen. Rather than start from scratch, I began with the assumption that the 80 should sound at least roughly similar to the 100. So my initial testing was centered around direct comparisons between the two. If the 80 ended up sounding vastly different, I could then start over and get a feel for it all by itself.[/size]
[size=small]  [/size]
[size=small] Thankfully for me (since the alternative would be more complicated) my initial assumption proved correct. Despite the simplified output stage which no longer has the discrete buffer, I can't reliably tell the 80 apart from the 100. There were times when I actually thought the DAC-80 was ever so slightly better than the 100 - by just a hair - but these were fleeting. So ultimately I'd say they are close enough to be indistinguishable.  [/size]
[size=small]  [/size]
[size=small] This supports my new theory that the 100 used the discrete buffer for headphone duties only. So all this time I was listening to (and enjoying!) a more simple design than I had thought. But that's fine with me - designers should be building around their chosen architecture rather than adding stuff just for the sake of complexity. When the chosen parts call for simplistic design - and the AK4390 appears to do just that - then I'm all for it. [/size]
[size=small]  [/size]
[size=small] You can read my DAC-100 review to hear more about my impressions of the sound. In a nutshell, it's a somewhat musical sounding DAC, very dynamic and exciting. Definitely a different sound compared to the recent trend of hyper-detailed DACs. Not that detail is poor - in fact top end air and extension is on the strong side, but it's refined enough to avoid that "digital" feel. I particularly like it paired with my Analog Design Labs and Icon Audio single-ended triode amps. I can use different DACs and amps to assemble a more detailed system, or one that does better vocals, or one with more finesse. But for sheer musical, toe-tappin' fun, the NuForce/SET amp combos are tough to beat. And I don't mean that in a disparaging way, where the sound is slow, syrupy, murky... It remains fairly balanced for the most part - it's just got some extra excitement there compared to more neutral options. [/size]
[size=small]  [/size]
[size=small] One of my chief questions, the reason I was interested in evaluating the DAC-80 in the first place, was to see what amp I could pair it with in order to match the DAC-100. As an all in one design, I thought the DAC-100 was a great value and an exceptional match with the HD800 and T1. The 80 costs $300 less - what can we get for that price in terms of stand alone amplification? The list of potential suspects is not huge - the Matrix M-Stage is really the only one I currently have that doesn't exceed the $300 difference. The Lake People G103 (in standard form, not the Pro version with XLR) squeaks in at less than $300, but I sent mine to Tyll Hertsens for measurements so I don't have it available right now. I decided to stretch things a bit and include the Yulong A100 which exceeds the budget by $60 or so depending on who you buy from. And then of course I had to try the DAC-80 paired with the HAP-100 which combined sells for $300 more than the DAC-100 alone. [/size]
[size=small]  [/size]
[size=small] The DAC-80 plus Matrix M-Stage is actually a really great combo. I'm currently running the M-Stage with the class A biased OPA627 opamps - there may be some better opamp choices out there, but this one is pretty darn good already, and is available from Tam Audio around my target budget for this comparison. I had loaned out my M-Stage for a long time and when it recently came back, I was surprised at how well it holds up. I think overall the DAC-80/M-Stage combo is a better performer than the DAC-100 alone, with a few caveats. The M-Stage brings to the table a quieter background and a more seductive midrange. This is welcome with some headphones like LCD-2 and Denon D7000 where the DAC-100 could sometimes feel a little distant with vocals. To some degree the effect remains, no doubt due to the character of the DAC itself, but the M-Stage seems to mitigate it compared to the integrated amp section. But when I switch to the HD800, a headphone known to pair well with the M-Stage, the integrated amp still pulls ahead. There's just a synergy thing going on where I really enjoy it. The Beyerdynamic T1 also seems to do better from the DAC-100, with a smoother and more controlled top end and better bass extension. Overall I'd say the M-Stage wins more often than not, but when the DAC-100 shines it really shines brightly. [/size]
[size=small]  [/size]
[size=small] Next I switched to the Yulong A100 which sells for roughly $360. The A100 is a killer budget amp, very detailed and clean. With the DAC-80, the result is again very good with a wide variety of headphones. But this time around it's a little more thin and tilted towards the top end, so doesn't go as well with the K701 or the Audio Technica models that are already somewhat bright and/or bass shy. With HD650 or Denon headphones, the A100 is exceptional and definitely improved over the DAC-100 - tonal balanced ends up being similar but detail and clarity are superior. But again the HD800 and T1 do best with the integrated unit. A minor thing, but the A100 doesn't stack well with the DAC-80, as it's deeper than it is wide (and the NuForce is the other way around). In the end my preference shifted based on my mood - do I want more detail and accuracy, or am I in the mood to rock out? [/size]
[size=small]  [/size]
[size=small] Finally, NuForce's own HAP-100. Remember, this combo is $300 more than the DAC-100. I notice a significant improvement in the low bass region, with more believable grunt and extension. I notice superior imaging and accuracy in the soundstage. And those vocals, which had been slightly recessed at times, were almost as forward as I'd like. That last bit is tied with the DAC character and will never go away completely, but the HAP-100 is one of the best I've heard for bringing those mids forward. [/size]
[size=small]  [/size]
[size=small] The HAP-100 also seems more comfortable with planar headphones. Not that the DAC-100 is terrible on its own, but the dedicated amp seems to have more oomph (to use the scientific term). Mostly this shows up in the extreme low frequencies, which real instruments don't actually make. It just feels more solid. I can make either unit gracefully clip if I play music loud enough but the HAP-100 holds out longer before going there.... not that either really has an issue at normal volumes.[/size]
[size=small]  [/size]
[size=small] By far the largest improvement comes with respect to noise floor. My biggest complaint about the DAC-100 was that it didn't really work so well on more sensitive headphones or any IEMs. There was a clearly audible hiss that not only appeared with my CIEMs (which is fairly common with desktop amps) but also with full sized headphones like the Ultrasone Signature Pro or Grados. I'm not talking about some vague noise floor issue - it's an actual hiss, loud and clear and highly obtrusive with certain music. As much as I like the DAC-100, it's basically off limits to those certain headphones. The HAP-100 brings a silent background to the table, even quieter than the A100 and M-Stage. This means significant gains in low level resolution, which leads to a more believable presentation. Custom IEMs like the Frogbeats C4, Heir 6.A LE, or the JH13 Freqphase are excellent at resolving those little details, so the improvement is very much appreciated. [/size]
[size=small]  [/size]
[size=small] I also used the DAC-80 in my speaker rig with the matching STA-100 amp. It makes perfect sense in that application because speaker users won't necessarily care about the integrated headphone amp being removed. You still get the same high-quality DAC performance, the same well implemented 32-bit digital volume control with remote capability, and this time you get perfectly matching aesthetics. Add the HAP-100 for headphone capability and multiple analog inputs, and you've got a formidable stack for $2,000 that has great headphone amplification, truly versatile preamp capabilities with all sorts of inputs (digital and analog), and plenty of power for most speakers. The DAC-100 really wouldn't add a thing to that equation, so I can see why NuForce went in this direction instead.[/size]
[size=small]  [/size]
[size=small] CONCLUSION[/size]
[size=small] The DAC-100 was discussed in the most recent HeadFi gear guide as being one of the best sounding DACs under $1500. I've heard a lot of DACs in that range and I'd have to agree - the DAC-100 is certainly up there on my list. And yet NuForce already discontinued that model. Why? Simple really - the DAC-80 makes more sense. It better matches the rest of the home series components in both price and appearance, and helps make a better case for the HAP-100 as a complimentary add-on. Oh, and it loses none of the rich, dynamic sound that made the original model so enjoyable. [/size]
[size=small]  [/size]
[size=small] Will the integrated amp in the DAC-100 be missed? With HD800 and T1, absolutely. Those made for dynamite combos straight from the DAC-100, and for users of those headphones I'd say check around for remaining DAC-100 stock. For most everyone else, the DAC-80 is the way to go, and I completely understand why NuForce made the switch. [/size]

 
 
 
[size=small] Effect Audio started in 2009, making aftermarket cables for enthusiasts. They went international in 2011, selling their custom creations via eBay as well as their own website. By 2013 they are one of the more well known options and have amassed a collection of positive reviews around HeadFi and other places. Effect primarily deals with cable upgrades for IEMs but has recently expanded into full size models such as Sennheiser and Audeze. I've been curious about them but never had a chance to work them into my busy schedule. Until now.[/size]
[size=small]  [/size]
[size=small] Models[/size]
[size=small] Effect has a range of IEM cable options. Currently, their lowest priced model is the Crystal cable which sells for a mere $50. Their highest model at the moment is the Odin which sells for $199. From $50 to $200 with many stops in between, it seems clear that Effect is interested in capturing the budget market rather than playing in the stratospheric range where the cable costs more than the IEM itself.[/size]
[size=small]  [/size]
[size=small] I confess to being slightly confused by the model lineup: Effect lists their new Thor IEM cable as being their "flagship product". It comes in two variations - UPOCC cryo treated Silver Plated Copper for $129, or UPOCC cryo treated Silver for $189. That's fine and dandy but remember the Odin at $199? Seems like the most expensive model would tend to earn "flagship" status. In the North mythology, Odin is the greatest and the oldest of the Æsir and Thor is his most noteworthy son. As strong as Thor is, Odin remains the top dog. So I'm not clear on how the Effect Audio pantheon really shakes out. Whatever the case, the focus here is on the Thor cable in two different variations.[/size]
[size=small]  [/size]
[size=small] The first cable I got from Effect is the Thor OCC SPC for IEMs. I got mine in "Westone 4R" style so it works with all my custom IEMs (some of which are actually from Westone, while others are from various different brands). Other connectivity options include Sennheiser IE8, Shure SE535, and Ultimate Ears TF10. Termination is a 1/8" plug from Oyaide in either straight or right angle. The price is $129 regardless of options, it comes in a 1.2 meter length, and is available only in silver color.[/size]
[size=small]  [/size]
[size=small] The other cable I got is the Thor OCC Silver headphone cable. This one is available for most popular headphones including Audeze LCD-2 and LCD-3, HiFiMAN HE-series (works with all of them), Sennheiser HD580/600/650, and Sennheiser HD800 (which costs $50 extra due to the expensive connectors). Termination is in the same Oyaide 1/8" plug and it comes with a 1/4" adapter. Length is 1.5 meters and sleeving is available for an extra $30. I ended up getting the Audeze model to use with my LCD-2, which sells for $219 plus the $30 sleeving for a total of $249. [/size]
[size=small]  [/size]
[size=small] Both types - IEM and headphone cables - seem to use the same construction. It's a quad-braid design which is very flexible, more so than most any of the aftermarket cables I've tried. I don't know if the full-size cables are of a thicker gauge than the IEM cables, since my Audeze cable has the sleeving which blocks my view of the action. The sleeving is very nice though - individually wrapped for each strand in an ultra-soft "shoelace" material, similar to what you'd see from other brands like Norse or Q Audio. [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] The Experience[/size]
[size=small] Right off the bat, I was impressed with the Effect cables as far as their flexibility. The Thor IEM cable I'd say was more flexible and easy to manage than any of my others from Beat Audio, Toxic Cables, and 93 East, though still not quite as pliable as the Heir Audio Magnus cable (but it was close). The build seemed in line with my 93 East Stage93 cable or my Toxic Cables SPC Viper, both of which I consider to be excellent cables. [/size]
[size=small]  [/size]
[size=small] The Thor Audeze cable was even more flexible - I've never had my hands on the Q Audio stuff so maybe they achieve this same level of flexibility, but it's really quite remarkable. With the cotton sleeve looking like a shoelace, it seems as if I could actually tie it in a knot without much resistance. Not that I want to try that, but that's how flexible it is. One suggestion I have for Effect is to offer a larger selection of terminations for these headphone cables. IEMs are fine with 1/8" jacks but I usually want a big 1/4" jack on my full size headphones. Nothing wrong with the Oyaide 1/8" plug but I think people would like a wider selection, including balanced options.[/size]
[size=small]  [/size]
[size=small] As for listening: I don't like to go into huge detail about sonic signatures of cables. It's no fun to sit there analyzing them in that way, and even less fun to read about. So I'll keep this relatively simple and brief.[/size]
[size=small]  [/size]
[size=small] For the Thor IEM cable, I compared it mainly to the Toxic Cables SPC Viper. Both use OCC silver plated copper. The Viper sells for around $180 based on today's exchange rate, so it's the more expensive cable overall. In comparison, the Thor is more flexible and easy to deal with. But to be fair my Viper is a prototype model in a thicker gauge. The regular version should come closer to the flexibility of the Thor but probably still doesn't quite match it. Both are very nice and seem durable enough to last for actual portable use.[/size]
[size=small]  [/size]
[size=small] For sound signature, the Viper seems to have a bit of a midrange glow to it. Not an extreme coloration - it's very subtle. I also notice superior bass extension and fullness in the deepest low frequency range. This is compared to the standard Westone or Heir or Unique Melody cable that ships stock with most CIEMs. In comparison, the Thor sounded pretty similar in quality but different in the specifics, with a slightly less noticeable midrange boost and more of a focus on the lows. As always with cables, this is a subtle touch of character rather than an "in your face" new sound signature. [/size]
[size=small]  [/size]
[size=small] I tended to prefer the Thor paired with neutral or thinner sounding CIEMs - the Frogbeats C4 was a good match, and the Heir 4.A, and especially the original Cosmic Ears BA4. The BA4 in particular paired exceptionally well with the SPC Thor, benefiting from the extra low end clarity and grunt. The Viper was a better match for different IEMs which need no assistance in the bass department. That would be the Heir Audio 6.A LE, the 1964 Ears V3, and the Lear LCM-5 among others. Overall I'd say the Toxic Cables Viper is the slightly better sounding cable but not by a huge margin. Considering the price difference, and the fact that Toxic Cables is in my experience one of the best brands around, it's pretty impressive that the Thor can approach it for less money. [/size]
[size=small]  [/size]
[size=small] By selling cables for big headphones rather than "just" IEMs, Effect Audio places themselves among a whole new level of competitors. There are just so many brands out there making headphone cables, from big names like Cardas to small companies that only a HeadFier might know about. Some of these have launched IEM cables or plan to do so in the near future, but I'd still say there are more brands catering to full size headphones. At $249 for the OCC Silver version with sleeving, the Effect Thor doesn't really qualify as a budget choice, but neither does it seem too extravagantly priced. [/size]
[size=small]  [/size]
[size=small] I used the Thor OCC Silver with my Audeze LCD-2. I've got the latest version in bamboo and I normally use a Charleston Cable Company Auric Ohno cable with it, or else the stock balanced cable. Charleston has switched gears and no longer offers the Auric Ohno as their top model, having replaced it with a supposedly equivalent proprietary UP OCC material. The Charleston cable, at $280, is just a bit more expensive than the Thor.[/size]
[size=small]  [/size]
[size=small] The Thor did exactly what I had hoped for with the LCD-2 - it slightly extend the treble response without going overboard, and improved soundstage by a small but noticeable amount. And guess what? That's exactly what my Charleston cable also does. Interesting, because one is pure silver and the other is copper with no silver. I'm still not convinced that any particular material always sounds a certain way - it has more to do with quality than any one particular ingredient. But I think some people would be surprised to hear these two cables, with very different designs and construction, performing so similarly. The stock Audeze cable is no longer terrible (I hated the early cable they used which was extremely thick and stiff) and I definitely wouldn't recommend a $250 cable as an absolutely necessary add-on. The Effect Audio Thor is better suited for people who already have a reasonably nice setup and want to extract the last bit of performance from it. [/size]
[size=small]  [/size]
[size=small] Conclusion[/size]
[size=small] The Effect Audio Thor cables are nice. Real nice. If flexibility is very important to you, they could be some of the best cables out there. In terms of sonics, both the Silver and the SPC are competitive within their respective price ranges. Effect has been around for a while and seems to have built up a respectable reputation for service and quality. And the Thor cables, despite their reasonable price tags, don't feel out of place in my rather expensive system. If you're in the market for a cable upgrade, definitely give Effect Audio a good look. [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] Pictures[/size]
[size=small]  [/size]
[size=small] No memory wire - just a thin layer of clear plastic wrap:[/size]
[size=small] [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] Notice the custom "Effect" labeled connectors, which appear to work with flush or[/size]
[size=small] recessed sockets. Also see how the cable takes shape even without memory wire,[/size]
[size=small] after just a few uses. It's very comfortable:[/size]
[size=small]
 
 
 
Custom Y-split and simple clear slider - no wooden choker on these:

 
 
 
I got the angles Oyaide plug:

 
 
 
SPC Thor next to 93SPEC silver cable from 93 East:

 
 
They look pretty similar:

 
 
 
With Beat Audio Cronus, which takes a very different approach:

 
 
 
With puny stock cable (which is already turning green):

 
 
Next to Toxic Cables Viper - notice how the Viper can't quite coil up as easily:

 
 
 
Next to 93PC from 93 East, which is (obviously) copper and a lot thicker too:

 
 
 
Thor Silver Audeze cable:

 
 
 
Mini-XLR plugs look like Rean brand but don't have a label:

 
 
 
Nice sleeving:

 
 
 
Next to Charleston Cable Company Auric Ohno:

 
 
 
Notice how the Thor can make a tight curve, while the Auric Ohno is unable to bend
in the same way - this was as tight of a curve as it could hold, while the Thor could 
have bent more if I wanted:

[/size]
[size=small]  [/size]

 
 
 
 
 
 
