Confession time: I don't really like reviewing cables. It's a controversial topic that can often be more trouble than it's worth. And even when dealing with a crowd of cable enthusiasts, most would generally agree that cable upgrades represent a much smaller change in sound compared to swapping headphones, DACs, or amplifiers. I tend to think of cable upgrades as a "last few percent" type thing - squeezing the absolute best performance out of the system I already love. With this in mind, I actually have done the occasional cable review, such as when I first discovered Effect Audio cables way back in 2013. This is opposed to something like Moon Audio, whose cables I use and enjoy but have never reviewed - they are already well-known enough to where I don't feel I have much to add.

Today's topic is Audio Art, a brand which has been around since 2005 but wasn't very familiar to me until recently. Owner Rob Fritz is extremely responsive and easy to work with - one of a small number of folks in the industry with whom I find myself veering off topic to discuss music and other gear aside from cables, because he's just so approachable. I've become so taken with his products over the past year that my reference system is now wired with the power1 ePlus AC cables... keep in mind that I've got many, many AC cables to choose from, including some very expensive/high profile names. But I just enjoy the Audio Art power1 ePlus more, regardless of price or brand recognition. I'm also using the superb Audio Art D-1SE digital cable whenever a DAC features BNC inputs (unfortunately not all of them do). At some point I'm likely to pick up a few interconnects as well, just based on my satisfaction with the rest of their offerings.

Thankfully Audio Art now has a couple headphone cables in their lineup, which I'm told is a fairly new development. The HPX-1 Classic (starting at $300) is the "base" model, and the HPX-1SE (from $380) offers step-up performance for what I consider a reasonable upcharge. These are available in various lengths from 5 feet to 15 feet, and with a variety of termination options on either end. If you end up with some obscure application which isn't covered by the standard ordering menu, I'm fairly sure the company can handle your request via email. So don't be afraid to ask.



Under review is an HPX-1SE terminated with a rhodium Eidolic 4-pin XLR. On the headphone end, I chose the Eidolic mini-XLR plugs because they work with various headphones from Audeze, Meze, ZMF, and Kennerton, as opposed to most other types which only accommodate one specific model. I also like how robust the connection method feels - much more confidence inspiring than either style used by HiFiMAN over the years, and easier to deal with than the MrSpeakers connectors. This means I can use the HPX-1SE with my Audeze LCD-3, LCD-2, and Meze Empyrean, and not be concerned about wear and tear with frequent switching (unlike my HE1000 and Susvara, where I do in fact worry).



In describing the cable, Audio Art tells us the following:

"Our HXP-1SE features 2 paralleled cables with twin 28 awg single crystal OCC Copper conductors in each PVC jacket, insulated with PE dielectric. Left and Right channels are independently shielded with a braided silver-plated OFHC copper shield . The intention of this design is for high resolution audio performance, multiple application compatibilities, and rugged durability. Hand built in San Diego, California."

On looks, the HPX-1SE is what I'd call understated and classy. It's not the thickest cable, nor does it feature any flashy accents. But it's nonetheless attractive in its own way, and feels robustly made, with enough flexibility to be comfortable in use (unlike the stock Meze Empyrean cable which is rather unwieldy).




Although my system fluctuates regularly for review purposes, the bulk of my listening was done using the following gear.

*Core Power Technology Equi=Core 1800 balanced power conditioner
*Nativ Vita streaming Roon, where Roon Server is run on an Asustor AS6404T NAS in another room
*Titans Audio Labs Helen reclocker
*Resonessence Labs Mirus Pro Signature DAC
*Niimbus Audio US4+ headphone amplifier
*Audio Art power1 ePlus AC cables with Furutech FI-28(R) Rhodium connectors for all components
*Cabledyne Silver Reference AES/EBU cable from transport to reclocker (only certain low profile cables fit with the Vita)
*Audio Art D-1SE BNC cable from reclocker to DAC
*BetterCables Blue Truth II XLR cables from DAC to amp
*Audeze LCD-2, LCD-3, and Meze Empyrean headphones


First up was the LCD-2, which is actually my most-used Audeze headphone. This particular set is what we used to call the LCD-2.2, meaning it the last iteration before Audeze rolled out their "Fazor" technology which fundamentally changed the sound, not necessarily for the better in my opinion. I've gone through numerous sets until I arrived at this "unicorn" example, which to my ears has visceral low end impact, creamy mids, and a tastefully smooth top end which is forgiving yet detailed enough for versatile listening enjoyment.