[size=small]Yulong audio has been steadily building up their portfolio. The D100 was a brilliant DAC that fared well at the time against competitors in the $1K range - but it sold for under $500. The D100 mkII took things up another notch, adding further refinement and helping the D100 stay current against an increasingly tough range of competition. The Sabre D18 was the initial reference DAC, packing the flagship ES9018 Sabre Reference chip at a price - just $699 - far lower than any competitors using that same chip. But the D18 wasn't for everyone; its lack of USB and warm, smooth presentation, while both deliberate, made it less than ideal for some users and their systems. I once heard someone describe it as "without a doubt the warmest sound I've heard out of a DAC", which they meant in a totally complimentary way. I personally wouldn't take it quite that far the but fact remains - Yulong could use a proper flagship, positioned above the D100 mkII and having a more broad appeal than the D18.[/size]
[size=small]  [/size]
[size=small] Enter the new DA8. This $1299 device aims to cover all the bases and indeed it seems to tick all the boxes one might expect: hi-res USB with DSD capabilities, ES9018 DAC in quad-mono configuration, beefy linear power supply, selectable digital filters, high quality integrated headphone amp, balanced outputs, preamp functionality (defeatable for pure DAC mode), informational LCD display.... pretty much every significant feature one can imagine, is found in the DA8.[/size]
[size=small]  [/size]
[size=small] As always, I recommend Grant Fidelity for customers in the North American region. Not only are they authorized Yulong dealers for the area, but Rachel from Grant Fidelity is bilingual and can assist with translating questions directly to Yulong himself. We have her to thank for arranging this review as well as for translating my questions back and forth with the designer. Thanks Rachel![/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] DESIGN[/size]
[size=small] Most prior Yulong equipment uses a similar enclosure, and the DA8 doesn't deviate from that design choice. In this case I think it's the exact same enclosure as the P18 power conditioner unit; or at least very close to it, with some side venting ports added. Which means it's slightly taller than the D18 or D100 enclosures, by just a small amount. I got my DA8 in black which is contrary to all the silver Yulong gear I own - it looks quite handsome in the dark color, though I'm sure silver is equally dashing. Weight is around 6 pounds and feel is quite substantial. We see attention to detail even in the small things - check out the vibration-reduction method used on the feet.[/size]
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[size=small] Browsing pics, one immediately notices the 2.4" display as being the centerpiece of the front panel. I was a bit concerned about how obtrusive it might be, but after spending time with it I actually quite like it. As this is a more complex DAC with more options, it requires some type of interface - the D18 could get by with a few LED lights but that wouldn't fly as well in this case. So the LCD makes sense. With it, I can track selected input and incoming sample rate, phase inversion, filter options, jitter attenuation, and volume. The order, top to bottom, corresponds with the neighboring buttons which change those very settings. One wonders if a touch screen display would be a better option, but after using the device I think that would require more real estate than the DA8 can spare. After 5 seconds the display gets dim and almost looks like printing on the panel rather than a lit display. I'll try to capture it in my pics, but this was a big concern of mine - would it be too bright, or behave strangely, or...... but not to worry, Yulong nailed it. Aside from the display, the volume knob is worthy of mention. It controls the integrated volume function which applies to the headphone section as well as XLR and RCA line-out. Volume is handled in the 32-bit domain in 80 linear steps, which means the DA8 can act as a legit preamp. Pressing the knob deactivates volume control and headphone out, transforming the device into a pure DAC. Conveniently, the DA8 remembers prior settings and starts back up just the way you left it. [/size]
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[size=small] The rear panel shows a bounty of connectivity options. We get 1 each of USB, coaxial, optical, and AES/EBU inputs. We get RCA and balanced XLR outputs. And we have an IEC cable socket with a switch for selection voltage, as the DA8 is a universal device. Yulong would probably recommend his D230 power cable as an appropriate upgrade, which at $99 is priced low enough for cable agnostics to give it a try without breaking the bank. [/size]
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Cabledyne Silver Reference cables (except for the NuForce Impulse USB)

 
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[size=small] Yulong is very kind to provide a handy diagram showing the layout of the DA8:[/size]
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[size=small] Let's analyze that a bit. The power supply features a Plitron toroidal transformer, using Linear Technology LT1129 low dropout voltage regulators and LT3021 very low dropout voltage regulators in a two phase design along with LM337T and LM317T.. These are mated with Wima MKS2 capacitors for smoothing and filtering. Over 13,000uF worth of Panasonic FC caps help stiffen thing up. Idle noise is very low, at a mere 1.5uV which is improved over the D18 (which was already quite good to begin with).[/size]
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[size=small] The USB input is separate board from Amanero Technologies, called the Combo384. This is a new board which is creating something of a stir in the DIY community due to its high performance and low price. Several knowledgeable DIY folks have mentioned to me that they get the best results using XMOS and Amanero USB solutions, with the latter being significantly less expensive than the former. I speculate this choice is part of the reason why Yulong could build a device of this caliber yet keep the price low. It can accept PCM signals as high as 32-bit/384kHz (DXD tracks). It can also do DSD including DSD64, DSD128, DSD256 and DSD512. A special ASIO driver is required to unlock some or all of these features. I use a Linux based server which connects to the DA8 without problems and plays "basic" DSD64 tracks without issue. [/size]
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[size=small] Worth mentioning - although the Amanero datasheet calls for power over USB, the DA8 instead uses its own power supply to power the board. Thus it will work with aftermarket or modified USB cables carrying data only, theoretically allowing for better sound. My music server uses a SOtM USB card with the option of disabling USB power, and I did so - the DA8 worked just fine, though I don't think I noticed any difference in sound. Perhaps if I was using a basic PC instead of a dedicated server, it might make a difference. Or not. Who knows. [/size]
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[size=small] Also worth mentioning is the fact that Yulong developed custom firmware for the Combo384 in order to make it play nicer with the ES9018. Yulong couldn't go into more detail about this as it's something of a trade secret, but suffice to say this goes beyond what a DIY designer would likely be able to accomplish. [/size]
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[size=small] The heart of the DA8 is the processing engine. Obviously it has the ES9018 Sabre DAC from ESS Technologies, used in a quad-mono configuration just like the Sabre D18. It uses a custom made, very low phase noise clock (-145dB). And it has a proprietary Yulong "digital signal buffer" which enhances and routes incoming digital signals. The ES9018 has a built-in DIR which has proven somewhat finicky, rejecting signals from mediocre sources. Some users reported issues with the Yulong D18 (and other DACs without an outboard digital receiver) so I'm sure that's what motivated Yulong to try something new. There may also be some additional jitter rejection involved in the process, to augment the onboard ESS jitter reduction. [/size]
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[size=small] ES9018 DAC and custom clock:[/size]
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Digital Signal Buffer:

 
 
 
 
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[size=small] The analog output stage is built around five of the highly regarded Analog Devices AD797 opamps for I/V conversion and low-pass filtering, paired with dual OPA1632 used as a buffer. OPA1632 is not seen all that often, but found in a few well regarded designs like the Anedio as well as the Buffalo DACs. The headphone stage takes the signal from the OPA1632s and adds a discrete Class A diamond buffer based around transistors from ON Semiconductor. The preamp and headphone stages can be disabled, along with volume control, making the device a pure DAC only with a fixed output. [/size]
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[size=small] Headphone stage with ON Semi transistors in Class A: [/size]
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Output stage with AD797, OPA1632, and more Panasonic FC caps:

 

 
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[size=small] Here are the complete specs as listed by Yulong:[/size]
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1. Inputs: Optical, Coaxial and AES support 16-24bit 44.1-192kHz
2. USB input support PCM 16-32 bit, 44.1Khz 48Khz 88.2Khz 96Khz 176.4Khz 192Khz 352.8Khz 384Khz DSD64,DSD128 - On Windows DSD256,DSD512
3. USB input support Mac OSX, Linux with UAC2 compliant kernel
4. KS/Wasapi/WDM/ASIO Drivers for MS OS XP to Win8 32-64bit 
5. SNR: -135dB.
6. Dynamic Range: 133dB.
7. THD+N: <0.0002% 
8. Frequency Response: 20-30KHz - 0.2 dB
9. Output voltage: RCA 2V; XLR 4.2V
10. Left/right channel crosstalk: -135dB
11. Power Consumption: <30W.
12. Single ended heaphone output: 600 Ohm: 70mW; 300 Ohm 150mW, 150 Ohm: 280mW, 32 Ohm: 1W
13. Dimensions: 250*180*55mm (10" W x 7" D x 2 1/2" H)
14. Net Weight: 2.5kg / 5.5 lbs
15. Color option: silver or black 

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[size=small] So let's see.... extremely low THD+N, very high dynamic range, spectacular SNR and crosstalk numbers.... there's really not much out there that can match or surpass this device in terms of measurements. And we've had a peek into Yulong's workshop where he has extensive testing equipment so it's not like he merely lists specs from the DAC chip itself (as many others are guilty of). He even provides some measurement charts:[/size]
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As you can see, this device measures impeccably - as good or better than almost any DAC I've seen, regardless of price.
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[size=small] Folks looking for an all in one device will notice the headphone amp specs - output impedance is suitably low and it's plenty powerful for most headphones, doing especially well into lower impedance loads. Most planar headphones should see between 500mW and 1,000mW from the headphone amp, meaning they should be driven with plenty of authority.[/size]
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[size=small] EQUIPMENT[/size]
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[size=small] This is the associated gear I used to evaluate the Yulong DA8:[/size]
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[size=small] Transport: Auraliti PK90 with NuForce LPS-1 power supply, Dell Inspiron 17R, Audiophilleo AP1+PurePower, MacBook Air, Denon DVD-2200[/size]
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[size=small] Amp: Violectric V200, Icon Audio HP8 mkII, Analog Design Labs Svetlana 2, AURALiC Taurus, Firestone Audio Bobby, Yulong A100, NuForce HAP-100, Yulong A18[/size]
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[size=small] Headphones: Sennheiser HD800, beyerdynamic T1, JH Audio JH13FP, Westone ES5, Stax SR-007mkII, Thunderpants, Audeze LCD-2, HiFiMAN HE-400 and HE-500, Heir Audio 8.A, Frogbeats C4[/size]
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[size=small] Speaker setup: NuForce STA-100 or Parasound Halo A23 driving Sjofn HiFi (the clue) monitors[/size]
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[size=small] Cables: Cabledyne Silver Reference for AC, SPDIF, RCA and XLR interconnects, Charleston Cable Company Auric USB, NuForce Impulse USB, lots of aftermarket headphone cables from Toxic Cables, Charleston Cable Company, Beat Audio, and 93 East[/size]
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[size=small] Power: APC S15 conditioner, Yulong P18 [/size]
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[size=small] LISTENING[/size]
[size=small] My first impression of the DA8 was that it combined the best qualities of the D100 mkII and the D18. Which is pretty much what I had hoped for, in a best possible scenario. It captures the warmth and richness of the D18 but has more of the airy presentation of the D100 mkII, while besting them both in most categories. Soundstage, low frequency texture, midrange clarity and refinement.... I could go on and on, but in summary - the DA8 is simply the best Yulong DAC yet. At that point I knew it would be tough competition for my other favorite DACs.[/size]
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[size=small] I connected it straight to my Auraliti PK90 server and was able to play hi-res PCM material as well as DSD64 tracks without issue. Great recordings, such as DSD titles from Channel Classics and Blue Coast Records, sounded spectacular. Clean and transparent but also very weighty and muscular, with a sound that could very accurately be described as "analog". Same with Reference Recordings HRx 24-bit/176.4kHz titles, and various other hi-res PCM tracks from a variety of sources. Even "mere" 16/44.1 recordings sound absolutely fantastic on this DAC - XRCD releases, MFSL remasters of Sinatra and U2, DDC Gold editions of Metallica, the list goes on and on. The DA8 handles these all with supreme competency - if you want a high-end DAC that does justice to your favorite "audiophile" recordings, this definitely a good choice.[/size]
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[size=small] With a lot of DACs, however, the flip side of that coin is poor recordings sounding pretty terrible. My Anedio D2 is like that to some degree, as is Yulong's own D100 to a lesser extent. Their revealing nature will clearly lay bare all the flaws inherent in a crappy, overly compressed modern track, or a highly "digital" sounding album from the 80s. The Yulong D18 earned somewhat of a reputation for being one of the more forgiving DACs in that area, which won it considerable acclaim from users looking for that type of performance. The one problem it seemed to have - some found it overly smooth on the top end. It made everything sound great, but at the expense of a little air and accuracy on better recordings. I recall a very enthusiastic HeadFier who had tried many DACs for his home studio. He was absolutely thrilled with the D18 at first, calling it one of the best he had ever heard. As time went on, however, he determined the D18 was making his mixes sound too good. It wasn't revealing enough of flaws. He loved the way it sounded but decided it wasn't suitable for his purposes, so it had to go. Despite that, he stated he recommended it highly for other people who just want to listen and enjoy.[/size]
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[size=small] I don't recall what that gentleman ended up with. I know it was more expensive than the D18 - maybe Violectric V800 but I'm not positive. If the DA8 had been available then, I suspect it would have made him extremely happy. It's got enough articulation and delicacy on the top end to really help show a good recording from a bad, while not quite slaying the bad ones as some other DACs would do. And there's also an improvement in other aspects too.[/size]
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[size=small] Soundstaging is simply phenomenal - among the absolute best I've heard. It has an actual "feel" to it, like being there in the performance venue. A lot of DACs can give the impression of some arbitrary width or depth, and it sounds great at first, but eventually you notice everything sounds about the same. That's not how it should be. The DA8 will showcase a large hall presentation when called for, or a tight, intimate setting if that's needed. It will clearly show the difference between, say, a studio album and a live performance of the same songs. And example of this would be one of my favorite bands - Dengue Fever. Their album "In The Ley Lines" was originally released as part of the B&W Society of Sound. It features several live performances of previously released songs, and the difference in quality is very obvious. Their first few albums were full of great music but with a low budget for studio time, they didn't sound all that great in terms of recording quality. With the involvement of B&W, these redone versions are quite good, showing a depth and spaciousness absent in the original versions. The DA8 makes the improvement very clear without sounding terrible when playing the older recordings. On a side note, "In the Ley Lines" recently returned to the market (Society of Sound titles often have limited to no availability once they expire from the catalog) as a general release that anyone can buy - and I highly recommend it! Bonus points for being available in FLAC as well as Apple Lossless format. Here's the link. [/size]
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[size=small] Low frequency extension is a definite strength of the DA8. This thing has a certain "drive" that will probably cause people to break out the word "analog" again, just like they did with the D18. It's just an effortless presentation. All the detail in the world is great but if it doesn't move you, then what's the point? The DA8 succeeds wildly here, because it captures some of the best elements of both musical and analytical DACs. I've heard so many CD players and DACs which skew too far in one direction or the other. And I'm not talking about cheap DACs, or $800 devices, or even $1500 devices. [/size]
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[size=small] Go on Audiogon and look in the Digital section. Use the brand new stuff as a reference so you don't have to worry about depreciation. You'll quickly discover that triple digit pricing is the exception rather than the rule. $3,000 may sound like a lot of money for a DAC (and surely it is) but really that doesn't buy you anything that stands out as being expensive or super-high-end. You can drop $5,000, or even $10,000 and still have just an "upper-mid-range" DAC according to pricing. Boulder, Wadia, Soulution, MBL, Zanden, dCS, Acoustic Arts, Ayon, Metronome..... the list is endless. And the funny thing is, more than a few of these companies are not even true "specialists" in the digital realm. A lot of them simply use a decent OEM player or DAC design, with a massively overdone enclosure, and upgraded boutique capacitors etc. You can easily spend many thousands of dollars on a CD player or DAC that sounds truly mediocre by any reasonable definition of the word. I implore you not to do so.[/size]
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[size=small] With the Yulong DA8, we get the benefit of the designer having worked for many years as an engineer in the telecommunications industry. This is not some armchair audiophile tweaking things by ear - Yulong has a dedicated facility with six figures worth of equipment including a Prism Sound dScope Series III audio analyzer. Armed with the right experience and education, the right equipment, and what seems to be a good idea of what real music sounds like, Yulong has yet to disappoint. His designs always compete well at their respective prices and even above, and the DA8 is no different. For a neutral-yet-engaging sound, large and precise soundstage, spectacular texture, subtleties and microdetail, the DA8 is a real winner. [/size]
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[size=small] A few miscellaneous comments about the DA8 in action:[/size]
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[size=small] First, the USB implementation is top notch. I've never dealt with the Amanero board before but I really like the results it brings. Straight from a MacBook Air, nothing fancy, the DA8 sounds at least 8/10ths as good as it ever will. My dedicated Auraliti server brings it up to 9/10ths, I assume due to better power supply and regulation of the 5V line. Using $1500 worth of Audiophilleo AP1+PurePower driven by the Auraliti gets me the final 10/10, in a clear example of how costly it can be to chase that last bit of performance. [/size]
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[size=small] The other inputs are fine. They vary a little from one transport to the next, though not quite as much as the D18 did. I assume it's the proprietary buffer at play helping equalize things a bit, while the D18 used the built-in Sabre digital receiver alone. Toslink won't play higher than 96kHz reliably, which is pretty normal for most optical inputs.[/size]
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[size=small] Outputs sound mostly the same to me. The D18 was known for its variation between RCA and XLR outputs, almost giving the user two different sounding DACs from which to choose. The DA8 is far less variable, with both options being nearly identical. I think I prefer XLR due to a very slight perception of increased inner-detail, while RCA seems just a bit smoothed over in comparison. But this difference is so small that I could easily be imagining it. The rear panel XLR output impedance is less than 50 ohms which Yulong says makes cable choices less important. It also makes XLR suitable for driving higher impedance headphones directly, which I'll discuss later. Important note - Yulong says DO NOT use XLR to RCA adapters with this particular model. It won't properly ground the connection and thus degrade sound quality, and could even potentially damage the DA8. There's really no need to do so anyway since RCA sounds nearly identical, so just don't do it![/size]
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[size=small] Filters have a very subtle effect. As the names imply, I find "sharp" to sound just a hair more crisp and detailed, while "slow" is the more laid back of the two. But the difference is very small. Even smaller is the distinction between the 50kHz, 60kHz, and 70kHz filter options for DSD playback. Supposedly the higher numbers make the resulting sound a little brighter but I honestly can't hear a difference either way. Perhaps in a different system it would be more useful. What is more obvious is the "Jitter Eliminator" option. Leaving it off with a basic source like a laptop will result in a somewhat unfocused sound - not terrible, but activating the jitter reduction sounds noticeably better. Same goes for SPDIF sources. I tried an old Denon DVD-2200 as transport which is getting pretty long in the tooth, and was never really anything special to begin with. It sounded just halfway decent with Jitter Eliminator turned off, but actually quite good with Jitter Eliminator on. With very good transports, however, I end up leaving Jitter Eliminator off. It seems like it maybe restricts transparency just a tad, when being fed an ultra-clean signal from my Audiophilleo combo or even just the SOtM output of the Auraliti PK90. But it's definitely beneficial when using a more basic (and likely higher jitter) source. Yulong says turning the Jitter Eliminator off makes everything "softer" while leaving it on is more "punchy" and I generally agree.... but maybe with a low jitter source the Eliminator does more harm than good? I don't know, but again I'm happy to have options. [/size]
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[size=small] The headphone amp is quite good. Yulong says it's better than his dedicated A100 amp ($360), but not as good as the flagship Sabre A18 amp ($899). I happen to have both of those and I'd say that's a completely accurate description. The integrated amp is clean and smooth, with plenty of detail and a great sense of coherence. It's powerful enough to drive the LCD-2 or HE-500 with very satisfying results. I'd say it's better at driving low impedance cans than high impedance models, though it does a competent job with HD800 and T1 too. The amp section is a little too noisy for most of my custom IEMs though. It shows some background hiss, and there's not lot of travel for volume control. So really sensitive models like Westone ES5 just don't work very well. Others, like the somewhat difficult to drive Cosmic Ears BA4, do better, despite a tiny bit of remaining background noise. There are a few in my collection that actually work quite well, including the 70 ohm Earproof Atom and the Lear LCM-5 with the Sound Tuned Adapter which raises impedance to roughly 180 ohms. Those both play nicely with the DA8 amp, and based on that I'd guess the Heir Audio Tzar models would be equally good. Back to full sized headphones - I would not hesitate to recommend the DA8 amp section, especially for lower impedance headphones and brighter models that need a little taming. The DA8 is a great match for Audio Technicas, and would probably do well with Ultrasones too (I no longer have any to try). I prefer the built-in amp over the Yulong A100 and the Matrix M-Stage, for example, and it comes very close to the Nuforce HAP-100 ($595). The DAC section is good enough to justify adding a really high end external amp at some point, but it's still nice to have a very capable integrated section available. [/size]
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[size=small] It's worth noting that the DA8 can drive balanced headphones straight from the rear XLR outputs. This maneuver has long been done by owners of Lavry and Benchmark DACs, with generally positive results, though I haven't tried it with those for myself. Obviously one will need a balanced cable terminating in dual 3-pin XLR connections - a style I don't really care for. Talk about bulky.... all my balanced headphones use a single 4-pin XLR connection, so I contacted Ted at CablePro to build me a custom adapter made from his excellent "Freedom Series" cable - actually I needed the adapter for my upcoming review of the Firestone Audio Bobby balanced amp, but I figured it would work with this unit too.... I was wrong, as the DA8 required female to female adapters to get my CablePro adapter to fit. At that point it was even more bulky... but at least it worked.  [/size]
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[size=small] I tried the HD800, LCD-2, HE-500, and HE-400 in this special balanced configuration. I actually preferred the planar models from the front panel 1/4" jack - they had more drive that way, more immediacy and zing. Through the XLR outputs they seemed a bit "soft" and syrupy. At the time, I didn't know the impedance involved, but know that I know it makes complete sense. Although planar headphones are less concerned with output impedance compared to dynamic designs, 50 ohms is still high enough to result in a low damping factor. The front panel jack has no such issue. Having said that, the HD800 sounded very nice in balanced mode - in fact I think I prefer it to the actual headphone out. It too is more laid back than the already somewhat relaxed integrated amp, but with HD800 is works marvelously. Aside from the smoothness, the balanced HD800 seems more spacious and alive, with a broad and very deep soundstage. It's definitely worth trying if you have a balanced headphone. I suspect it would be very nice with the T1 as well, but I don't have a balanced cable on mine so I can't be sure. [/size]
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[size=small] Turning off the pre-amp and headphone stage gives a very slight hint of better sound. But only when used with a highly resolving amp in the $1K+ range. Maybe it's my imagination or placebo in action, but whatever it is I'll take it. It's not like pushing the button is difficult to do... I'm very thankful for the preamp and headphone stage, yet also thankful that they can be disabled. Best of both worlds. [/size]
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[size=small] COMPARISONS[/size]
[size=small] To switch things up a bit, I'm going to focus on how the DA8 stacks up against some tough competition. Most of these are DACs which I hold in very high regard, so the this is not an easy challenge in the least.[/size]
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[size=small] NuForce DAC-100 ($1,095): The DAC-100 has a more energetic, exciting sound signature, both as a DAC and in the (very enjoyable) built-in amp section. The presentation is less open and expansive, opting instead for a more lively, direct feel. Your preferences and music would determine which sound you like best, but I have a feeling more people would appreciate the DA8 as it would work better with a wide variety of music and gear. Even though the smoother DA8 seems like it would be a better pair for the somewhat bright HD800, the DAC-100 inexplicably ends up being the better match. Not sure how to explain that but there it is - though if I use the DA8 rear XLR option, it becomes more difficult to choose. The DA8 is very much the more refined sounding unit overall - it's got a more realistic treble presentation, more transparent mids, more layering and depth. Vocals especially come through more lifelike. The amp sections are quite different - Yulong sounds best with low impedance cans, and is smooth and inviting. NuForce is better with higher impedance models and is more lively. Generally, I think the DA8 amp is more useful. And yet, overall, the DAC-100 can be supremely fun to listen to. I'd call the Yulong a more mature sounding piece of audiophile gear, and not in a stodgy, boring, overly clinical way. In headphone terms it would be a HiFiMAN HE-500. The DAC-100 is more like a vintage Grado RS-1 where you absolutely love what it does in some cases, yet probably wouldn't prefer it to the HE-500 as an all around headphone for all types of music. I hope that analogy makes sense.[/size]
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[size=small] Firestone Audio Tobby ($1,099): These again are two very different sounding devices. The Firestone favors a more analytical, detailed approach, like an upgraded Yulong D100. As a fully balanced dual mono design it sounds best via the XLR outputs, and achieves best results via its very well done USB input. I'd say the DA8 is again the better DAC overall, with more features and better sound for a small price premium. And just like the Nuforce comparison, there will still be certain tastes or systems that do better with the Firestone despite the DA8 being generally superior. [/size]
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[size=small] Matrix X-Sabre ($1,099) and Anedio D2 ($1470): The X-Sabre is the real meat and potatoes of my comparisons. A lot of people have asked about which one I prefer. And it's a tough one to explain. Why? Because the Anedio throws a curve-ball into the comparison. It's like this: In my X-Sabre review, I stated the Anedio was on a higher level. That remains my firm opinion. And for the first time this side of a far higher price, I actually found something I (sometimes) enjoy more than the Anedio - the DA8. So it would logically follow that X-Sabre is inferior to the Yulong, right? Not so fast. I actually like the X-Sabre more. Weird, I know.[/size]
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[size=small] In an Escher-like situation, the DA8 is better than the Anedio which is better than the X-Sabre which is better than the DA8. In actuality all three are quite close in performance, and the differences were best noticed on my Stax setup. I like the Anedio better than the X-Sabre, at least in this particular system, because it captures more details, and has better transparency. The X-Sabre has a more "fun" sound but it just doesn't quite do as much for me in direct comparison. The X-Sabre is not all that different from the Yulong in general character, but they each have slightly different nuances which make them distinct. Compared to the Anedio, I find the DA8 to be just fun enough, yet still accurate enough, to be the preferred choice. This is somewhat shocking because the D2 has beat all comers until this point. I just find the DA8 to be a more musically satisfying with very little compromise in micro detail and no compromise at all in imaging or bass texture. It's very impressive. But this doesn't always apply to every system, and at times the Anedio is the best of all.[/size]
[size=small]  [/size]
[size=small] So why do I prefer the X-Sabre over the seemingly superior DA8? I'm not exactly sure why it goes that way - it just does. I ran all three simultaneously into my Stax SRA-12S and could switch back and forth on the fly, monitoring via the Stax SR-007mkII. Minor level matching was required to keep things fair. For the longest time I though I had a clear picture of the hierarchy: Yulong -> Anedio -> Matrix. But then I realized that I had mixed up my inputs, and I had to start over. After a lot of time spent, I determined that I do tend to favor the X-Sabre over the DA8. [/size]
[size=small]  [/size]
[size=small] The two are more similar than different. Both lean a bit towards the warm side, both have very expansive soundstaging, both are somewhat smooth. But I felt like the X-Sabre was a touch more involving. Yes, the DA8 may have been more organic and natural, but the X-Sabre was more exciting without going as far as being zingy up top. And I think that may be the answer - the Anedio is on the more analytical side in comparison, while the X-Sabre is more fun. DA8 is somewhat in the middle (though closer to the Matrix than the Anedio). For that reason, perhaps it stands out more as having a distinct, exciting sound signature. Call it more character... I really don't know. Eventually I had to move on - if I repeated this same test with a different amp and headphone, I may have obtained different results (and indeed when I casually use both models with the AURALiC Taurus and HD800, I think I like DA8 better, or when using the Violectric V200 and LCD-2 I like the Anedio best). So bottom line - the Matrix X-Sabre has potential to compete and even surpass the Yulong DA8 in some instances. Both are extremely nice and most people should be very satisfied with either. DA8 has more features and costs a bit more as a result. X-Sabre probably looks better, DA8 has more features, etc. The choice comes down more to system matching than individual competency. I'd love to proclaim my audiophile superiority in discerning the difference between any and all components, but in this case it's not so easy.[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] Yulong Sabre D18 ($699):  The DA8 is sort of an upgrade to the D18, but also a bit different. As the D100 mkII was to the original D100, so the DA8 is to the D18. But it goes in the opposite direction for tone. D100 was a little on the brighter, more analytical side, and the mkII upgrade brought it down a notch while maintaining high levels of clarity. The DA8 takes the ultra-smooth feel of the D18 and fleshes out the upper midrange and highs a bit more, with improved air and sparkle. A hint of that smoothness still remains, but it's more of a neutral presentation this time around. Unlike the D100 where mkII completely replaced the original, I'd say D18 and DA8 are different enough in concept and execution that they can coexist in the lineup together without causing any confusion. If you want warmer, smoother sound at a great price due to minimalist execution, go D18. If you want a mostly neutral, top level performer with all the bells and whistles, go DA8.[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] Esoteric D-07x ($4,650): No contest. The DA8 is clearly superior. I repeat - at less than one third the price, the Yulong DA8 is blatantly superior to the Esoteric D-07x. I have to qualify this by saying I have very little regard for this DAC, so it's not as big of a compliment as it initially seems. But it makes for a good headline, doesn't it? I remain a fan of Esoteric in general, but this is strike two in my book (the first strike being the original D-07 which I also found disappointing). [/size]
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[size=small]  [/size]
[size=small] PS Audio NuWave ($999): Again a DAC which I dislike, and again the DA8 is vastly superior in my humble opinion. If ever there was a night and day difference between two modern DACs in the same price range, this is it. The NuWave is just so bright, thin, and "digital" sounding in comparison to the far more refined DA8. Sorry to offend anyone who uses or loves the NuWave, but I just don't much care for it myself.[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] Gripes? Let me think about that.... I would have liked to see a BNC connection. It's a better interface than coaxial for a variety of reasons, and it's simple to convert BNC back to coax if needed. Also, I would have liked to hear dead silence when using sensitive IEMs with the integrated amp. Anedio and Resonessence Labs can do it, so the bar has been set. I realize the DA8 uses a discrete Class A topology which A) makes silence difficult, and B) makes full sized headphones sound great. But the fact remains the DA8 is not ideal as an all-in-one solution for IEM users. A remote control would have been nice too. Notice a trend here? All my gripes are petty and deal with features rather than sound. [/size]
[size=small]  [/size]
[size=small] I asked Yulong if there was anything "held back" on the DA8 - given a higher price, could he design a better device? He replied that no, the DA8 is as good as it can be, and is really only limited on the basis of size. A far larger enclosure would allow for a "marginal" increase in sound quality. The D8, which has been in development for a while, will be roughly 5 times the size of the DA8, and cost more too. As far we've been told thus far, the D8 will be a limited release, so the DA8 should still be considered the flagship Yulong DAC.[/size]
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[size=small]  [/size]
[size=small] CONCLUSION[/size]
[size=small] What else can I possibly say? This review has gone on way too long already. The Yulong DA8 is supremely capable, among the absolute best DACs I've yet heard, pricing be damned. The headphone amp is good enough to be a serious tool rather than a mere bonus feature, and all the other features add up to make it quite the compelling device. But don't be fooled - the heart of the DA8 is excellent sound quality, and all the features are just a bonus. It would stand on its own, and justify the price, even as a pure DAC with no extras. I'd happily put the DA8 up against any sanely priced DAC and expect it to have a good chance of coming out on top. Once again Yulong comes highly recommended. [/size]
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[size=small]  [/size]