Switching back and forth between the stock Audeze "ribbon" style cable and the HPX-1SE, I notice a subtle but worthwhile improvement in treble clarity. Not necessarily more extension, as the tonal balance is unchanged. Yet I hear cymbals, triangles, and particularly trumpets come through with more realistic attack as well as more believable note decay. For example, on the excellent XRCD release of Tiger Okoshi's Color of Soil, I feel the "bite" of the trumpet more distinctly than with the stock cable, while at the same time finding it less fatiguing at higher volumes. When the sound comes through more clearly, it can be more dynamic and alive while simultaneously feeling less artificial, and thus not triggering the part of the brain that says "turn that down".

Midrange remains untouched by the HPX-1SE - in this case an absolutely perfect outcome. This particular LCD-2 is rich, creamy, almost saturated through the mids, and I would not want to change a single aspect of it.

Low-end extension and body seem very slightly improved. I notice a touch more tonal richness from the double bass on an SACD rip of Gary Karr Plays Bach, along with a similar feeling of increased authority on Yo-Yo Ma Plays Ennio Morricone. Again, these improvements are subtle, and by no means does the Audio Art cable change the fundamental character of the headphone. Yet between this low-end improvement and the superior treble clarity mentioned above, the result is a welcome fine tuning to an already exceptional headphone.



A reasonable argument might be to suggest the money would be better allocated to a higher-end Audeze, rather than using the LCD-2 with the added cost of a cable upgrade. Makes sense on paper, but I have already been through at least one example of every model in the LCD series. In fact I still own a very nice sounding LCD-3 (pre Fazor) that I settled on after going through about 4 different pairs. I quite enjoy it, and admit it is clearly the more neutral, resolving headphone compared to my LCD-2. It would be far more useful in evaluating gear, but I already have other headphones that perform that function even better. In terms of listening pleasure though, my LCD-2 is king.

Still, swapping in the HPX-1SE brings a more substantial improvement to my LCD-3. It sounds more liquid, more flowing than with the stock ribbon cable, while again bringing more clarity to the treble... which in this case feels more significant as the treble is more prominent with this headphone. While my preference remains for the LCD-2/HPX-1SE combo, I can't deny that the recabled LCD-3 sounds pretty amazing. The delta between them becomes smaller, and it really comes down to signature preference... I prefer the smooth, rich LCD-2 but could really make a case for the 3 as well.



Lastly, the Meze Empyrean, which has become my most used full-size headphone lately. I already dislike the stock cable for its stiffness so the Audio Art gets points on feel alone. As for sound, I didn't initially notice a huge difference... sure, treble was more clear, but it wasn't as significant as the Audeze models. After using the HPX-1SE for a week, I switched back to the stock cable (don't ask me why)... and immediately noticed a muffled, compressed sound signature. The difference was striking in this case - definitely on par with the change I heard with the LCD-3, or perhaps even greater. This change was nearly on par with switching between the two sets of bundled earpads that Meze includes with this headphone - a definite, clear change in signature.

The Audio Art cable opens up the top-end of the Empyrean in a very welcome way. It's not brighter per se, but more clear, open, and resolving. I'd call it treble "rightness" though I'm not sure that will make sense to all readers. The ample bass response of the Empyrean needs no further boosting and while the HPX-1SE does increase the sense of slam by a small amount, it seems to bring focus to the sub-bass region. So it's not initially obvious, nor does it significantly change the tonal balance of the headphone. The end result is a more open, clean sounding presentation with improved resolution, along with slightly more sub-bass impact if you really listen hard for it. Which for my taste ends up being pretty much ideal.



In the end, all three headphones benefit by a noticeable margin from adding the Audio Art HPX-1SE. Which makes it a worthy upgrade as-is. But I'd like to discuss one more thing - Audio Art makes an adapter cable system which allows the HPX-1 or HPX-1SE to be used with different headphones. I was able to use the adapters to make my cable compatible with both the Sony Z1R and the Focal Elex, while still being very low profile and comfortable.