 
 
 
[size=small]Not long ago, I covered an obscure DAP out of China called the HiFi ET MA9[/size][size=small]. As you can read in that review - and I highly recommend you do before proceeding - I found that device to sound exceptional, despite a few minor quirks of the user interface. At around $860 the MA9 is certainly not cheap, but worthy of serious consideration for those looking to own a reference caliber DAP. The sound is just that good.[/size]
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[size=small] As a small company, I'm sure the maker realizes that not many people can afford to lay out the better part of a thousand dollars on a portable device. Also, there is some tough competition in that area, like the iBasso DX100 for example. The company seems to have taken this to heart and has launched a new player called the MA8. At $500, it's still expensive, but significantly less so than its big brother, making it potentially attainable to a wider audience. The first difference between the two is the enclosure being changed to a copper-like hue, which kind of looks pink in pictures but in reality is metallic brownish/orange, and rather interesting to look at. The MA9 was available in dark green or black, so the two are not likely to be confused for one another.[/size]
[size=small]  [/size]
[size=small] A quick note - Rockbox support has been added for the MA9, which would make it an absolute beast of a player. As my review of that device indicates, the UI a bit simple and somewhat holds back the powerful hardware. Rockbox makes that complaint irrelevant. But I haven't been able to load it - apparently Windows XP or Vista are required, and all I have is Windows 7 or OSX. I assume the Rockbox support will quickly branch out to the MA8 as it mostly uses the same engine. I'm still working on finding someone who runs XP or Vista to flash my MA9 for me, so I'm in no rush.[/size]
[size=small]  [/size]
[size=small]
Wood presentation box, black this time (the MA9 was rosewood), mostly the same accessories
 

 
[/size]
[size=small]  [/size]
[size=small] DESIGN[/size]
[size=small] The MA8 starts with the same platform as the MA9. That means the same all metal enclosure, same display, same processor and UI. There are some improvements in the UI though - the VU meter is far superior this time around, refreshing quickly which makes it dance with fluidity rather than jumping along at just a few frames per second as the MA9 did. There's also a choice of digital filter options for the DAC, which make small but worthwhile changes to the sound.[/size]
[size=small]  [/size]
[size=small] Inside, the same modular design continues, but with different cards installed for DAC and amp sections. The original DAC board was rather ambitious for a DAP, and used a pair of classic PCM1704 R2R chips. The MA8 shifts focus to a more modern design based around the PCM1792, the current top DAC chip from Texas Instruments. It keeps the PCM2707 USB input which allows it to function as a USB DAC when connected to a computer. [/size]
[size=small]  [/size]
[size=small] The amplifier board is also different. The MA9 used a more complex structure, with each channel getting an OPA627 with dual BUF634 output buffers. The MA8 goes simpler by using a pair of AD797 opamps (one per channel) with an AD8397 as a buffer. It still has roughly the same output levels as the MA9. [/size]
[size=small]  [/size]
[size=small] The dual battery design remains, meaning no rail splitter or DC-DC conversion required. One battery supplies the positive rail, the other supplies the negative, and you're all set. Battery life is fairly good for a device of this caliber and in fact seems somewhat improved over the MA9, by a small amount. I'm not sure why that would be.[/size]
[size=small]  [/size]
[size=small] Like the MA9, this unit has analog volume control as well as digital. The analog volume wheel, deeply sunken in to the chassis to avoid accidental cranking, is used for headphone listening only, with the digital control set to max. For line out, which has a dedicated jack on the side (confusingly placed underneath the volume knob, which doesn't interact with it), the user may want to trim volume digitally as needed, so digital control comes in handy. There is still no digital output on board, and the device is still limited to 16-bit/48kHz or less due to the processor. [/size]
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[/size]
[size=small]  [/size]
[size=small] LISTENING[/size]
[size=small] Jumping right in, the MA8 sounds very different than the MA9. Gone is the ultra smooth, natural presentation, replaced by something more energetic and "high resolution". I'm not sure if I mean that in a derogatory way or not - but it's definitely different. MA9 was warm, and had exceptional bass, inviting mids, and smooth highs. MA8 could possibly be described as more neutral, but I'd also throw in the description "lit up" and "highly detailed". It's definitely a more modern sound that some people would prefer and others would not.[/size]
[size=small]  [/size]
[size=small] Interestingly, I'm not sure there really are more details to be had here. It's just the focus of the presentation that differs. I hear the same amount of plucking and fiddling from artists like Crooked Still and Abigail Washburn, but with the MA8 I'm really drawn to the leading edges which makes the detail more obvious. Same for horns, and actually most instruments now that I think about it. MA9 is more laid back with a macro-scale presentation, putting focus on the entire track rather than the individual components. But if I focus I can still hear just as much "stuff" happening here and there. In fact it seems more richly layered, like real music being played in the real world. The MA8 throws it in your face so it's more readily noticeable, and some people will clearly prefer that presentation. Personally I like the MA9 approach more.[/size]
[size=small]  [/size]
[size=small] The MA8 does sound good on a strictly technical level. It's got deep bass, great extension on the top end, and sounds mostly clear in the mids as well. The output impedance is low enough not to interact with even the most challenging multi-armature IEM, and the output is strong enough to drive most anything you'd want to lug with you (and even some decidedly non-portable cans as well). My chief complain is that the MA8 sounds somewhat bright and artificial at times. It does fine with reasonably smooth headphones such as VMODA M80 or 1964 Ears V3 (the latter being a particularly good match). But if I use something brighter such as the Cosmic Ears BA4, or Audio Technica W1000X, or even a JH13FP, things don't go as well. Low volumes are decent but as it climbs, grain and harshness start to show. I counteract this by using smooth and even potentially darker headphones - Heir Audio 8.A, Westone ES5, LCD-2. The MA8 drives planar headphones reasonably well - you probably wouldn't want this as your only source for LCD-2 or HE500, but in a pinch it sounds decent enough. HD650 is a better match - I actually enjoyed it very much, and the top end was far less bothersome than with the HD800. Notice anything about this trend? My preferences for the MA9 went in the exact opposite direction, where neutral to bright options sounded best. Here the tables have turned. [/size]
[size=small]  [/size]
[size=small] I ended up liking the MA9 over the MA8 for most music. The exception is classical, where I felt the MA8 did a different but roughly equal job. MA9 was better at showing the layers and depth in large orchestral works, but the MA8 had more pinpoint focus on solo piano and chamber music. I'd choose the player based on which headphones I was using, and in many cases I'd probably go MA8 over MA9. With other stuff like classic rock, metal, or various pop music, the MA9 suites my taste better than its little brother, at least most of the time. [/size]
[size=small]  [/size]
[size=small] At one point I had something of a good idea - what if it's the amp section letting down the DAC performance? I decided to stick with the line-out for a while, to see what I could figure out. And I'm glad I did - the line-out performance is quite good indeed, showing the headphone section to be something of a bottleneck for the DAC. Using budget portable amps like the TCG T-Box ($99) didn't really improve things - it merely shifted the issues to other areas. But something reasonably nice would show a definite improvement over the built in amp section. The Shonyun 306 ($180) for example, is not the best portable amp in the world, but it sounded far more listenable to my ears. I found it similarly clear and still slightly bright, but not annoyingly so. And it had more drive to work with difficult bigger cans. The Leckerton UHA-6S mkII ($279) sounded really good too - it showed off the grace of the DAC section which ends up being really quite nice overall. It's got a sense of fluidity that gets somewhat lost through the integrated amp, or maybe buried is the better word. [/size]
[size=small]  [/size]
[size=small] The line-out sound is good enough to where it isn't just for portable use. I paired it with a few desktop amps such as the NuForce HAP-100 and Firestone Bobby, and it was always enjoyable to hear. I'd say as a player it is easily in line with entry level CD players from NAD or the like. In fact I'd think one would need to pay $300+ for a new disc-based player that sounds this good, maybe as high as $400. I compared it directly to an old Denon DVD-2200 universal player which sold for roughly $600 a while back, and the MA8 was definitely the superior performer. It had more detail but was also more musically engaging, making the Denon sound a bit dull  and veiled in comparison. The PCM1792 is a fantastic DAC chip to work with, and the design here seems well thought out - it's a shame the amp section lets it down to some degree. Fortunately the MA8 uses the same modular design as the MA9, meaning a different amp card could be swapped in rather easily. I have not yet had a chance to try the card from my MA9 but that would potentially make for a killer combo.[/size]
[size=small]  [/size]
[size=small] As I mentioned, one of the few menu differences from the MA9 is the ability to choose a digital filter. The digital filter is built in to the DAC chip itself, unlike the MA9 which uses the DF1704 dedicated external filter. We get the choice of "Sharp" or "Slow" which doesn't drastically change the sound but does impart a subtlety which makes it worth messing with. The Sharp filter is clear and detailed, with nice extension and air. It's a bit narrow sounding though, like a more direct presentation. The Slow filter is more open and has believable depth to it, but changes the highs to make them a touch less airy. Which is odd because a lot of times the more air, the better the soundstage. But not this time. Anyway, I ended up preferring the filter set to Slow and left it that way whether using the headphone jack or the line out. But it's nice to have options.[/size]
[size=small]  [/size]
[size=small] Just like the MA9, the MA8 offers USB DAC capability. Plug it in to PC (or probably a Mac but I didn't try) and it switches to USB mode, allowing playback through its line-out or headphone jack. I revisited USB and found that I actually enjoy it much more this time around as compared to the MA9. In that device, playing via USB made everything blurry and fuzzy. The PCM1792 must have far better jitter rejection than the PCM1704, because this time I can't tell a difference between USB and internal memory playback. I still don't know that this is the most useful feature in the world, but since the device already has a USB port for data then it might as well have this added feature too. Why not?[/size]
[size=small]  [/size]
[size=small] CONCLUSION[/size]
[size=small] HiFi ET will never be a massive company. Their competition - HM801 and AK100 and DX100 and the like - is far more well known among headphone enthusiasts. And that's fine... just because others haven't heard of it, doesn't mean it can't deliver a rich experience. That's what HiFi ET aims for and on many accounts, it's what they achieve. [/size]
[size=small]  [/size]
[size=small] With the MA8, they aim to be more inclusive for people who can't afford a nearly $1K device. I am slightly disappointed by the amplifier section in the MA8, yet impressed by the rest of the device. As a player connected to external amplification, the MA8 is another story altogether - clear, extended, and mostly transparent, it represents a more modern Hi-Fi sound than the MA9, without overdoing it. If the company can tweak the amp section to better capture the character of the DAC without being too harsh, I think the MA8 would be a viable option for both home and portable use. As it stands, I have some reservations about giving it a clear recommendation. It's definitely one to watch though. [/size]