Sony's Z1R is a weird headphone. It's certainly not neutral, and the experience brings to mind the boring-looking-yet-expensive Audio Note speakers - tactile, musical, but far from even-handed. Still, with the right supporting gear and the proper expectations they can be wonderfully engaging and fun to listen to. The Audio Art cable seems to make the Z1R a bit more linear and "correct" sounding, which to my ears takes away from the experience. I end up preferring my Moon Audio Silver Dragon which maintains the core signature while tightening everything up a bit.

Having said that, I can see how the HPX-1SE might be preferred by folks who don't necessarily love Sony's tuning on this headphone. It does end up sounding more neutral and controlled, which is something I've heard people wish for on more than one occasion. For my uses though, it's not an ideal match.



Focal's Elex, on the other hand, is a brilliant partner for the HPX-1SE. Again I hear improved low-end authority along with superior treble clarity, but this time midrange is a bit more fleshed out as well. Not enough to change the fundamental character of the Elex but it does make them feel slightly more tonally rich. I also notice improved staging and imaging accuracy. Elex is probably my favorite headphone in the sub-$1K space, and while the HPX-1SE brings it slightly above that number ($~1100 for the combo) I feel the result is definitely competitive with other headphones costing more (including Focal's own $1500 Clear).


Are cable upgrades worth it in all cases? Of course not. Your system has to be resolving enough to pick up on minor changes, and if it isn't then I'd recommend other upgrades first. Once you have everything else dialed in, quality cables can bring that exceptional system to an even higher level of performance.



Audio Art's HPX-1SE headphone cable is a very worthy entry into a crowded field of competitors. It did a superb job with 4 our of the 5 headphones I paired it with, and the 5th headphone was debatable based on listening preferences.

I also love the fact that Audio Art offers the adapter system, allowing users to get more bang for their cable buck. I've seen a few other brands offer conceptually similar adapters but the Audio Art system strikes a perfect balance between low profile and price - others I've seen are either too bulky or cost nearly as much as the entire cable.

Overall I can very easily recommend the Audio Art HPX-1SE. It's not as well-known as some of the big brands, but in my experience it offers better value and performance than many others in this price range. Definitely check it out if you are in the market for an upgrade.

Quick note - this is part two of a series covering various tweaks from iFi Audio. Part one focused on the Gemini3.0 dual head USB cable while the next post will cover the DC iPurifier2.

The focus of this installment is the iSilencer3.0, which is a $49 "USB Noise Eliminator". iFi promises the device will cancel noise via their "Active Noise Cancellation+" technology, as well as reduce jitter and "re align" the USB signal via their "RE Balance" feature. As with all iFi gear, I've learned to not get overwhelmed by the marketing terms and just listen for myself before passing judgement.



Conceptually, the device couldn't be simpler: a small dongle which plugs into any standard USB port on your computer/music server/etc and removes noise from the signal as it passes through to the DAC. It can also act as a filter between a playback machine and external hard drive where a music library is stored. Lastly, it can be plugged into any empty USB port and supposedly still bring a minor benefit, though I'm not quite clear on how that might work.

Cutting to the chase on this review - I found the iSilencer3.0 to be beneficial in some circumstances, while in other cases it didn't do much of anything. Which is pretty much par for the course for a device of this nature. Different situations yield dramatically different results, and it's fairly unpredictable - the places I thought it would make a noticeable impact, I was let down, while other applications yielded surprisingly impressive results. Thankfully the device is only $49 so it's not a huge investment to run your own experiments.



After trying the iSilencer3.0 with many different combinations of source and DAC, I heard the most significant impact with my Asustor NAS which doubles as a surprisingly high quality playback device. Even without the iSilencer3.0, I'm very pleased with the sound it produces when paired with DACs ranging from $80 to $8000. The iFi adds a bit of extra focus to the image, seems to somehow improve dynamics, and contributes to the sense of blacker background - which was unexpected as the NAS already does very well in that area. Certain DACs showed the improvement more noticeably than others, as I'll discuss in a moment.