 
 
 
 
[size=small]Asus is a well known tech company. They make laptops, desktops, tablets, motherboards, video cards, and a few other odds and ends. Around here, they are most known for their highly regarded Xonar Essence series of sound cards. The Essence ST and STX are likely among the most widely used "entry-level audiophile" products out there - especially when you consider the massive number of PC gamers who eventually become interested in quality sound. John Atkinson covered the ST and STX at Stereophile[/size][size=small] a few years back and concluded they were definitely worth the investment. Though not perfect in sound or measurement (but what is?), they offered a very high amount of bang for the buck. [/size]
[size=small]  [/size]
[size=small] Several years later, we see Asus continuing their expansion into the audio market. The big news of last year was the Asus Xonar Essense One - a relatively expensive (compared to the ST/STX cards) stand-alone DAC with built in headphone amplifier and preamp capabilities. It's received plenty of industry praise including this review at InnerFidelity. Asus clearly has aspirations of being taken seriously by audiophiles and it seems to be going well thus far.[/size]
[size=small]  [/size]
[size=small] Yet there was a problem. Between the ~$200 price tag for the ST/STX, and the $599 starting price for the Essence One (climbing to $899 for the Muses Edition), there's a rather sizable gap. Asus needed something to fill that hole in their lineup. Enter the Essence STU. At $399, the STU fits square in the middle between the sound cards and the One - not just in pricing, but also in design and features. It shares elements of both designs and hopefully reaches a sweet spot between them. We'll see. Asus was kind enough to loan me a review model for what I believe is an exclusive HeadFi first-look. [/size]
[size=small]  [/size]
[size=small] DESIGN[/size]
[size=small] If the Essence STX is the base model sound card that works with PCI-Express, and the ST is the slightly improved version of the same in PCI only form, the U in "STU" logically stands for "USB". It departs from the internal sound card form factor of its siblings, instead living in an external enclosure. It's a good looking box - smartly designed, small and unobtrusive, able to lay flat or prop up on its side via an included stand mount. In size and shape it reminds me of a router - it should fit most anywhere. In general appearance, it has shades of vintage stereo receiver - a bit of retro design, on a much smaller scale of course. It does seem rather light in weight, which is in contrast to some other DACs with heavy-duty enclosures. But do those actually do anything for the sound? [/size]
[size=small]  [/size]
[size=small] The front panel is dominated by two volume knobs: one dedicated to headphones, the other for line out. Asus does provide an option for fixed, full volume line out via internal jumper. Aside from those knobs we get a 1/4" headphone jack, a power button, and a single button for cycling through the various inputs. The STU has dedicated LED indicators for each of its four inputs, as well as an LED showing "bitperfect" connection via USB. [/size]
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[/size]
[size=small]  [/size]
[size=small] Around back we find digital inputs in the form of optical and coaxial SPDIF as well as USB. Asus claims playback capabilities for all resolutions up to 24-bit/192kHz, which includes the asynchronous USB input. This is one of the few instances where the claim of 192kHz over Toslink actually proves true - most DACs have trouble locking on a signal over 96kHz, even from a pristine source. There's also a 1/8" jack labeled "AUX" for use with a smartphone or tablet. Lastly, we find a switch for selecting high or low gain on the headphone output. Asus doesn't specify exactly what the gain is for each setting but it seems like good mix of "low enough" and "high enough". This is actually an improvement over the Essence One, where the Muses Edition has gain set via internal jumper, and the base model has no gain adjustment options at all.[/size]
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[/size]
[size=small]  [/size]
[size=small] The STU internal componentry seems smartly executed. It starts with some of the stronger points of the ST/STX and builds off that solid platform. The design breaks down into separate sections for power, digital, and analog, and the analog portion is such that most companies would claim it as true balanced design. For their part, Asus uses the term "Fully Balanced Stereo Representation". We can argue all day about what constitutes a "true" balanced design (dual independent DAC chips?), but the STU only has single ended outputs, so it's not like Asus is trying to trick us. [/size]
[size=small]  [/size]
[size=small] SPDIF signals enter through a TI PCM9211 which is a new DIR I haven't seen used anywhere else yet. Specs are excellent, appearing to match the industry-leading Wolfson WM8805 at 50ps RMS period jitter. The PCM9211 also has an integrated analog to digital converter, which is used to digitize signals coming in from the AUX input. If I'm playing a song from my iPad via analog connection, I'm obviously not too concerned with maximum fidelity, so this extra conversion step doesn't seem like a problem to me. USB signals are handled by the C-Media CM6631A asynchronous chipset - note the "A" in that title. Schiit used the original CM6631 in their Bifrost and Gungnir USB boards, and it didn't support the 176.4kHz data rate. They now include the newer "A" version in their "Gen 2" USB boards. Asus also uses the same CM6631A in their Essence One.[/size]
[size=small]  [/size]
[size=small] Also on board is a Cirrus Logic CS2000, used for clock regeneration while attenuating jitter in the process. It's a hybrid analog and digital phase-locked loop, essentially a junior version of the "JET Technology" circuit used in the Weiss INT-202 FireWire interface ($1885). This works in conjunction with a trio of discrete clocks running at 12MHz, 45.1584MHz (for 44.1kHz signals and their multiples), and 49.152MHz (for 48kHz signals and their multiples). [/size]
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[size=small] Actual D to A conversion is handled by a PCM1792A, which is the current top of the line chip from Texas Instruments. I/V conversion is handled by a dedicated LME49720 opamp for each channel, while a single LM4562 opamp handles low-pass filtering. Fun fact about those particular opamps - they are identical. So why the two different names? National Semiconductor won all sorts of awards for the LM4562 when it first came out. They had a substantial marketing campaign built around it. A few years later, they came up with the idea of having a dedicated naming convention for high performance audio chips, using the special LME designator. But the LM4562 was already very well known and people specifically asked for it by name... so they couldn't get just get rid of it. Thus both parts co-exist, each with their own distinct datasheet containing identical information. Strange right? Yet I've seen designers and opamp rollers alike make the claim that each model sounds different, despite their similarities. I thought this was hogwash until I met someone who actually worked on the LM4562 project. He mentioned some minor variations in construction between each version of the opamp... the type of variations where nothing really should sound different, but nonetheless could. At least it gives a theoretical reason for why some people find them different, though I'm still not completely convinced. [/size]
[size=small]  [/size]
[size=small] Anyway, sorry for the tangent... getting back to the STU. As in their sound cards and the Essence One, the STU features socketed opamps in the important locations. They encourage users to experiment with rolling different opamps to see what the result is. In my listening section I'll discuss a few that I tried and the results I obtained. But I like the fact that the included opamps are already of high quality - if a person doesn't like messing with opamps, it certainly isn't required. There are also 3 more LM4562 opamps on board which are not socketed. These are used as buffer stages and supposedly don't influence the sound as much as the I/V or LPF section.[/size]
[size=small]  [/size]
[size=small] The headphone stage of the STU is based on the TI TPA6120A2. In this way it is similar to the ST/STX, and different from the Essence One which instead uses a pair of LME49600 opamps. Output impedance is 10 ohms which is common for devices using the TPA6120A2, as the specs for that chip recommend adding output resistors for stability. But some other devices like the iFI iCAN and Audinst HUD-mx2 use the same chip but achieve much lower output impedance while maintaining stability. So it's definitely possible, and I wish Asus had done the same. In this case the 10 ohm output impedance means the STU won't be ideal for most balanced armature based IEMs. Even some full size lower impedance headphones such as Grados will have audible frequency response interactions and less electrical damping than they otherwise could. On the plus side, Asus implements a DC servo on the headphone output to eliminate any power-on thump noises. It's defeatable via internal jumpers in case someone finds it to be a sonic compromise. It features a socketed OPA2134 opamp which can be swapped out for different flavors of sound. Options are good to have. [/size]
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[size=small] Other odds and ends: SNR (A-weighted) is listed as 120dB for the line out, 117dB for headphone out. THD+N (at 1kHz, A-weighted) is -108dB for line, -101dB for headphone. Full scale line out is the industry standard 2Vrms, while the headphone out can swing up to 7Vrms. As mentioned, headphone output impedance is 10 ohms, while line out is 100 ohms. Asus ships the STU with an outboard power supply that reminds me of the type used for a small laptop or netbook. It beats the typical "wall wart" style PSU included in some DAC in this price range, and the STU also has some dedicated power supply regulation on board. I love a fat toroid or R-core transformer as much as the next guy, but this solution seems to work well enough and helps keep the STU very compact. Asus does mention a possible upgrade to a linear PSU but it's not something they provide at this time, so you'd have to use a different brand. I didn't have anything to try so unfortunately I can't comment on this potential upgrade.[/size]
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[size=small] Power supply section on the left, digital in the middle, analog on the right:[/size]
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[size=small] Headphone section (towards the top of this pic:[/size]
[size=small]
 
 
USB receiver:

 
Toshiba TPC8107 MOSFET in power supply section:

 
cFeon EEPROM on the right, empty spot on the left where Cirrus CS2000 would be"

 
PCM9211 DIR:

 
PCM1792A DAC chip:

 
Analog output stage (I have Muses 02 opamps in there are time of pic):

 
Jumpers at the volume pot for line-out:

 
DC servo with socketed OPA2134:

 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] EQUIPMENT[/size]
[size=small] I used the following equipment to evaluate the Asus Xonar Essence STU.[/size]
[size=small]  [/size]
[size=small] Transports: Dell Inspiron 17R running Windows 7, Foobar2000 and Fidelizer, either direct through USB or else through an Audiophilleo AP1 with PurePower battery supply, Toshiba HD-A35[/size]
[size=small]  [/size]
[size=small] AMPs: AURALiC Taurus, Violectric V200, Icon Audio HP8 mkII, Yulong A100, Matrix M-Stage, Firestone Audio Bobby, Stax SRA-12S, Leckerton UHA-6S mkII[/size]
[size=small]  [/size]
[size=small] Headphones: Stax SR-007mkII, Sennheiser HD800, Denon D7000, V-MODA M-80, HiFiMAN HE-400, beyerdynamic T1, Westone ES5, Sensaphonics 3MAX, Cosmic Ears BA4, Heir Audio 4.A, Heir Audio 8.A, 1964 Ears V3[/size]
[size=small]  [/size]
[size=small] Power is handled by an APC S15 and a Yulong P18, all cables are Cabledyne Reference. The STU was burned in for well over 100 hours prior to critical listening. [/size]
[size=small]  [/size]
[size=small] Cabledyne Reference cables:[/size]
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LCD-2:

 
 

 
Thunderpants:

 
T1:

 
HD800

 
With Icon Audio HP8 mkII

 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] LISTENING[/size]
[size=small] My initial exposure to the STU was to use it in a realistic setup; the type that might be owned by the target demographic. To that end I used what I consider a "decent but nothing-spectacular" laptop, feeding the STU straight from USB. I plugged the V-MODA M-80 directly into the integrated headphone jack of the STU and got to work listening. I played some Mozart, some Metallica, some Miles, and some Michael Merenda, to cover most genre bases. And guess what? This setup sounded very respectable no matter what I threw at it. Good bass extension, clear mids, detailed treble with little harshness. Soundstage wasn't massive but it didn't feel overly constricted either. The STU seemed able to resolve complex passages well enough, and it had good tonal accuracy on the simple-yet-difficult-to-get-right stuff like piano or cymbals. Definitely a good start to my experience with this unit, and if I don't stray from the perspective of the target market, I find nothing to complain about.[/size]
[size=small]  [/size]
[size=small] However, since I'm accustomed to using more expensive equipment, something did in fact sound a little off about the STU. It wasn't a glaring fault, but I did feel the bass was a bit more loose and undefined as compared to my usual M-80 experience. To test my theory, I swapped over to the Leckerton UHA-6S mkII, a sub-$300 portable amp/DAC unit which should be in the same league as the STU in general terms. What resulted was a subtle reduction in clarity accompanied by an obvious improvement in bass definition. Then I had a lightbulb moment - I had forgotten about the output impedance issue. The M-80 impedance falls between 30 and 35 ohms. The Leckerton has an output impedance of less than 1, meaning no chance of interactions. The STU, with its 10 ohm output impedance, is not free of that issue, and I believe that's what I was hearing on the low end - a less than adequate damping factor. [/size]
[size=small]  [/size]
[size=small] To keep this in perspective - a "normal listener" (which I mean in the least condescending way possible) would probably not notice any issues whatsoever, unless maybe you set up an A/B comparison and specifically walked them through it. But without a reference point, the STU sounds great. And even with a knowledge of this small issue, I was still able to enjoy it well enough. [/size]
[size=small]  [/size]
[size=small] Next I switched headphones to see what worked and what didn't. The STU was able to drive the Sennheiser HD650 with authority, sounding very good for such a compact and relatively affordable all in one unit. The 300 ohm impedance of the HD650 is high enough to not be susceptible to the higher output impedance. I found I could comfortably use the low gain setting with the volume cranked high, or use the high gain setting with the volume knob turned lower. The HD650 is often called "dark" but from the STU it seemed nice and smooth without being overly veiled. I think I could be quite happy with this setup. [/size]
[size=small]  [/size]
[size=small] The STU also did quite well with the HiFiMAN HE-400. Despite a lower impedance, planar headphones seem far less affected in the way their dynamic counterparts can be. The HE-400 sounded clean, dynamic, full bodied, and was lots of fun, especially with rock and metal. The Asus had plenty of drive and bass extension was impressive. Once again, a combination I can highly recommend. [/size]
[size=small]  [/size]
[size=small] The Denon D7000 was good but a little sharp up top. Bass could be tighter as well, probably due to the output impedance mismatch, but the overall result remained mostly enjoyable. I'd say STU users would be more likely to own a D2000, maybe with some damping mods, and that could make a really nice pairing. I haven't heard the funny looking D7100 and its siblings so I can't comment on those.[/size]
[size=small]  [/size]
[size=small] The Audeze LCD-2 (latest version in bamboo) made a great pairing with the STU. There was plenty of headroom and the slightly lean character did nothing to stop the LCD-2 from having ferocious bass when called up to do so. Soundstage, not an extremely high point for the Audeze cans as compared to some of its competition, was reasonably spacious and well defined if not particularly a standout attribute. Clarity was high and overall timbre was very believable. Again, I could happily live with this combo as my main setup, even speaking as a snob who is used to far more expensive gear. [/size]
[size=small]  [/size]
[size=small] I then tried the 600 ohm beyerdynamic T1. It's a headphone I enjoy at times yet find merely decent at others, and it really has to do with system synergy. I tend to prefer it with a smoother amp such as the Violectric V200, and it sounds great with tube amps as well. I was surprised at how decent the T1 sounded driven straight from the STU. It sounded fairly enjoyable. And yet.... if I was used to something like an HD650, and got the T1 as my first example as a flagship headphone, I'd be somewhat disappointed with these results. Not because it sounds bad, but the price difference approaches $1,000, and I don't hear nearly $1,000 worth of improvement. It's a very inoffensive sound, clean and clear, but lacks a degree of body and soul. Apparently the STU just doesn't gel well with the admittedly picky T1 sound signature. It's not a power issue, as the STU has plenty of headroom... it's simply a signature mismatch. I've heard worse, but also much better with the T1. I do realize this is a somewhat unrealistic pairing though - the STU user would be far more likely to use a DT880 or T70 or one of those types. But I don't own any of those, so T1 is all I can speak for. [/size]
[size=small]  [/size]
[size=small] Next I tried some IEMs. I found that on low gain, the STU amp section is very good for IEMs, with no hiss and a clean background. Channel tracking is nearly perfect as well. Too bad the high output impedance causes unpredictable variations in the frequency response - if not for that, the STU would be perfect for IEMs. As it stands I got good results from some of them (1964 Ears V3, Cosmic Ears BA4), and not so good results with others (Lear LCM-5, Heir 4.A). IEMs based around dynamic drivers probably do better or at least perform more consistently. Again, this is one of those things where non-headphone nuts might not notice or care - I suspect the average user would still be very pleased with most of these results, despite my picky complaints.[/size]
[size=small]  [/size]
[size=small] I was able to determine that I like the amp section of the Leckerton UHA-6S mkII a bit more than the amp section in the STU. Even despite the impedance issues, the Leckerton seems more weighty on the bottom end, which anchors the performance and gives it a more complete feel. That's nothing to be ashamed of - the Leckerton is a killer little unit! On the flip side, as a DAC, the Asus is definitely superior. Faster, more articulate, bigger soundstage; basically a whole different class above, or maybe several classes. Based on this, I come to the conclusion that the Asus STU, like many integrated DAC/amp units, is a DAC first and an amp second - in contrast to the Leckerton which is primarily a portable amp, with the DAC feature as somewhat of a bonus. Which makes sense to me - home users are more likely to add a stand-alone amp down the road anyway, so it's logical for Asus to throw more resources at the DAC portion. [/size]
[size=small]  [/size]
[size=small] Having figured out that last bit of info, I went on to test the STU as a DAC only. Here it fared pretty well. Overall I'd characterize it as a "fast" sounding DAC, somewhat on the analytical side, with good detail retrieval and precise imaging. It does fall somewhat on the lean side, so it still requires a bit of care in system matching. I liked it with the Matrix M-Stage a lot more than I did with the Yulong A100 - the Matrix being more muscular while the A100 is maybe too much of a good thing, the results being too bright for my taste. Headphone matching was along the same lines - HD800 and T1 were not ideal pairings even when using a darker/smoother amp, and I imagine K701 (and variants) go the same way. But other headphones can be a very good match - HD650 chief among them, but also HE-400, LCD-2, and Thunderpants. I even ran the Asus in my Stax rig with an SR-007mkII, and the result was quite enjoyable. All this to say the Asus Essence STU is a worthwhile DAC when matched with the right associated gear. [/size]
[size=small]  [/size]
[size=small] A few other quick notes before I move on to comparisons:[/size]
[size=small]  [/size]
[size=small] *I ran the STU without enabling the DC servo. I never had issues with thumps or pops so it didn't seem necessary. But I'm glad the option is there just in case. I enabled it briefly and didn't notice any glaring SQ deficiencies, but I'd have to spend more time before definitively concluding that it doesn't have it's own sound. Swapping opamps in a headphone amp has been known to increase DC offset to the point where it becomes a problem, though this design doesn't power headphones directly from a socketed opamp so perhaps that doesn't apply. If I did feel the need to enable DC servo, I'd probably swap out the OPA2134 for an LM4562 just to match the rest of the system. If I didn't, it would probably bug me, whether or not it actually made a difference in sound. Being in the signal path, it is certainly conceivable that the OPA2134 could color the sound, and probably in a negative way - but it didn't seem like an obvious problem on quick listen. [/size]
[size=small]  [/size]
[size=small] *I couldn't tell any difference between the digital inputs. Further, I didn't notice differences between high-end and basic transports. I used a Toshiba HD DVD player (yes, early adopter here, still have a collection!) which is just a mediocre transport, and couldn't tell a bit of difference between it, or a $1500 Audiophilleo AP1 with PurePower, or basic USB from a laptop. This is a good thing because the STU target market probably doesn't want to bother with a really high end transport. [/size]
[size=small]  [/size]
[size=small] *I used the SD Card Player in my Resonessence Labs Invicta to test Toslink, and was impressed with the 192kHz playback capabilities. I've got lots of far more expensive DACs which can't do that. [/size]
[size=small]  [/size]
[size=small] *The device has some type of soft delay. Power on takes a few seconds, and switching inputs takes a bit of time too. This helps with the lack of pops and thumps. [/size]
[size=small]  [/size]
[size=small] *The front panel LEDs are not overly bright. They could be even more dim and I wouldn't complain, but this is a step in the right direction, especially compared to a lot of blazing LEDs found on other gear.[/size]
[size=small]  [/size]
[size=small] *The included stand, to prop the unit up on its side, actually works better than I thought. It's just plastic with a small bit of rubber lining in the right spots, so when I first opened the box I wasn't too impressed. But it seems to hold the STU tight enough to be sturdy even as I plug and unplug headphones. Downside? The DAC itself has feet on the bottom, so those will just be sticking out into space when running a vertical setup. It looks kind of awkward. I notice the promo pictures always show it from the "good side" to avoid this. Also, the DAC is on the lighter side, so heavy cabling could pull it when side mounting. Still, It's a nice feature for those with limited space. [/size]
[size=small]  [/size]
[size=small] *There's an internal jumper for bypassing the line-out volume control. This removes the potentiometer from the signal path and theoretically improves sound quality. Default setting is for volume control to be enabled. I went back and forth a few times and thought I maybe heard a very small difference. Certainly not night and day, and I wouldn't mind always running in variable mode if that's something I'd use at times. In fact, I did use it when running with a pair of active monitors, and it worked just as expected. Nice to have the option either way though.[/size]
[size=small]  [/size]
[size=small] COMPARISONS[/size]
[size=small] The STU lands in a somewhat unique price bracket. It costs more than a lot of the budget equipment out there, but less than most really "serious" audiophile gear. I don't have another $400 DAC on hand so you'll have to bear with these comparisons.[/size]
[size=small]  [/size]
[size=small] Audinst HUD-mx2 ($250): The Asus sounded more open and transparent than the little Audinst. It had a more believable soundstage too, with imaging being more precise. The Asus also sounded more even, no matter what input was used - the Audinst has a different tone over Toslink compared to USB, which I suppose could be considered a benefit if you like the option of a more relaxed signature. The Asus also has the advantage of accepting USB signals higher than 96kHz which is becoming more of a useful feature as more and more albums are released in the higher formats. [/size]
[size=small]  [/size]
[size=small] The DAC advantage is clear, but the amp section is less obvious. While the Asus was slightly cleaner and more airy, the Audinst was extremely similar. Both use the same TPA6120 for amplification so I suppose it makes sense that the sound isn't far off - but I've heard the TPA6120 sound very different in other designs (like my Kao Audio UD2C-HP), so it's not always the case. Audinst does some modification to the circuit resulting in a 2 ohm output impedance, making it far more suitable for low impedance headphones and especially multi-armature IEMs. [/size]
[size=small]  [/size]
[size=small] Ultimately the Asus is the superior product, but the Audinst remains a good value at the lower price. For someone on a tight budget I might recommend adding that cash to the headphone fund rather than buying the better DAC. Then again, someone with a higher quality headphone like HD650 will hear a very worthwhile improvement with the better DAC. [/size]
[size=small]  [/size]
[size=small] Parasound Zdac ($475): This is a very different sounding product compared to the Asus. Warmer, richer, more smooth and creamy, it's all about musicality rather than hyper-detail. It could be a much better choice or a far worse choice depending on your system and preferences. It adds XLR outputs but subtracts preamp functionality and USB connectivity beyond 96kHz. The headphone section uses the same TPA6120 with the same 10 ohm output impedance, so neither one is ideal for IEMs. Personally I'd choose the Zdac every time for headphones like the T1 and HD800. For an LCD-2 or HE-400, the Zdac is still good, but I'd give the edge to the Asus. They split the difference with the former flagship Sennheiser models, with Zdac loving the HD600 and Asus doing better with HD650 (though both are quite good either way). [/size]
[size=small]  [/size]
[size=small] In the end I think each DAC lines up well with the philosophy of their brand. Asus is a high-tech company and the STU excels at detail and accuracy, using a variety of advanced techniques to get there. Parsound, on the other hand, is a far more experienced audiophile firm, and really has the analog design expertise to pull off a musically compelling sound. A lot of it probably ties in with the power supply and analog stages rather than digital wizardry. Either of these units, when used in the right context, should give years of faithful service, and I can confidently recommend both. [/size]
[size=small]  [/size]
[size=small] Resonessence Labs Concero ($599): The Concero is truly a giant killer in my opinion - a tiny USB powered box that puts a lot of fancy audiophile DACs to shame, despite any price differences. The Asus doesn't have the same level of realism, which becomes especially noticeable with well-recorded classical. Concero is more transparent and clear, and reveals more layers in each track - assuming they exist in the first place. The Concero also has more "swing", while the STU comes off as a bit lighter in tone. [/size]
[size=small]  [/size]
[size=small] This comparison highlights the difficulty faced by Asus in trying to make waves in this market. There are just so many other exceptional choices, and there ends up being an ever smaller window in terms of pricing, where their offering can compete. In the case of the STU, I can see the argument - "should I spend $400 on the Asus or save another $200 and go for the Concero?" Yes, the Asus does have more features, so it's got that going for it, but the Concero is just tough competition based on pure SQ. So it really depends on what sort of device one is looking for - can you give up the larger selection of inputs and features for a distilled, high performance USB DAC? If yes, Concero, if no, STU. [/size]
[size=small]  [/size]
[size=small] Asus Xonar Essence One ($599): I was able to borrow the Essence One from a friend, in order to compare to its STU sibling. This was a stock unit rather than the Muses variation and my friend had never rolled opamps. To be honest, I don't think they sound all that different. The One seems more capable as a headphone amp, but as a pure DAC the differences are a lot smaller. Certainly smaller than ST versus Concero. I didn't get as much time to compare them as I would have liked, so I'm not making this a definitive proclamation at this point. But so far I'd say the STU might be the better buy if you intend to run an outboard amp and thus nullify that advantage. With the option of adding a linear power supply and better opamps down the road, a gradually upgraded STU would still cost less than the base model One. And the user wouldn't be paying for things like XLR outputs which they might never use. Makes sense to me. [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] OPAMP ROLLING[/size]
[size=small] Asus was kind enough to send along a few sets of opamps for my rolling adventures. I also had a few of my own, so I was able to get a good feel for the capabilities. Since it only takes 3 opamps, it's not that difficult or expensive to try. Compare that to the One which has 11 socketed opamps to mess with. I have to reiterate that the stock setup is very nice - some people might find it better than any of the variations I tried. So rolling is merely optional and not in any way required.[/size]
[size=small]  [/size]
[size=small] First I tried the Muses 01 (I refuse to type it in all caps like the company does....) which is used in the Essence One Muses Edition. This is a very expensive J-FET opamp - somewhere in the realm of $50 each, if you can even find them. I've never been completely blown away by this chip, despite the high price. But I have heard it sound pretty good, which ends up being the case here. It's got a squeaky clean, hyper detailed character to it, an extreme "Hi-Fi" sound that detail lovers would kill for. Soundstage is correspondingly large as well. In that respect it does bring the STU up to a higher level. The downside, in my humble opinion, is that it results in a somewhat unbalanced presentation. The STU was a bit on the brighter side already but it downright shimmers and gleams with the 01 installed. It therefore becomes too bright for my tastes unless paired with the warmest, smoothest amp and headphone combinations. Using the Violectric V200 with the LCD-2 works well enough but even then, I tire of the sound sooner than later and end up wishing for the original flavor to return. I can see how some people might like this result but I'd call it overpriced for what it is. [/size]
[size=small]  [/size]
[size=small] From there I went with the OPA2604 which is a notoriously picky opamp. It can sound really good in the right circumstances, but generally sounds bad when rolled into a circuit not specifically designed around it. That's exactly what happens here. Compared to stock, the sound is muddy and indistinct, yet still manages a thin, grainy feeling, all with a flat, two dimensional soundstage. This is definitely not an option I recommend.[/size]
[size=small]  [/size]
[size=small] After that experience I went to the tried and true OPA2134, as found in the DC servo. This is a workhorse opamp found in many applications, and generally sounds decent if not spectacular. It followed the same pattern in the STU - good resolution, nice bass extension, a little softer up top than the stock configuration, and not as detailed overall. This is a cheap opamp and might be a good alternative option for someone who finds stock a little too bright, though it comes at the expense of some definition and realism. Personally I like the original setup better - and I suspect there are better choices out there for a more musical presentation.[/size]
[size=small]  [/size]
[size=small] Finally I tried the Muses 02 bipolar opamps. Now that's more like it! I've never used this one before, but I find it to be a great match in the STU - better in a lot of ways (but not all) than the stock LME49720/LM4562. The best word to describe it is natural - it's warm, organic, yet still very detailed, placing the STU closer to the Resonessence Concero than any other opamp I tried. Bass impact finally makes a grand appearance, though I'd still never call the STU a bass monster. Top end has just the right amount of sparkle without going overboard. The only thing stopping it from being a clear upgrade all around is the soundstage, which is just slightly smaller than the stock configuration. It doesn't feel particularly restricting, but it's just not quite "there" in the same way as the original configuration. Overall though, I'd say the Muses 02 is a clear winner, and a major upgrade to the Asus Essence STU. For my tastes, this is an ideal combination, though of course there are many other opamps I have yet to try. AD797 would be a good idea, as would OPA627 on dual adapters for each spot, AD8610, OPA209, AD8397..... the list goes on, but I didn't have those handy so I have no idea how they would perform. And I can think of a dozen others which may be good candidates as well. The Muses 02 is spectacular, and even at $150 for the three of them it seems worth it to my ears, but you may be able to approach the same level for a lot less using other opamps. [/size]
[size=small]  [/size]
[size=small]
 
[/size]
[size=small]  [/size]
[size=small] RELATIVE VALUE?[/size]
[size=small] A quick note - my review loaner is an engineering sample which does not quite match the final configuration. Specifically, mine doesn't have the Cirrus CS2000 on board for reclocking. It looks like all the supporting hardware is there but the chip itself is absent. Astute readers will recall this being the case with the Essence STX as compared to the ST. People having experience with both cards describe a general increase in sound quality, specifically as it pertains to realism and imaging. The STX is reportedly somewhat hazy and indistinct in comparison to the ST, which I speculate is due to improved clocking performance. In any case, the implication is that I'm not quite getting the full experience from my particular STU, and retail versions should be improved by either a small amount or maybe even a large one.[/size]
[size=small]  [/size]
[size=small] Back to the comparisons - unfortunately I don't have access to a computer equipped with an ST or STX. But even if I did, I suspect there's enough variability in there to confuse matters. A gaming PC with a really nice PSU is going to have the advantage over a basic system with some voltage sag. But I did ask Asus for their thoughts on why the STU is superior. Their answers confirmed what I already thought, so here's a list:[/size]
[size=small]  [/size]
[size=small] 1) Asynchronous USB is a huge advantage over internal PCI or PCI-X interface. You might be familiar with the arguments for asynchronous versus adaptive USB modes? Well, the internal sound cards operate in the same way. Timing will not be as exact and thus jitter will not be as low. [/size]
[size=small]  [/size]
[size=small] 2) Better opamps by default. The LM4562 and LME49720 were popular options to be used with the ST and STX. The STU already has them. [/size]
[size=small]  [/size]
[size=small] 3) Gain selection for headphone use. This is critical when using a range of different headphones with different requirements.[/size]
[size=small]  [/size]
[size=small] 4) Mirrored PCB layout for lower cross-talk.[/size]
[size=small]  [/size]
[size=small] 5) Dedicated volume control, complete with jumper bypass option. This is a big one. With an internal sound card, all volume control must be done in the digital domain. Now, I've had good experience with digital volume control, and I don't find it as objectionable as some other reviewers. 32-bit implementations can be essentially transparent in my experience, and even 24-bit can be quite good - especially at higher volumes where less attenuation is called for. The STU is a 24-bit implementation which doesn't worry me so much. But how high do you normally run your volume levels? Maybe 50 percent? 75? Or far less when using sensitive headphones? I find myself at 30-40 percent quite often on my desktop system. With the ST and STX cards, that would result in a significant loss of resolution. The STU on the other hand uses a reasonably high quality Alpha brand potentiometer (similar to the one found in the Essence One) allowing for no loss of resolution. Of course, analog pots are not perfect, and I get the slightest bit of channel imbalance with IEMs (at extremely low levels - as in nearly silent - I hear one channel drop out before the other). And we can only assume some loss of transparency is taking place by even using a potentiometer at all, though I'd say it would still be less than digital attenuation in this case. [/size]
[size=small]  [/size]
[size=small] 6) Better components - the STU uses higher quality parts such as WIMA FKP2 capacitors where the ST/STX counterparts use some yellow (unknown to me) variety. It also has a more advanced power supply section, complete with DC-DC conversion and ultra-low dropout voltage regulation. [/size]
[size=small]  [/size]
[size=small] 7) Distance. The ST/STX units have dedicated shielding to keep out unwanted interference. But they still, by their very nature, are forced to live inside the PC case which is full of other components. The STU solves that problem - as an external device, it isn't subject to the same exposure. [/size]
[size=small]  [/size]
[size=small] 8) Options. It bears repeating once again that the STU has way more functionality than the internal soundcards. Gain adjustment, independent volume controls, selectable DC servo, etc. [/size]
[size=small]  [/size]
[size=small] 9) Lastly, and this is another big one for me - it gets rid of the PC requirement. Maybe this is obvious, but I feel to the need to expand on it. Yes, computer audio is growing very quickly, and I'd wager far more new audiophiles use computer-based systems rather than optical media. And yet, within the "computer audio" genre there is a growing subsection of users who don't necessarily want to use an actual desktop PC. Some people stream from their laptop - in fact based on the numbers there are more and more laptops and less desktops out there as each day passes. Others build dedicated small form factor machines running VortexBox. Some might even use a Blu-ray player or other network enabled media streamer for UPnP playback from a NAS. Others simply use a Squeezebox Touch or other affordable dedicated device. The point is - none of these situations allow for an internal sound card like the Essence ST. So Asus is wise to bring a device to market which can accommodate all of these scenarios. [/size]
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[size=small]  [/size]
[size=small] CONCLUSION [/size]
[size=small] The Asus Xonar Essence STU seems destined to become a popular product. I'm proud to have received an early prototype for review, and even more proud that Asus is reaching out to the HeadFi community for feedback. It's a tough place to start - they could easily have reviews done by various gaming and PC websites with little experience in terms of audiophile gear, likely resulting in rave reviews and awards. Instead they came to HeadFi where we know all about the tough competition in this segment. Asus answered all my technical questions but then stepped back and let me write whatever I want. For all they know, I'm writing a scathing critique and effectively killing some pre-release buzz before the product really launches. [/size]
[size=small]  [/size]
[size=small] Thankfully I didn't have to write such a review. The Essence STU is a very worthwhile device that definitely deserves to be heard. Yes, it competes in a very tough market filled with great equipment, and because of that it doesn't quite stand out in its field the way their ST/STX products did. But I find that it has enough sound quality and features to justify its existence, and I honestly can't think of anything else I'd recommend at the price. Spending a bit more will get you a different sound (Parasound Zdac, Yulong D100 mkII), possibly better for some systems but worse for others. You have to move up to $599 for the Resonessence Labs Concero before getting a significant improvement, and even then it comes at the expense of multiple features.[/size]
[size=small]  [/size]
[size=small] For it's large feature set, great sound quality, customization potential (opamps, linear PSU), and general good looks, I give the Asus Essence STU my recommendation. And remember - my review unit didn't have the full configuration yet. Adding the Cirrus reclocking chip may prove to be a minor improvement at best, or it could be significant. If that was the case the STU would be an even stronger value. Either way, it's definitely a product worth looking at. [/size]
[size=small]  [/size]
[size=small]
***UPDATE***
So it turns out there was some confusion regarding the CS2000 clockgen on my STU loaner. My unit actually does have the CS2000 on board:
 

 

 
It's not clearly labeled so I was unaware of it being there, and Asus thought they had sent me an early engineering sample that didn't have it. Turns out the "empty" spot on my loaner was a place where they considered putting some other reclocking chip, but decided against it. 
 
What does this mean to you, the reader? Probably not much. I guess there isn't some hidden performance potential waiting to be unlocked - what I heard was as good as it will get, which is still pretty darn impressive. I still definitely recommend the STU for what it is. 