The other area where I heard a very specific improvement was when paired with an old HP workstation. This water-cooled, Xeon-based, 6 core/12 thread monster just refuses to die, and has cycled through from being my main PC to a media server to a photo editing station (and probably some other uses I'm forgetting) over the past ~7 years without a single complaint. At the moment I have it paired with the excellent Keces Audio S3 which feeds a pair of Adam Audio F5 active monitors, and the result is very enjoyable.... with one small issue.

The problem: I get an intermittent static/buzzing noise that seems to come and go at random. The noise is not audible when using the integrated headphone output of the Keces. I've tried different DACs as well as adding a separate preamp for volume control, and the issue never went away. Which of course points to the speakers as being the culprit - except I only experience it when using them with this particular computer. The DAC itself doesn't seem to matter - it's one of those USB related gremlins that just doesn't make sense, and that fact probably bothers me more than the actual noise itself (which realistically isn't all that loud anyway).



The iSilencer3.0 is the only solution that I've found which eliminates this unwanted noise. I discovered this practically by accident, but I'm thrilled to find some way of ridding my system of the buzz. Again, while my particular issue isn't all that bad in the grand scheme of things, it gives me a taste of the varied and maddeningly "unsolvable" USB audio issues I've read about on the forums for years. If it had been a louder buzz, it would basically render this workhorse PC unusable for listening purposes. By solving this problem, the iSilencer3.0 more than justified its price, even without any other significant contribution to audio quality.

My other sources include music servers from Aurender, Euphony, and Nativ, laptops from Dell and Asus, and lastly a Surface Pro 6. None of them seemed to respond well to the iSilencer3.0. There were a few moments where I thought I heard a tiny improvement, but it was small enough as to not really be worth mentioning. To put it another way... if I hadn't experienced the SQ boost on my Asustor NAS, or eliminated the buzz from my HP, this write-up would probably only be a single paragraph.


Let's talk DACs, since my results varied from one to the next. Using the Asustor NAS, I heard benefits with the Massdrop Airist R 2R DAC, the RME ADI-2 DAC, and the Exogal Comet Plus, in roughly equal measure. The Airist is very sensitive to power and USB tweaks, so I wasn't surprised there. But the Exogal and RME units both claim advanced jitter reduction and I really didn't expect them to care about the little iFi widget. I was wrong - the resulting sound was clearly improved with the iSilencer3.0 in the chain. For perspective, Exogal's upgraded $500 PSU (which turns the Comet into a Comet "Plus" version) makes a larger difference, whilst the iSilencer3.0 is more worthwhile than the $199 WyWyres umbilical cable upgrade connecting that external PSU to the DAC itself. The WyWyres umbilical makes a very, very small improvement, but it carries over regardless of transport.... the iFi upgrade is more substantial with my NAS as transport, but not very noticeable with other devices. So which is the better value? There's no easy answer.

Other DACs, like the iFi iDSD Pro and the ModWright Oppo 205, did not care one bit about the iSilencer3.0 being in the chain. Neither did my reference DACs from Resonessence Labs and Wyred4Sound. For the latter, I even cranked the built-in jitter reduction all the way to its lowest setting, and still couldn't hear any impact whatsoever. This applied whether using an expensive music server or pedestrian laptop.


Bottom line - does the iSilencer3.0 really work? The best answer I can give is "sometimes". Based on my results, using certain sources with certain DACs, it has the potential to make what I'd call a significant and worthwhile impact. On the flip side, that result is by no means guaranteed, again based on my observations with various source/DAC combinations. Other iFi gadgets such as the DC iPurifier2 or the iPurifier3 USB seem to offer more consistent results, though it comes at double the price (or more) of the iSilencer3.0.... and of course all of these can be mixed and matched to potentially compound the improvement. In the end it really comes down to trial and error, and unfortunately that's something each person needs to to try for themselves.

iFi Gemini3.0 Dual Head USB Cable




Dual head USB cables have always struck me as interesting and fairly clever. Rather than a standard single-cable, source-to-DAC link, they split the power and signal connections into completely separate portions - which then combine at the DAC input. The result is a "Y" shaped cable offering a total decoupling of potentially dirty USB power from the source device. Users are free to instead use a high-quality supply on the power leg for the cleanest possible power.

If the USB stage of your DAC draws power over USB, as many of them do, one can imagine the benefits obtained - cleaner power is always a good thing. I recall being surprised when I first discovered that numerous DACs work this way, even when they have integrated or separate outboard supplies powering the rest of the system. But even in cases where USB doesn't draw any power, there's still potential for that dirty USB power to "contaminate" the incoming audio signal, which again impacts sound quality. You can read more on the topic here.

Does any of this really matter? I figured it was time to find out for myself. While various small boutique brands have offered dual head solutions over the years (Audiocadabra, YFS, and KingRex among others), I chose a more well-known firm for my little experiment: iFi Audio. Their first Gemini dual USB cable launched way back in 2013, so they've been at this for a while now. That model was what I'd call "midpriced" in the grand scheme of USB cables ($200-300 depending on length), and was well built if not particularly flashy.

The original was recently superseded by the Gemini3.0 which is what I ended up getting. It goes for $379 for a .7 meter length, or $529 for the 1.5m version. Certainly not a budget cable by any means, but build quality/materials are all commensurate with what you'll find in that price range (and beyond) from other brands. Plus, when you think about it, the Y style design actually requires twice as much cable, so it makes a little more sense in that context. Note that iFi also sells a Mercury3.0 cable which appears to be a more traditional take on USB audio (no Y split involved) but otherwise offering similar materials/design, for a substantially lower price. That may well be the way to go for the average user.

Upon opening the Gemini3.0 package, I realized why the name contains the "3.0" - this cable terminates in a USB 3.0 male type B at the DAC end. For those unfamiliar, this is a newer, slightly larger design than the typical USB 2.0 type B port you are likely accustomed to seeing on a DAC. There's a sort of backward compatibility here, in that a DAC sporting a USB 3.0 port can accept an older style cable, but not the other way around... unfortunately the vast majority of DACs out there do not have this newer style jack. So the Gemini3.0 is somewhat limited in this regard. Note that the USB Audio Class 2 standard is a totally different thing. We're strictly talking physical connectors when we talk about the USB 3.0 in this case.

As mentioned, the quality of this cable is extremely high. iFi lists it as "heavy OFHC continuous cast copper silver matrix" with HD Polyethylene and quad shielding, terminated with iFi's "Final" USB connectors machined from pure aluminum. The cable itself is a flat design, reminiscent of certain Analysis Plus speaker cables. The design features 3 "sliders" that can be adjusted to fit your system configuration. If your Data port and Power ports end up being very close, you can cinch the Gemini so it looks pretty much like a normal cable until the last little section. Or, if your ports have some distance between them, Gemini can split further down to accommodate that as well (making it more of a "V" cable if you spread them out far enough). The sliders themselves are described by iFi as being metal oxide ceramic filters, which silence RF noise by "detuning" the antennae formed by the cable. I didn't notice a difference in sound when changing slider positions, though I admit I didn't spend a bunch of time on that experiment (sounds incredibly tedious, but that's just me).



Of the many dozens of DACs (I've lost count) passing through my audio rack in the last few years, only a few had this 3.0 type B connector. Many, but not all, of the iFi DACs do - my most recent experience was the Pro iDSD which worked well with the Gemini3.0 in place. Other models include the excellent B.M.C. PureDAC and even better UltraDAC, along with the little AMI Musik DDH-1. Any model not using this newer style connection will require an adapter of some sort, which is not necessarily an ideal situation. But we'll discuss that further in a bit.


My first experience with the Gemini3.0 involved the iFi Pro iDSD DAC. I fed it with USB from my Euphony PTS music server which was powered by a Keces Audio P8 power supply. Initial listening was done with a Cabledyne Silver Reference USB, which is a very nice if more "traditional" USB cable in terms of design. I then swapped in the Gemini3.0 which drew power from the USB power output on the Keces P8 - a very useful component to have in this scenario.

After much listening, I thought I heard just the slightest improvement in dynamic grunt with the Gemini3.0 installed, plus a touch of added clarity in the treble region. The result is what I'd call improved realism, but we're almost splitting hairs at this point. The change is roughly on par with what you get by switching digital filters on a DAC - it can take strenuous listening to notice the change, and in some cases is just barely audible (depending on the DAC, the music, etc).