[/size]

 
 
 
[size=small]The DAC market is clearly exploding. Seems like every week or so we hear of a new model being launched. Many of them look quite nice, with good specs and plenty of features. Some of them come from established brands like Benchmark, NuForce, Parasound, and PS Audio. Others come from relatively new, smaller (but growing!) companies like Matrix, Schiit, Yulong, and Resonessence Labs. Lots and lots of good choices can be had these days, and it's a great time to be in the market for new gear.[/size]
[size=small]  [/size]
[size=small] These new DACs tend to fall into certain categories. There's a big demand for "budget" gear, with numerous brands vying for your money in the $250-400 range, give or take a few hundred. There's even the little Schiit Modi for $99. On the other end of the spectrum, lots of new high-end models have launched within the past year, from the Auralic Vega to the Metrum Hex to the MSB Analog to Calyx Femto... I could go on and on. These multi-thousand-dollar units tend to be well received (for the most part). My attitude is that they had better be, considering the price. [/size]
[size=small]  [/size]
[size=small] Lately, my favorite market segment is the "mid-priced" range, which I define as being above five or six hundred dollars but below $2,000. In fact I might say $1,500 is a better cutoff point though it's hard to choose a specific number. Either way, I've been very pleased with this category. Performance here comes very close to the true high-end DACs for a fraction of their prices, and features are often very comprehensive in this range. I've recently reviewed the NuForce DAC-100 and the Matrix X-Sabre and really enjoyed both of them. Older models, still very good and worth attention, come from Anedio, Yulong, and Violectric among others. And I've not even scratched the surface of this category - I have yet to hear the Mytek Stereo192 DSD, Teac UD-501, Schiit Gugnir, or any number of other candidates. But here I am bringing up another one.[/size]
[size=small]  [/size]
[size=small] The subject of this review is the Firestone Audio Tobby which, at $1100, fits squarely into that "mid-priced" category. You may recall Firestone from their line of compact devices such as the Fubar and Spitfire. In the past they seemed to focus on small headphone amps and DACs, though they did have a few other things such as the Big Joe integrated amp, Mass preamp, Supplier PSU, and Bravo reclocker. All of these little units fit squarely in the budget category, and many of them were well respected around here. Recently Firestone seems to be moving upscale - this Tobby DAC, along with the matching Bobby balanced headphone amp ($799), are a whole different class of equipment. [/size]
[size=small]  [/size]
[size=small] DESIGN[/size]
[size=small] As viewed from the front panel, the Tobby is very obviously a DAC. It's got no headphone jack or volume knob - this is a pure DAC with no added functionality. The unit measures roughly 9 inches wide, 8 inches deep, and 2.5 inches tall, and weighs approximately 5 pounds give or take. Build quality is on the high side and brings to mind the Yulong Audio D100, with the brushed aluminum enclosure in black and a thick silver faceplate. It's not quite as substantial as the solid CNC machined Matrix X-Sabre, but it's definitely on par with others in this price class. [/size]
[size=small]  [/size]
[size=small] The front panel is dominated by small buttons and LED lights. On the right side is a bank of four buttons - Source, Resample, Bit, and Pass. Source obviously toggles from one input to the next. Resample is interesting as it engages the upsampling feature but doesn't require integer multiples like nearly all other DACs do. I'll discuss that more later. Bit engages word length padding to 24-bits. Pass is short for passthrough which is just like it sounds, allowing the signal to pass through at its native rate. The left side of the panel has LED indicators keeping track of what the machine is doing. It's all pretty self explanatory. The left side LEDs help you keep track of which options are being used, in a rather bright fashion. [/size]
[size=small]  [/size]
[size=small] Around back we find a good amount of connectivity: USB, coaxial, Toslink, and AES/EBU inputs all support up to 24-bit/192kHz signals. Outputs come in RCA as well as XLR for balanced operation. There is a standard IEC cable receptacle and the unit is marked for 115V operation though it looks as if that can easily be switched inside the case. [/size]
[size=small]  [/size]
[size=small] But all this explaining is boring for you to read, and frankly, it's not very fun to write either. So let's go on a journey with pictures to examine the rest of the design.[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] The enclosure has a nice system using "rails" to connect the top and bottom parts together[/size]
[size=small]
 
 
Faceplate

 
Right side

 
Left side

 
Venting (it doesn't get hot at all though)

 
Input section

 
Output section

 
I believe voltage is adjustable internally, despite what the label says

 
Bottom feet

 
Another view of the feet in action, pardon the dust

 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] Internally there's a decent amount going on here. The USB section uses the XMOS chipset in what appears to be a proprietary implementation - it looks very different from the Stello U3 or Matrix X-Sabre or several other XMOS-based designs I have here. But it does still use the SMSC USB3343 USB transceiver which is called for in the XMOS reference board. SPDIF inputs are handled by the AKM4113 and all inputs pass through an SRC4193 asynchronous sample rate converter. Firestone must have preferred using the AKM digital receiver paired with the stand-alone ASRC chip rather than using the SRC4392 which is a combined ASRC and DIR package.[/size]
[size=small]  [/size]
[size=small] AKM DIR and TI sample rate converter[/size]
[size=small]
 
USB section with the XMOS chip has a discrete 26mHz clock for the transceiver function
but receives 44.1 and 48kHz clocking via the multiclock generator which I'll discuss shortly
 

 
SMSC USB transceiver is the new USB3343 model 

 
 
[/size]
[size=small]  [/size]
[size=small] Also on board is a TI PLL1707 which uses a 27MHz reference clock and generates up to four independent system clocks as needed by the system. This is fairly different - I've never seen it used before in any of my audio gear. The datasheet indicates a 50ps RMS jitter figure which is slightly lower than that of the AKM DIR (70ps), but nowhere near as low as the better oscillators from Crystek and others. Those tend to be rated in the single digits or fractions of a digit. How does this affect the overall jitter spec of the system? I don't know, as Firestone doesn't release that info. To make matters even more confusing there's also a Xilinx FPGA which is probably used for further jitter reduction among other things. [/size]
[size=small]  [/size]
[size=small]
Xilinx FPGA

 
PLL1707 clock generator, as you can see it ties in to the FGPA


 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] The Tobby is a fully balanced, dual-mono design. That means aside from the input stage, it essentially has two of everything: dual PCM1794 DACs, mirrored sets of capacitors, separate stages for I/V conversion and LPF each using a trio of socketed OPA2604 opamps, a relay on each XLR jack, etc. Both channels share a single largish toroidal transformer but have separate regulation stages from there on out. Conversion from balanced to single ended is done at the very last stage, handled by another OPA2604 and a separate relay. [/size]
[size=small]  [/size]
[size=small] View from rear[/size]
[size=small]
 
View from front

 
Can you spot the parallel dual-mono signal path?

 
Ring Core brand Toroid

 
Again, mirrored for each channel

 
 

 
PCM1794, the current top of the line Burr Brown DAC (along with sibling PCM1792)

 
Output stage with socketed opamps

 
Relays on the outputs, single ended conversion in the middle

 
 
One last interesting bit - the power supply has an AC to DC converter which puts out a 5Vdc signal. I'm not quite sure about the implications. Firestone tells me it is used to power the various microcontroller chips on board, and allows for extremely low power consumption in standby mode. I thought it might also be used to power the USB section but Firestone seemed to indicate that was not the case. Yet due to the slight language barrier when it comes to technical discussions, I can't be sure either way. 
 
 

 
 
 
 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] On DSD - I asked Firestone about DSD playback and they advised it was something they are looking in to. I'm not sure if that means this unit could be updated down the line to accept DSD signals, or if they would need to release an updated model. From what I can tell, the Tobby is theoretically capable of handling DSD. All the pieces are in place - the XMOS USB input can definitely handle it, and the PCM1794 DAC chips may or may not be capable as well - the PCM1794 is simply the hardware controlled version of the PCM1792, but the spec sheet doesn't list DSD while the PCM1792 does. Interesting. The real limiting factor could be the ASRC reclocking stage which definitely isn't equipped to handle DSD streams, but it may be possible to configure a true "pass through" for DSD signals. In any case, this is all speculation at the moment. I wouldn't buy the Tobby expecting DSD to come in the near future. But it would be a nice bonus if it did show up.[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] EQUIPMENT[/size]
[size=small] This is the equipment I used to evaluate the Firestone Tobby DAC:[/size]
[size=small]  [/size]
[size=small] Transports: Cambridge 740C, Auraliti PK90 USB with NuForce LPS-1 linear power supply, Acer Aspire netbook, Audiophilleo AP1 with PurePower [/size]
[size=small]  [/size]
[size=small] Amps: Firestone Bobby, Violectric V200, Auralic Taurus, Icon Audio HP8 MkII, Yulong Sabre A18, Analog Design Labs Svetlana 2, Yulong A100, Stax SRA-12S[/size]
[size=small]  [/size]
[size=small] Headphones: Stax SR-007mkII, Sennheiser HD800, HiFiMAN HE-500, beyerdynamic T1, Audeze LCD-2.2, Thunderpants, JH Audio JH13FP, Heir Audio 8.A, Westone ES5, Frogbeats C4, Lear LCM-5, Cosmic Ears BA4[/size]
[size=small]  [/size]
[size=small] Power Conditioning: PS Audio P3 Power Plant, Yulong Sabre P18[/size]
[size=small]  [/size]
[size=small] Cables: Cabledyne Reference AC cables, Cabledyne Reference Silver XLR and RCA interconnects, Cabledyne Reference Silver SPDIF, Charleston Cable Company Auric USB, Headphone cables from Charleston Cable Company and Toxic Cables[/size]
[size=small]  [/size]
[size=small] Speaker Setup: JF Digital HDM-03S music server, NuForce HAP-100 preamp, NuForce STA-100 amp, Sjofn (the clue) monitor speakers on Sanus NF30 Stands, Charleston Cable Company AC cables/interconnects/speaker cables[/size]
[size=small]  [/size]
[size=small] I let the Tobby burn in for well over 100 hours prior to doing any serious listening.[/size]
[size=small]  [/size]
[size=small]  
 
Auralic Taurus

 
Lots of Cabledyne Reference cables

 
Stax, Thunderpants, HE-400

 
T1, LCD-2

 
HD800 with Toxic Cables Scorpion balanced cable, Icon Audio HP8

 
Firestone Bobby 

 
[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] LISTENING[/size]
[size=small] The Tobby immediately stuck me as a neutral yet slightly analytical DAC. And I mean that in the nicest possible way. Clarity was excellent, leading edges were very defined, and the whole presentation seemed nicely detailed and transparent. After months of listening and rigorous A/B comparisons with other high quality DACs, that general description still applies. [/size]
[size=small]  [/size]
[size=small] First off - let's be perfectly clear: this is not a bright DAC. It's not thin either. Sure, compared to some warmer and more lush sounding designs, the Tobby might come off as being a bit light in the deeper bass regions, or as having a detail oriented sound as opposed to a more flowing and breezy presentation. But I wouldn't characterize the Tobby as being objectively bright by itself. It's largely neutral overall with just a slight focus on speed and accuracy. [/size]
[size=small]  [/size]
[size=small] To help clarify, I'll throw out some words that do apply to the Tobby - Airy. Effortless. Fast. Clean. Spacious. Tonally Accurate (OK that's two words, sorry!). Some words that don't apply to the Tobby - Brittle. Shrill. Harsh. Cold. Again, I can't stress enough how this is a mild flavor rather than a huge coloration. Consider it a bit of character in an otherwise neutral DAC. And while this flavor may be the deciding factor for some people choosing (or not choosing) the Tobby over a competing model, it isn't an overwhelming characteristic.[/size]
[size=small]  [/size]
[size=small] It's probably best to get into some musical examples and direct comparisons. I really love guitars through this DAC - from John Fahey to Sungha Jung, I'd say the Tobby is perfect for this type of music. The transients are strikingly clear, and it really feels like it couldn't get much better - assuming of course that the rest of the chain is up to the task. When I use my Icon Audio HP8 single ended triode amp and the Sennheiser HD800, it seemingly goes beyond a "clear window" situation and is more like "they are in the same room as me". Pretty nice for an $1100 unit - that's certainly not cheap, but in the grand scheme of things it isn't super expensive either. [/size]
[size=small]  [/size]
[size=small] I also really dig the Tobby with classical music. The soundstage is expansive, the imaging tight and accurate, the micro-details plentiful. It's pretty much everything you could ask for in a DAC at this price. I played a wide variety of music from Aaron Copland to Zoe Keating and everyone in between - Hayden and Shostakovich, Holst and Wagner, it all sounded very immersive. Some potentially bright recordings like the XRCD release of Albaniz: Suite Espanola come across as being just shy of too bright at times. It wouldn't be a stretch to push it over the edge with the wrong amp and/or headphones. But in most cases it stayed well controlled and sounded very convincing.[/size]
[size=small]  [/size]
[size=small] Switching to other types of music, I found that I enjoy some rock and metal more than others. The Tobby excels with technical metal and that sort of thing. I'm not a fan of the ultra-specific labels for each sub-genre - sludge metal versus doom metal versus post-thrash groove metal - but I am a fan of metal in general, and the Tobby seems well suited for a good portion of it. Bands with a more technical sound and reasonably high recording quality (think Meshuggah for example) sound excellent with a Tobby-based system. Older Metallica and Slayer and Megadeath sounds great as well. The Tobby gives special insight into details like cymbal decay without over-analyzing, and still maintains a good sense of rhythm and drive. On the other hand, it's ruthless on some recordings. For example, I have a hard time with Mastodon's Leviathan, which is an album I love but find requires a more sympathetic pairing. Also some older metal such as King Diamond is a bit cold sounding and the Tobby certainly doesn't warm it up. That same experience translates to a lot of classic rock as well - it sounds very accurate and clean, but could maybe use a little more drive. Or maybe not, depending on your preferences. [/size]
[size=small]  [/size]
[size=small] Let's talk synergy for a minute. There is some gear that I'd consider bright or harsh (or both), at least under certain conditions. Here's a partial list broken down by category:[/size]
[size=small]  [/size]
[size=small] CD Players/DACs: Cambridge 740C, Yulong D100 (original version), Benchmark DAC 1, Antelope Zodiac, Audiolab M-DAC, PS Audio NuWave[/size]
[size=small]  [/size]
[size=small] Amps: Gilmore GS-1, Yulong A100, Music Hall ph25.2, NuForce HDP (amp section), Meier Concerto[/size]
[size=small]  [/size]
[size=small] Headphones: Sennheiser HD800, AKG K701 and variants, lots of models from beyerdynamic, most Grados, Sony SA-5000, Etymotic ER4S[/size]
[size=small]  [/size]
[size=small] While assembling a system, I probably wouldn't want to use more than two components off this list. So for example if I used the Yulong D100 DAC paired with the Gilmore GS-1 - both excellent products on their own - I'd rather round out the system with my LCD-2 or Thunderpants or HE-500 rather than anything off the above headphone list. Or when I play CDs with the Cambridge 740C and listen with the HD800 or T1, I prefer a warmer amp in the chain, be it tube or solid state. Hopefully you get the picture. The Firestone Tobby would fit in to the list above - not as the worst offender mind you, but I still don't love it with the Yulong A100 and the HD800 - there really can be too much of a good thing, and that combo just focuses too much on details rather than musical flow. But when I pair it with my slightly warm Violectric V200, or the Yulong Sabre A18, or the Icon Audio HP8, or the matching Firestone Bobby balanced amp, good things happen. Spoiler alert - the Bobby is a very nice sounding and neutral amp, review coming soon at InnerFidelity. [/size]
[size=small]  [/size]
[size=small] I listened on my speaker setup as outlined above. It's a nice system but my (untreated) room is clearly the biggest limitation. Still, I really liked what the Tobby did for it. Before inserting the Tobby into the chain, I had been using the analog outs of my JF Digitial HDM-03S music server. That device is no slouch - overbuilt power supply, dual Wolfson WM8741 DACs, adjustable digital filters, quality opamps in a well-designed output stage. But using it as a transport to feed the Tobby DAC brought a more lively, focused presentation, with no loss in dynamics. My Sjofn speakers have a really smooth top end but are still very capable of revealing fine details and the Tobby really brought them to life in that area. Midrange seemed to blossom too, and soundstage was equally large but became more precise. And with no real downsides to speak of. [/size]
[size=small]  [/size]
[size=small] In terms of inputs and outputs: based on the design, I was worried the RCA outputs would be very compromised in comparison to the balanced outs. The extra stage for single-ended conversion seems to have been well implemented, so it's not a major downgrade. While I do still find balanced mode brings out the most of this unit, the RCA connection is not far behind. There's a small penalty to be paid in terms of transparency, but the general sound signature doesn't change. I've heard units like this where single-ended mode takes a hit in low frequency extension and thus causes the unit to sound brighter overall. The Tobby would not do well if that were the case - thankfully it isn't. Ultimately I'd say users limited to RCA inputs on their amp should still find Tobby to be a compelling choice. If they later upgrade to a balanced amp, it will just be that much better.[/size]
[size=small]  [/size]
[size=small] For inputs, I felt like USB was generally superior to the other options. It didn't seem to care if I used a basic laptop, or my Auraliti PK90 with the high-end SOtM USB card, it always sounded the same to me. This shows the Tobby as being very non-source dependent - at least in terms of USB - which is a good thing for a lot of users. Less jumping through hoops to extract the best sound. I tried my Audiophilleo AP1 with PurePower on the coaxial input and was able to just match native USB performance, but not exceed it. Using a Cambridge 740C as transport netted a slight loss of dynamics and flattened out the soundstage for a less engaging performance. Apparently there's still a bit of source dependence when it comes to non-USB inputs. Toslink and AES/EBU sounded fine but I don't have a lot of devices to try those with so I can't comment further. Bottom line is that most users will connect over USB and Firestone rewards them with the best sound this DAC is capable of. [/size]
[size=small]  [/size]
[size=small] Lastly, we should talk about the resampling options. Most DACs automatically apply their upsampling, bringing the sample rate up to whatever frequency they feel is best in their particular design (it's usually somewhere between 90kHz and 192kHz, though not always). Occasionally we get the option of bypassing that upsampling. Rarer still, but sometimes available, is the option to choose upsampling - a 48kHz signal can stay native or else go to 96kHz or 192kHz. The Tobby goes a step further to become the most "configurable" DAC I've yet experienced. It allows basically any signal to be brought to nearly any sample rate or bit depth. Have a 16-bit/48kHz track and want to use the "traditional" rate of 24-bit/192kHz? You certainly can. But you can also keep it at 16-bit if you want, or use a non-integer sample rate like 88.2kHz. Want to downsample a 96kHz track to 48kHz or even 44.1kHz? No problem. The sonic differences between all of these are surprisingly small. Though my brain was telling me these wacky non-standard upsamples or downsamples should sound bad, my ears had a hard time telling them apart. Apparently the FPGA plus ASRC plus multiclock generator makes this less of an issue than I would have anticipated. Sometimes I thought I had figured out a pattern where certain sample rates sound this way or that way.... but then a counter example would present itself and I'd be back to square one. In the end I mostly used the "typical" options just so I could relax, stop focusing on any possible issues, and enjoy the music. Perhaps more time spent with the Tobby as my only DAC would help me get to the bottom of this phenomenon. [/size]
[size=small]  [/size]
[size=small] Keep in mind that I used the stock OPA2604 opamps for this evaluation. Firestone had the insight to make all seven opamps socketed which means they can be swapped out at your leisure. Due to the balanced design you would always want the left and right side to mirror one another, so at least six of the same opamps should probably be used. That last opamp, used for single ended output, could probably be different without causing any trouble. I very briefly auditioned the Tobby with a few other opamps - the usual suspects like AD797, LM4562, and LME49720, and it did hint at being susceptible to changes in the sound. I thought I heard some things I liked and some other areas that I didn't. But I didn't have time to explore this in depth - even if I had time, I mostly have just a few of each opamp rather than six. This again is one of those areas where a long term owner would be a better judge than even the most thorough reviewer. All I can do is point out how the OPA2604 is generally considered a quality opamp, and leaving the door open to further rolling is a wise move on the part of Firestone. [/size]
[size=small]  [/size]
[size=small] COMPARISONS[/size]
[size=small] The Firestone Tobby, at $1100, is priced right in the middle of some very strong competition. Let's take a look at a few to see how it compares.[/size]
[size=small]  [/size]
[size=small] Yulong Sabre D18 ($699): The D18 is kind of similar to the Tobby in that it has a mild coloration to it. But they go in opposite directions, with the D18 being on the warm and smooth side while Tobby is slightly on the quick and detailed side. I feel like the Tobby extracts more fine detail, while the D18 better captures the flow of the music. Both are quite good and I could happily live with either - the difference comes down to system synergy. With a potentially edgy system, using a neutral or brighter amp with the beyer T1 or an Audio Technica W1000X or Etymotic ER4S, I might prefer the D18 to smooth things over a bit. But if I had an LCD-2 or HE-400 or Heir 8.A, all on the warmer side, I would rather have the Tobby in there digging out the maximum amount of detail. [/size]
[size=small]  [/size]
[size=small] Both of these DACs sound better from the balanced outputs than the RCA outs, but the difference is smaller with the Tobby. Interestingly, both DACs present a similarly large soundstage, despite their differences in character. The Yulong initially seems to have a major price advantage, but that gets reduced to some degree when you factor in a high quality USB to SPDIF solution (D18 has no USB input). Tobby already has USB covered - quite well in fact. Ultimately these are both very nice DACs that reach for very different sound signatures. The one that you like best will be determined by your system and your preferences.[/size]
[size=small]  [/size]
[size=small] Matrix X-Sabre ($1100): The X-Sabre is a beast of a DAC. It's got all the playback capabilities you could ever ask for with DSD and DXD support over USB. It's got extreme build quality that frankly puts most competitors to shame. And those cool blue front panel LEDs are so much more well done than the blazing lights on the Tobby. In terms of sound though, the Tobby again offers a fresh perspective that's different enough to be worthwhile. I end up liking the Tobby more when used in my speaker rig, and the X-Sabre more when used with most (but not all) of my headphone gear. [/size]
[size=small]  [/size]
[size=small] The X-Sabre has a beguiling midrange presentation that makes the Tobby seem a little lifeless in comparison. It's one of those A/B things where you don't hear any deficiency until you make the direct comparison. After the comparison, going back to normal listening, the deficiency disappears. Weird. As a counterpunch, the Tobby makes the X-Sabre seem a little slow and veiled in the upper registers, again only during direct comparisons. This is not a problem - and actually sometimes welcome - with lesser recordings, but with "audiophile" quality music it becomes a clear benefit for the Firestone unit. And again, after A/B comparisons, the X-Sabre doesn't sound veiled in the least. Funny how that works. [/size]
[size=small]  [/size]
[size=small] Both units share their USB superiority compared to other inputs. Clearly both companies recognize their core audience and the likelihood that USB will be the primary source for these DACs. While the Tobby sounds best via XLR output, the X-Sabre is equally adept through its RCA outs. So that's something to consider. Ultimately, and I realize this sounds like a cop out: these units will each appeal to a different user... my preferences lean more toward the X-Sabre type signature in general but I recognize that a large contingency of folks exist who would be happier with the Tobby instead. [/size]
[size=small]  [/size]
[size=small] NuForce DAC-100 ($1,095): The DAC-100 is very different animal. While the Tobby, like the X-Sabre, is a pure DAC, the NuForce is a DAC, preamp with remote, and headphone amp all rolled into one compact box. So in terms of functionality it has a big lead. The DAC-100 is limited to single-ended outputs though, which could be a disadvantage for some users. [/size]
[size=small]  [/size]
[size=small] The Tobby and the DAC-100 both have a lively top end that manages to not overdo it. But they go about their presentation in different ways. The Tobby is more elegant, sophisticated, "pretty" sounding for lack of a better word. It's got clean, tight bass that always maintains composure no matter how hard it hits. One gets the sense that Firestone engineers value a clean sound with a sense of restraint, and deliberately made sure their device would never give loose, sloppy bass. The DAC-100 is more muscular, with more drive and gusto. It's got a sense of excitement and dynamics, and it certainly doesn't hold back when it comes to low frequencies. The old school audiophile in me says this difference in bass presentation is predictable by glancing at the power supplies, and simply adding up the capacitance. But I've heard my little Violectric V800 equal or surpass the Audio GD Reference 7 in this area, the latter having a massively overbuild power supply, so I no longer think that approach is always the correct one. Regardless, once again the two units appeal to different users. In cheesy audiophile terms, the Tobby is more "effervescent", the DAC-100 more "bold". They compete well with one another and make it that much hard to choose a clear winner.[/size]
[size=small]  [/size]
[size=small] PS Audio NuWave ($999): To my ears, the Tobby is everything the NuWave tries to be, but fails. It's got a similar tonality overall but with less sharpness in the upper mids and highs, more believable top-end extension and air, and far more satisfying low frequency extension. I'm starting to think the NuWave I have on hand might be faulty.... but I've chatted with a few other users who hear it just the way I do. Some people on the forums really enjoy it but to me it seems less a case of sound signature preference and more a case of general capabilities. The Tobby just sounds better, cleaner, more accurate, more focused, without being annoying. If I was Firestone Audio I'd bring a NuWave to every show and meet I attended, and allow people to A/B them directly.[/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] I could go on and on, but I don't think it's necessary. Hopefully you get the point by now - Firestone clearly had a specific sound in mind for this unit, and I think they've achieved what they set out to do. As a result they end up with a great sounding DAC that has enough broad appeal where most people should like it well enough, but enough of a specific character where some people will really love it. [/size]
[size=small]  [/size]
[size=small]  [/size]
[size=small] CONCLUSION[/size]
[size=small] Has Firestone Audio shown themselves worthy of selling gear in the ~$1k price range? Based on my observations of the Tobby DAC and Bobby amp, I'd say yes. Rather enthusiastically at that. The Tobby is well designed, smartly executed, and ultimately sounds great. It doesn't blow away fellow competitors in the price range but neither is it blown away, instead offering a worthwhile counterpoint to some of those smoother, warmer models which give less focus on detail. For me, the Tobby brings back memories of the Benchmark DAC 1 - the good memories, which at the time were always tempered by fatigue. The Tobby manages similar levels of detail but to my ears sounds less grating in the process. [/size]
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[size=small] This is a truly enjoyable DAC no matter how you slice it. Even in a worst case scenario, using the "inferior" SPDIF inputs and RCA outputs, it still manages to sound pretty good. When paired with the right music and the right equipment though, it approaches reference quality for a fraction of what that normally would cost. I've got an Esoteric D-07x sitting here right next to the Tobby and at $5,000 I'm struggling to find it superior in any category. Obviously it looks quite nice, and has more brand name appeal, but that's about the extent of it. I'd say this reflects somewhat poorly on Esoteric, but  also rather favorably on Firestone Audio. If this type of signature gets you going, the Tobby DAC is absolutely worth a listen. [/size]

[size=small]DSD is all the rage these days. Despite there not being a whole lot of music available in the format (SACDs aside), DAC makers are jumping on the feature as fast as they can. And I can't blame them - aside from our "regular" music, we all love a little ear candy to show off the capabilities of our system. [/size]
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[size=small] Another thing that's quite popular? The ESS Sabre DACs. These Sabre chips show up in more and more products, eclipsing the the competition from Wolfson, Cirrus, Analog Devices, and Texas Instruments in desirability and "buzz" if not sheer volume of sales. And the ES9018 is their top model. It appears in many excellent DACs including my own reference units. [/size]
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[size=small] What about USB? The big thing these days is asynchronous operation, which is basically standard fare for any DAC with higher-end aspirations and is even crowding into the more affordable gear. One of the most popular implementations is based on the XMOS chipset, which is seen in many highly regarded DAC and USB to SPDIF converters. It's certainly not the only game in town but is used in enough high-end products to be considered one of the more desirable solutions.[/size]
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[size=small] Matrix Audio, a company which basically got their start with the $300 M-Stage headphone amp, moves upscale with the release of their new flagship X-Sabre DAC ($1099). It ticks all the boxes - DSD compatibility. ES9018 Sabre DAC. XMOS USB. Of course, none of that matters by itself - the device needs more than just buzzwords to be worthy of our consideration. Luckily the X-Sabre has more going for it.[/size]
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[/size]
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[size=small] DESIGN[/size]
[size=small] The Matrix X-Sabre is what I'd call a "typically sized" DAC, at least in the HeadFi world. It's approximately 10" wide, 8" deep, and about 2" tall. The first thing you notice about it is the weight and construction - the unit weights 8 pounds and is CNC machined from a solid block of aluminum. You might be thinking to yourself that 8 pounds is not so much, but from a device of this size it might as well be a ton. Separate internal compartments are used for each section which supposedly helps isolate them from interference. It also isolates them from being examined in detail - the bottom panel comes off easily but the resulting view merely shows the bottom of the PCBs. I did end up removing the guts which I'll show later.[/size]
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[/size]
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[size=small] Everything on the front panel and rear panel is pretty self explanatory, so I'll just point out a few things I find noteworthy.[/size]
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[size=small] *There is no optical input. To be honest, I rarely use optical as a connection, and I suspect most people are with me on that. But of course there are exceptions and I imagine someone might find this to be an issue. In exchange we do get an AES/EBU input which is not always included with all DACs. [/size]
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[size=small] *The unit is supported by 3 "feet" in a sort of triangular configuration. I thought this might end up making it tipsy as compared to a foot on each corner, but that hasn't been a problem. [/size]
[size=small]  [/size]
[size=small] *The front panel LEDs are very well done - bright enough to be seen, even from a distance, but not overly bright like the majority of LEDs on audio gear. This may sound petty but for me it's kind of a big deal - so much gear has a blazing LED that lights up the room. I'd like to see all equipment handled like the X-Sabre. [/size]
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[/size]
[size=small]  [/size]
[size=small] *Balanced and single ended outputs are both active at all times. [/size]
[size=small]  [/size]
[size=small] *RCA outs are a relatively common 2.2Vrms. XLR, on the other hand, is rather high at 6.8Vrms. The norm is closer to 4Vrms - Anedio D2, Resonessence Invicta, and Schiit Gugnir are all 4V. Violectric V800 comes stock at 4.3Vrms, though it can be made to go higher via internal jumpers. This high output basically means some amps won't have as much volume adjustability when paired with the X-Sabre. I didn't have any major problems myself, but some amps already have dangerously high gain, and this combo may push them over the edge for some more sensitive headphones. [/size]
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[size=small] *Build quality. I just can't say enough about the fantastic look and feel of this thing. It's currently sitting in my rack next to the $4,000 Resonessence Labs Invicta, the $1,800 AURALiC Taurus, and the $4,800 Esoteric D-07. The little X-Sabre, priced considerably less than those, does not look at all like a cheaper class of equipment. In fact it's arguably among the best of the bunch. Aesthetics are subjective of course but I find its look (which I call "high-tech minimalist") to be well thought out as well as beautifully executed. [/size]
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[size=small] Once the guts are removed (which is more difficult than usual but not too terrible), we can see the main components. The design breaks down to three "sections", which are almost completely isolated from each other and are connected by ribbon cable similar to what you'd find in a computer. [/size]
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[size=small] The most simple is the front panel board which houses the power and source switches as well as the LED indicators. Interestingly, the LEDs themselves don't actually shine directly through the front panel. Rather, each LED shines upwards to illuminate a translucent tube (likely plastic), which then carries that light through to the front panel. This indirect lighting is why it looks so soft and non-invasive, which I love. [/size]
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[size=small] Next comes the power supply board. Main components here are an array of 4 Nichicon Muse FWM 2200uf capacitors along with 2 more of the same rated at 4400uf. There are 3 LM317 linear regulators and a total of 11 ultra-fast recovery rectifiers from On Semi. Set aside in an isolated section away from the power board is a custom toroid from Noratel, which rounds out the major components of the PSU.[/size]
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[size=small] Last but not least we find the actual DAC board itself. Obvious bits that we already knew about - ESS Sabre ES9018S DAC chip running in quad-mono mode (4 DACs per channel). XMOS chip for USB supported by separate discrete clocks for 44.1kHz and 48kHz (and their multiples). Other things which I had been curious to find out about - a high quality, low phase noise HLX system clock at 100 MHZ. Winbond 25x40 flash memory and a PIC microcontroller for system operations. I didn't see an FPGA chip, so there probably isn't much chance of system updates.... not that the unit really needs upgrading since it already handles DSD and DXD. [/size]
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[size=small] I spotted an SMSC USB3310 USB transceiver - not something I recall seeing in my other XMOS-based DACs. I was not sure why this would be used but a quick check shows a variant of that chip being present on the XMOS reference board. It seems Matrix is actually doing things "by the book" even if others have found alternatives. I don't see any dedicated DIR so I presume Matrix uses the digital receiver functionality built-in to the ES9018 itself. That's been known to be somewhat touchy in other DACs - see Yulong D18 and Eastern Electric MiniMax for examples. Perhaps this helps explain the otherwise curious omission of a Toslink input, which is known for its higher jitter. I've been using the X-Sabre with every source available and have yet to have dropouts, but I'm apparently lucky as my Yulong D18 never gives me trouble either.[/size]
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[size=small] The analog output stage is based around 6 of the National Semiconductor LME49710 opamps. I believe it is configured as 2 per channel for XLR, and 1 each for RCA, but I could be wrong. There's also an NE5532 floating about, though it doesn't appear to be in the main signal path. Perhaps it is used for something like impedance matching as in the Violectric gear. Takamisawa relays cover both outputs, helping avoid pops during power on or off. Overall the output stage is surprisingly simple considering the resulting sound quality. But hey, if it works, it works. [/size]
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[size=small] DSD and DXD[/size]
[size=small] I'm making a special section here because this is one of the big selling points of this device. The X-Sabre supports DSD64 and DSD128. You'll need playback software capable of handling DSD - JRiver and Foobar2000 are the options I tried (Windows), though others exist: Signalyst HQPlayer and JPlay for Windows, Pure Music and Audirvana Plus for Mac. Matrix provides Windows drivers for the X-Sabre as well as detailed setup instructions - JRiver is easy but Foobar is rather involved. I got it going in about 10 minutes though and if I can do it, anybody can. I confirmed that the X-Sabre uses the latest DoP v1.1 but can also fall back to v1.0 if the playback software doesn't yet handle the latest update. Also, when using the ASIO driver with Foobar, DoP is not being used. Not that it really matters as DoP is just the container and the resulting playback is still very much "true" DSD. [/size]
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[size=small] DSD is not widespread but there is some material available for purchase: scroll down for a list. Of note is2L Records which offers lots of free downloads including hi-res PCM, DSD, and DXD. Also check out DSDFile.com where Opus3 records has a few free downloads from their two DSD Showcase albums (highly recommended). [/size]
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[size=small] What about DXD? Never heard of it? It stands for digital extreme definition and is essentially a very high bitrate PCM signal at 24-bit/352.8kHz. DXD files are massive, even compared to DSD files. It's an uncompressed format (think WAV as opposed to FLAC) so that makes it even worse. For example - 2L Records has a Mozart Violin Concerto, 9 minutes and 24 seconds, available in various formats. 24/96 FLAC is 171MB. The same file in 24/192 is 338MB. The DXD version is 1GB, which is even larger than the DSD64 (274MB) and DSD128 (581MB). So DXD is nearly twice as large as the next biggest format. Yikes. An entire album (depending on the length) might not even fit on a single layer DVD. But it sounds mighty nice, and I'm always happy to take all the playback capabilities I can possibly get.[/size]
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[size=small] A quick word on the state of things - DSD is a major buzzword right now. DAC makers are scrambling to update firmware, or revise designs, as needed to enable DSD support. In a way, I feel it's kind of a gimmick considering how much music is actually available for these DACs in the format (the answer being not much at all). However, at the same time I also feel it's kind of an important feature to have. Remember that the SACD format used DSD so there are quite a few albums out there already in the format. As time goes by I think we'll be seeing more and more releases become available. [/size]
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[size=small] No matter what the audio mags and websites tell us, SACD was a failure in the grand scheme of things. There hasn't been a plant pressing SACDs in the USA for years, and there are hardly any dedicated SACD players being made these days. On the other hand, universal disc players are rather common, and there was something like 6,000 SACD releases in total. Even counting some of those as being mere PCM to DSD conversions, and some being multi-channel rather than stereo, that still leaves quite a few titles usable by the regular 2-channel music lover. As HDtracks and other sites look to increase sale, and notice all these new DACs with DSD playback capabilities.... it only makes sense that they will scramble to get more DSD downloads ready to go as fast as possible. People who already own the 16/44.1 version of a song might not feel the 24/96 version is worth the money to re-buy. But maybe they'll feel like DSD is a big enough improvement. I can guarantee that HDtracks is thinking that very thing. Perhaps DSD can have a second renaissance via downloads where it failed the first time around on physical media.[/size]
[size=small]  [/size]
[size=small] So where does this leave us? Simply put, DSD is not enough on its own to justify buying a DAC. It might be more and more relevant as time goes by, but redbook playback is still the defining characteristic of any DAC. Having said that, the situation reminds me of 192kHz USB support: I've had people specifically tell me how such-and-such DAC was perfect for them but they couldn't buy it because USB topped out at 24/96. I ask them if they have any 24/192 material in their library, and they reply "no, but someday I might". [/size]
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[size=small] SERVICE[/size]
[size=small]  [/size]
[size=small] A quick note about service: the X-Sabre is available worldwide from the global Matrix website. Customers in the USA (and probably Canada as well) should go through the North American distributor. US distribution is handled by a fellow named Arthur who I can vouch for - we've been chatting since long before he picked up the Matrix line, and he's always been very informative and helpful. Orders through his site are drop shipped directly from China, but all service would go through him. So if you had questions about anything at all - for example, needing a walk through due to driver issues, or DSD playback, or whatever - he'd be there to help. Or in the unfortunate event of a hardware issue, the unit would be mailed to him in New Jersey rather than back to China. I know RMAs are one of the sticking points for people who prefer not to order gear from China, so a helpful local distributor is great news in my opinion. Having him be a nice guy and a native English speaker is even better.[/size]
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[size=small] EQUIPMENT[/size]
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[size=small] I used the following gear during my evaluation of the Matrix X-Sabre, down to the last excruciating detail because some people have asked for that:[/size]
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[size=small] Source: Auraliti PK90 USB server powered by NuForce LPS-1 power supply, connected direct over USB or else routed through an Audiophilleo AP1 with PurePower, Acer laptop running Foobar2000 or JRiver Media Center, Cambridge Audio 740C[/size]
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[size=small] AMP: AURALiC Taurus, Violectric V200, Icon Audio HP8 MkII, Firestone Audio Bobby, Analog Design Labs Svetlana II, Stax SRA-12S[/size]
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[size=small] Headphones: Sennheiser HD800, Stax SR-007 MKII, Audeze LCD-2.2, Beyerdynamic T1, Thunderpants, Frogbeats C4, Cosmic Ears BA4, Heir Audio 8.A, Sensaphonics 3MAX, JH Audio JH13pro FreqPhase, 1964 Ears V3[/size]
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[size=small] Power conditioning: CablePro Revelation, Yulong Sabre P18[/size]
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[size=small] AC cables: CablePro Reverie, Charleston Cable Company Auric Ohno[/size]
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[size=small] Interconnects: Charleston Auric Ohno, NuForce Focused Field, Signal Cable Analog Two, Pailiccs Silver Net[/size]
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[size=small] Digital: NuForce Precision coax, Charleston Auric USB[/size]
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[size=small] Headphone Cables: several models from Toxic Cables, Beat Audio, Charleston Cable Company, and 93 East[/size]
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[size=small] LISTENING[/size]
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[size=small] I knew people were curious about my impressions, and I had been held back from doing serious listening of the X-Sabre while I finished up my review of the NuForce DAC-100. So once I was ready to focus on the Matrix unit, I didn't mess around. I launched straight into some serious listening on the best gear I have in the hope that I would quickly lock on to the character of this device. As usual, life got in the way, and it's taken longer than I had hoped.[/size]
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[size=small] My first serious notes from listening to the X-Sabre can be summarized like so - clean, resolving yet slightly relaxed presentation with smooth but extended highs, great timbre, and a nice sense of coherence from top to bottom. That pretty much sums it up and you can stop reading right now if you want. Or not.[/size]
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[size=small] In the school of DACs, there are a few archetypes that most people are familiar with: There's the overly slow, warm, syrupy type. There's the hyper detailed, analytical thin type. Everything else falls somewhere in between those two, with most leaning more towards one side or the other. Very few are absolutely in the middle, and those tend to be on the expensive side anyway. Not to mention most people have a hard time agreeing where exactly that middle ground lies. [/size]
[size=small]  [/size]
[size=small] The Matrix X-Sabre is not quite in the middle. To my ears it leans a bit towards the so-called "musical" side rather than the more dry, analytical side. Thankfully it avoids many of the downsides of its musical brethren - it's not slow, not rolled off in the least, doesn't have mushy bass, and doesn't impart too much coloration onto the sound. It also avoids many of the downsides of the analytical type - it's not etched and harsh on the top end, and it's certainly no lightweight on the bottom. Best of both worlds? Not completely. Some DACs have better detail retrieval, some have more textured bass, some have a more clear, transparent presentation. But overall I'm very pleased with the X-Sabre. $1100 is not cheap but in the grand scheme of things it's not a vastly high price for a DAC. Some compromise was necessarily involved, and Matrix seems to have done a good job prioritizing. [/size]
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[size=small] Those last few lines might just hold the key to explaining why I like the X-Sabre so much. As I survey the competing DACs in the $800-1500 range, I can generally find one that outperforms the X-Sabre in any single aspect. Yet very few of them can perform so collectively well in all areas. There are many analogies that might apply here - the well balanced athlete who might not headline a Nike commercial but nevertheless has a long and fruitful career, earning many millions of dollars in the process and being well respected by peers and fans alike. Or how about the neighborhood restaurant that you love, with a widely varied menu - they don't specialize in any one area so it is possible to find a better steak, better pasta, better fried chicken... but those come from specialty places which don't have near the selection of your favorite spot. I could go on and on but hopefully you get the point - the X-Sabre is really good across the board, if not quite the best at any particular aspect. [/size]
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[size=small] A few more noteworthy things to mention:[/size]
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[size=small] *Soundstage is very impressive. It's got that nice open feeling that proves elusive even for many expensive DACs. If the X-Sabre was going to stand above the pack in any one specific area, this would be the one. [/size]
[size=small]  [/size]
[size=small] *Warmth. As I'll continue to explain, the X-Sabre is slightly on the warm and smooth side. It's not a rolled-off tubey NOS sound or anything of the sort but it does help take some of the "bite" way from certain recordings - in a good way. I don't feel like I'm missing much in terms of attack on well recorded tracks, but harsh sounding mediocre recordings do get a gentle helping hand. I did notice some treble glare in the early hours of listening but this seemed to fade as I clocked more time on the unit. Perhaps it never completely went away in the grand scheme of things (as compared to my Resonessence Labs Invicta for example) but it's not something that bothers me now, after several hundred hours.[/size]
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[size=small] *Input differences. I mainly used USB connected to my laptop. It sounded really good that way. It took a lot of effort to improve on it with a USB to SPDIF converter - the Stello U3 sounded worse, with a slightly more edgy feeling that threw me off a little. It wasn't terrible but it did lose some of the charm as opposed to the USB input. The Resonessence Concero used as DDC is very difficult to discern from the native USB input, at least when used in the standard mode. When applying the proprietary Resonessence upsampling filters (IIR or apodizing), small changes in character are present. I particularly like the minimum phase IIR filter in this case but it's nothing so large as to justify the $599 Concero being a mandatory add-on. Finally, I went all out with the Audiophilleo AP1 with PurePower battery option. That combo did raise the bar in terms of transparency, imaging, and fluidity of the midrange and upper mids. I enjoyed it but when it came time to return to the native USB, I didn't find myself going through withdrawals or anything. Lastly, I tried my Cambridge Audio 740C as transport over coax and optical cables. X-Sabre again sounded more edgy, much like when I used the Stello U3. It wasn't bad sounding in absolute terms and if that's all I had available I'd definitely still enjoy the device... but I just enjoy it more through USB. I didn't have a chance to use my JF Digital music server which has less jitter on the SPDIF output. It might have sounded closer to the USB, but I was too lazy to move it out of my living room system. [/size]
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[size=small] *I don't notice any difference between the RCA and XLR outputs, aside from the higher XLR output voltage which I mentioned earlier. It's possible that some minor difference exists, but if so it's small enough to be inconsequential in my opinion.[/size]
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[size=small] I spent a lot of time listening to some exceptional DSD tracks. The Opus3 Records DSD Showcase albums are definitely worth buying if you want some demo material. At $12.99 for DSD128 and a mere $9.99 for DSD64, they are a definite value compared to some of the overpriced hi-res albums out there. I'd still enjoy "Where the Green Grass Grows" by Eric Bibb even if it was a low bitrate mp3 file.... but this DSD version is perhaps one of the most lifelike recordings I've heard, anywhere, ever. I spent most of my time with the DSD128 version because hey, why not? To be honest, the DSD64 version sounded similarly excellent, to the point where I'm not sure I can reliably tell them apart. But I didn't specifically try so that's a story for another day. Both of them have rich tones, lifelike airiness, pinpoint imaging - your name an audiophile cliche, and it's in this track to a very high degree. I was also exceedingly impressed by The Erik Westberg vocal ensemble & Mattias Wager – Nun kommt der Heiden Heiland, which has some killer organ that really plumbs the depths. The lows on this track will lay bare the differences between a reference caliber headphone - LCD-2, 8.A, SR-007, JH13, etc, and one that is merely "pretty good" - W1000X, HD650, DT880, etc.[/size]
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[size=small] Not to be outdone, DXD tracks sound very nice too. I have Quiet Winter Night by the Hoff Ensemble, which like many recent hi-res releases was originally recorded in the 24-bit/352.8kHz DXD format and later converted to DSD or various PCM options. I have a hard time believing DSD can be any better because the DXD release is already spectacular. I got this album as a promo - one of the best parts of becoming a "real" audio journalist - but I only have this one version. If I was buying, I'm not sure I'd want to pay almost double for the DXD as compared to the plain ole' 24/96 FLAC version. Then again maybe I would if the difference was noticeable. This sets off an interesting discussion about why this price discrepancy exists for download versions - but I won't get into that here.[/size]
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[size=small] What about hi-res PCM, which is practically becoming yesterday's news in light of these new DSD/DXD options? It still sounds great on the X-Sabre. All of my usual reference material was highly enjoyable - Conga Kings, Traffic by CBW, Wilson Pickett, Norah Jones... if one never listened to any DSD, this DAC is still very impressive.[/size]
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[size=small] Then we come to "boring" Redbook quality material, which still happens to make up a huge majority of the music in our libraries. Isn't it of limited quality and difficult to listen to after all that amazing hi-res stuff? Yes and no. By its very nature, hi-res releases in all formats tend to be some of the best recordings out there. Yes, there's the occasional sneaky upsample, and some modern popular releases that make no sense to buy in hi-res due to their inherently poor dynamic range. But those are the exceptions - most hi-resolution material also sounds very good in the standard CD release. In contrast, stuff that only ever came out on CD can be rather mediocre or sometimes downright terrible. Stuff like Rush or Red Hot Chili Peppers is especially annoying when the music is enjoyable but the recording is not. Yet many counterexamples exist - try the Steve Hoffman Metallica DCC remasters, any Hiromi album, any Yo-Yo Ma album, anything from Reference Recordings, most albums by Peter Grabriel or Genesis, almost any Miles Davis or Otis Redding or Alison Krauss & Union Station or Bill Evans or.... you get the idea. Redbook material can sound downright bad but it can also be very, very good, and we should be careful not to place all the blame on the format. The X-Sabre handles the good stuff really well, and due to its slightly smooth character, is better than many when it comes to the bad stuff. I guess what I'm trying to say here is that great recordings exist in many formats and the X-Sabre can pretty much play them all. [/size]
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[size=small] COMPARISONS[/size]
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[size=small] Rather than going any further down this road, I want to switch gears and talk about some specific comparisons with the various DACs I have at hand. This will hopefully prove illuminating for someone trying to decide between two contenders, as well as helping flesh out the performance characteristics of the X-Sabre. I used a lot of gear for my general listening, but for these specific comparisons I used my electrostatic setup consisting of a Stax SRA-12S with the Stax SR-007mkII. The SRA-12S (recently worked over by Spritzer and given a Pro output) is an old-but-still-very-nice Class-A solid state unit which to my humble ears is superior to many of the current production models including the SRM-727II. Stax intended it to be a preamp as well which means it has plenty of inputs - perfect for comparing several DACs in the same system. Care was taken in terms of level matching (which is no fun but very necessary for proper comparison).[/size]
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[size=small] NuForce DAC-100: I just finished reviewing this DAC and it's very enjoyable overall. At $1100 it is a direct competitor for the Matrix.There are some obvious differences in terms of features - Matrix gives you DSD capability and balanced outputs while NuForce has a headphone amp and preamp capabilities. Obviously these different feature sets will each appeal to a different user.[/size]
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[size=small] Strictly focusing on sound quality from the DAC section - these are totally different sounding devices. The NuForce can be summarized by the words "lively", "exciting", and "dynamic", but it isn't the last word in micro-detail or gracefulness. The X-Sabre has better detail retrieval and a smoother, more relaxed presentation that flows more easily. They both have their unique moments to shine - the DAC-100 better captures the scale of The Planets by Gustav Holst, or the intensity of heavier acts such as Shai Hulud or Stretch Arm Strong. In contrast, the X-Sabre is better at revealing the quirky/brilliant nuances of music from composer Harry Partch, allowing me to better notice the interesting rhythm and (micro)tonality of his complex works like Delusion of the Fury. It also excels with technical metal - Meshuggah, In Battle, Becoming the Archetype, Opeth, Theory in Practice - while these bands are all undeniably heavy, their music is also very complex, and the X-Sabre resolves their detail better than the NuForce while at the same time maintaining a non-harsh sound (which is welcome since these bands don't always make the best recordings). It's not that the DAC-100 sounds bad with these, but the X-Sabre just does it better. Your system, music, and preferences will determine which might work best. Well recorded stuff from Norah Jones or Patricia Barber or Frank Sinatra will sound really nice on either DAC, but vocals are more penetrating and real with the X-Sabre. Both are still very enjoyable. [/size]
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[size=small] Which one do I like more? That's tough. The value proposition of the NuForce is hard to deny - DAC-100 plus HD800 and you've got a simple but great sounding setup. Then again, people shopping for a DAC in the $1000+ price range might already have eyes on a nice stand-alone amp, negating the benefit of that integrated amp. If we leave out build quality, looks, functionality, etc and focus purely on sound quality as a DAC, I'd say the X-Sabre takes the lead, at least in my system and with the music I prefer to listen to. If I primarily used coaxial SPDIF rather than USB, my choice would not be as clear, as the NuForce sounds the same on those while the Matrix goes down a notch compared to USB. [/size]
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[size=small] Resonessence Labs Concero: This little unit is probably not on the radar of most people looking for a $1K DAC. Maybe it should be. Obvious feature differences aside, the Concero comes surprisingly close to the X-Sabre. The Matrix comes out ahead in areas like treble realism, midrange openness, and soundstage depth. X-Sabre seems to be a little smoother too. Surprisingly, the Concero keeps up in the lower regions with excellent bass texture and realism - so much for the idea that beefy power supplies always equate to superior bass. But overall when using a really nice headphone like HD800, Stax, JH13, etc, the X-Sabre pays dividends in overall realism. It's just more convincing in that "last bit", audiophile sort of way. That said, if you want to spend less money and don't have a need for balanced outs or DSD playback, Concero is an excellent choice. [/size]
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[size=small] Musical Fidelity M1A: I don't care that this DAC won various awards in magazines - I dislike it immensely. To my ears it sounds blurry and indistinct while at the same time being harsh and splashy on the top end. I guess that's an impressive accomplishment in a way... X-Sabre is far superior to the M1A in every category. OK, the Musical Fidelity unit is $350 cheaper, but if money is an issue I recommend the Concero without hesitation. It's even cheaper and still sounds better too. [/size]
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[size=small] PS Audio NuWave: I didn't really care for this one either. It certainly looks great and has a nice balance of features for the money.  I really wanted to like it. But the sound.... it just seemed a bit too bright, too plastic, too thin. I imagine some people like this sort of thing and hear it as extra detail but for my taste it was just too much. X-Sabre has a far more natural tone and still has plenty of detail - in fact it does cymbals in a significantly more realistic way. Just because they are boosted, doesn't mean they sound real, and that's where the NuWave gets it wrong. At $999 or even at the discounted $799 price I already see in certain places, there's no way I could recommend the NuWave over the X-Sabre. PS Audio might sell a ton more than Matrix due to their name brand, but my recommendation lies strictly with the X-Sabre.[/size]
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[size=small] Violectric V800: I love the V800 - it's got a neutral, clear sound without being sterile or harsh, and it still has enough soul to move me. It's one of my favorite DACs at any price, period, and proves to be tough competition whenever I review a new DAC. In comparison, the X-Sabre is very close in quality but with a different flavor. It's a little smoother but also bit less resolving of tiny details. That's the main difference - X-Sabre has more perceived warmth, which can make it easier on the ears with mediocre recordings, while V800 goes a little farther with reference quality material. At times I felt like the V800 made the X-Sabre seem a little "glassy" in the highs, but I could never get this to be a consistent thing. Soundstage on X-Sabre is about the same in width but has the slight advantage in perceived depth. The trade off - V800 has more accurate imaging. This soundstage/imaging difference is only really noticed when using an excellent chain of equipment though. Once again the feature differences are split down the middle, so either of these units comes highly recommended by me. [/size]
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[size=small] Yulong D18: The D18 has been my favorite "budget" ES9018 based DAC for a while now. From the balanced output, it's more exaggerated than the X-Sabre - smoother and warmer. From its RCA outs, it is more neutral. It's great to have both options, but the X-Sabre offers a nice middle ground presentation between the two, while being a bit more resolving than either. Bass is very slightly more extended if not quite as prominent as D18 via XLR, and top end detail is more believable, though at times the D18 would be a better match for some systems, especially for people who are extremely sensitive to any kind of treble glare. The differences are not huge though - D18 is still a very good DAC and at $699 it remains a great value. It has no USB input but a good DDC can be had for a reasonable price, allowing the combo to still be as cheap or cheaper than the X-Sabre. But overall the Matrix unit is slightly better as a whole. Should D18 owners bother to "upgrade"? If they are pleased with their unit then I'd say probably not. The X-Sabre is not really different enough to warrant a switch. The exception would be if someone had a D18 and was mostly pleased with it, but found it a little too smooth on the top end in balanced mode. I've talked to several people who felt that way but at the time had nothing else to recommend to them. Now I do. [/size]
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[size=small] Anedio D2: This is where the X-Sabre is finally outclassed. It's not by a massive amount, but I do feel the D2 is in another league in several areas. It's got better leading edge definition, superior low frequency texture, and more transparent midrange too. But it also costs $400 more which is around a 36% increase in price - that's substantial. And some people may actually prefer the slightly warmer X-Sabre sound depending on their system. In order to upgrade from the D1 without a major price increase, Anedio used a less costly enclosure for the D2, and it shows. It's still attractive and all, but the X-Sabre looks and definitely feels like it should be the more expensive product. And the Matrix unit is available right now for order while Anedio is constantly sold out with a potentially long wait. I'd never talk anyone out of buying one of my favorite DACs and if you can afford it (and can wait for it) by all means put the D2 on top of your list. That still doesn't minimize the quality of the X-Sabre.[/size]
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[size=small] Others: Without specific comparisons, I'll just say that I prefer the X-Sabre over some well known and well regarded units like Benchmark DAC-1, Bryston BDA-1, Rega DAC, Wyred 4 Sound DAC1, North Star Essensio, Grace Design M902, and Lavry DA-10. To my ears the X-Sabre sounds better than most of those, or in a few cases sounds similar but costs way less. I know this is vague but I don't have any of these on hand right this moment so I can't get down to the nitty-gritty of each one.[/size]
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Conclusion
Ever browse for an Android tablet and notice some of the "off" brands out there? There are plenty of them which seem to have unbelievably good specs - quad core CPU, lots of memory for both RAM and storage, SD card slot, HDMI out, large screen with great resolution, the latest Android build, replaceable high capacity battery.... essentially everything you could possibly want. And the price will tend to be significantly less than models established brands like Asus, Samsung, or Acer. Despite all the specs and features, my experience with these types has yet to pan out. There's always a catch somewhere. Maybe that screen with the great specs actually has a poor viewing angle or dull colors. And maybe their Android install is packed full of non-removable bloatware. And maybe that so-called "high capacity" battery only nets a few hours of real-world use. And maybe that 1.5 GHz quad core CPU can only comfortably manage 1.0 GHz before having heat issues. My point here? Shopping with an eye towards features per dollar is not always advantageous. 
 
Fortunately, the Matrix X-Sabre avoids that sort of thing. Yes, it does have a lot of things going for it - top level ES9018 Sabre DAC, balanced outs, impeccably built enclosure, XMOS asynchronous USB, and DSD capabilities. But at the core of the device is really good sound. Without that, features become little more than gimmicks, and the perceived value rapidly diminishes. With it, features actually become relevant, and value is added.
 
I recommend the Matrix X-Sabre for anyone who wants a well rounded DAC in the $1K price range. Is it the best DAC out there? Of course not. I can point to other DACs with better performance in various areas and by all means - if you're a detail freak or want an ultra-smooth NOS sound or have any other specific attribute that you value above all others - the X-Sabre, as a jack of all trades (but master of none as the expression goes) might not be your ideal match. Yet for overall competence I can't think of another unit to recommend more highly for the price. Add in local service and support from the new US distributor, and you've got yourself a winning package. Highly recommended. 
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