Next I swapped out the Euphony PTS for a Surface Pro 6 running Roon. Going back to the baseline performance using the Cabledyne Silver Reference, things took a considerable downturn. Imaging was less precise, soundstage flattened, and everything felt a dynamically compressed for lack of a better term. Treble suffered as well, with a sort of glassy feeling that I had not experienced with the Euphony PTS in the system. While still being enjoyable, the Surface-based setup was very clearly inferior - transports really do matter.

I then swapped in the Gemini3.0, using the same Keces P8 for power and Surface Pro for data. The difference was more substantial than I had anticipated. While not sounding as open and spacious as it did with the Euphony as transport, I still got a very respectable sense of where each instrument was coming from in the performance space. The treble shed its etch for the most part, which helped detail retrieval feel more natural. This sounded every bit like a high-end transport was involved, despite the pedestrian nature of the Surface Pro (from an audiophile perspective).

The Pro iDSD is unique in that it features built-in network audio streaming, and it happens to sound fantastic. If I wasn't a dedicated Roon user, I'd be more than happy omitting any external music server/transport and just stream directly. Since I do love Roon, I end up needing some external source to make that happen... which leaves me open for the Gemini option. If I mainly used my Euphony/Keces combo, I'm not sure I could justify the expenditure of the Gemini3.0 with this particular DAC - it did improve the sound, but by such a small degree as to probably not be worth the expense. But using a Surface Pro or, by the same logic, probably any regular laptop or consumer grade desktop, the Gemini3.0 plus the Keces P8 made a noteworthy difference with the iFi Pro iDSD.

I repeated these same experiments for the little-known $549 AMI DDH-1 DAC and got vaguely similar results, though with a different conclusion. In this case the cheaper device was effectively unable to resolve the change from quality standard USB to Gemini when using the dedicated music server. With the Surface Pro in place, I did hear worthwhile gains, but not enough to justify the expenditure: despite making the AMI device sound better than I had ever heard it, the ~$1100 for Gemini3.0 plus Keces P8 would be better spent on just getting a higher end DAC in the first place.

Moving decidedly up the chain in both price and performance, I brought out my ~$4k B.M.C. UltraDAC and repeated the experiment yet again. This time around the changes were more obvious in both cases - in favor of the Gemini all around. The dual-head cable really brought out a sense of musical ease, tonal richness, and rhythmic drive that only the best transports can hope to deliver. Very, very impressive performance.

I thought perhaps the UltraDAC would be immune to transport quality but the opposite turned out true... it really shows the flaws in a pedestrian source. This is likely due to B.M.C. intending users pair it with their pricey (and excellent sounding) PureMedia music server. In any case, with a budget allowing the purchase of a DAC in this league, it makes more sense that one might also be able to afford the Gemini/Keces add-on, as it really kicks things up a level or two. And to be perfectly clear - this goes beyond any difference I've heard involving a "standard" USB cable upgrade. While I think the Cabledyne Silver Reference USB is a superb USB cable and very likely on par with the more traditional iFi Mercury3.0 in terms of build quality and materials, there really does seem to be merit to the whole Y-split cable concept. I will definitely recommend it as one avenue of potential upgrade for folks already using a high-end, highly resolving DAC.


My main complaint about the Gemini3.0 is the termination on the DAC end. It just won't work with the majority of my devices. I did happen to have an adapter on hand but it converted to microUSB rather than standard USB type B. This allowed me to pair Gemini3.0/Keces P8 with the Massdrop Airist R-2R DAC, which despite its low price proved very receptive to the upgrade. In fact it may have made a larger difference than with any of the previously mentioned combinations. This DAC seems highly sensitive to incoming signal quality so I can't say I am surprised. Did the use of an adapter hold back its full potential? I have no way of knowing, but I was thoroughly satisfied with the resulting sound.

Browsing online for the appropriate adapter to convert to full size USB 2.0 type B was discouraging. Apparently that is not something many people need, so it is therefore not easy to find. I couldn't even find another example of the one I used with the Airist DAC - I picked it up a couple years ago and apparently they were easier to find back then. After browsing unsuccessfully for some time, I happened to notice iFi makes an adapter of their own.

Well, not exactly, but their iPurifier3 device happens to feature a USB 3.0 type B female jack on the input end, along with a more traditional USB 2.0 type B male plug on the other side. That's a perfect match to allow Gemini3.0 to work with the majority of DACs on the market. iPurifier3 is $129 so the price of implementing Gemini3.0 gets that much higher, though perhaps the iPurifier3 brings some benefit of its own to the chain (I have no experience with it).

That got me thinking - what does iFi want us to use for the power portion of the Gemini3.0? Surely they aren't counting on other solutions such as my Keces. This led me to browse their catalog again until I found the micro iUSB3.0, which appears to be the complementary device as it features dual outputs for power and data. Interestingly, that device ($429) plus the iPurifier3 add up to roughly the same price as my Keces P8. I can't comment on hypothetical performance from the all iFi system other than to point out that the multiple levels of filtering/regeneration/etc involved in the iFi trio may bring additional positive results... or not. These things seem very system dependent so it's hard to say for sure.


Bottom line, as far as I'm concerned: the iFi Gemini3.0 cable is an extremely high quality if slightly finicky take on the Y-split USB cable concept. I recognize that the company has almost universally embraced this newer style of USB jack on their own products, so it makes sense to find it here as well... but I still don't love the decision. I can't help but think how much more universal appeal the Gemini would have if it just featured a typical USB 2.0 type B solution.

That said, the results I got pairing it with my B.M.C. and Airist DACs were impressive enough to where I can't dismiss the Gemini3.0, even with the limitation involved. The improvement in those two cases even goes beyond what I've experienced with my favorite USB tweaks like the Wyred4Sound Recovery or BMC PureUSB, and far beyond that of even the best traditional USB cable upgrades. It's significant enough to where I do not ever want to use those DACs without the Gemini3.0 in the chain - anything else just feels second rate.

Stay tuned for my further iFi adventures: the iSilencer3.0 and DC iPurifier2 have been making the rounds in my system as well, and I'll add links to my thoughts on those once I finish writing them up.


-Addendum-

I just found out that iFi actually offers the Gemini3.0 with your choice of terminations at the DAC side - USB3.0 or the more common USB2.0 style. That makes my entire commentary above less relevant. I'm going to leave it for two reasons.

First, it shows how easy it can be even for a thorough reviewer to drop the ball on a potentially critical detail. It's a good reminder that all reviews, whether professional or amateur, paid/hobbyist/disgruntled customer/etc, are fallible. Always do your own research to verify the important details of any significant purchase.

Second, I don't think the termination choice is obvious enough. Most online shops selling the cable don't allow the customer to choose, nor do they all clearly picture that portion to at least provide a visual clue. So who knows which one they end up shipping. B&H Photo - with whom I am only affiliated as a frequent customer - is the main place offering the choice right there in the ordering menu. Unless you intend to use the iPurifier3, or your DAC has the newer style port, I'd be extra careful to order the proper version that works with your intended gear.

Having made my two points, I can now very enthusiastically recommend the Gemini3.0 cable for those wanting to squeeze the absolute maximum out of their USB to DAC connection. It's certainly not cheap, and makes things a bit complicated with the additional power supply, but the results are superb with the right setup.

I've been using a dedicated network attached storage, aka NAS, device for about 8 years now. I originally wanted one in order to easily share files between several different computers on my home network. Prior to that I had just used an external hard drive attached to my wireless router, but that wasn't a very robust or speedy solution for my needs. Once I got the NAS all set up, I discovered a myriad of uses which I hadn't even thought of before. Now I can't imagine living without it.

At the time I went with a Synology unit, only to discover it was kind of a lemon. All sorts of connectivity problems and after just a few months it died completely, forcing me to make a switch. I was ready to go with QNAP until a friend pointed me towards Asustor; I wasn't familiar with the line but have always enjoyed Asus products in general, so I gave it a go. Many years of faithful service later, the unit is still going strong, but I found myself needing more storage than the 2-bay design could offer.

After evaluating various current models, I again found Asustor to offer the most bang for buck. I chose their AS6404T 4-bay unit and am very pleased that I did. This thing is a great NAS and also offers some unique audio-related features which make it relevant for music enjoyment - to my knowledge, no other brand can do what Asustor does in this area.

As a NAS, the AS6404T is very competitive. $549 gets you a 4-bay device with superb build quality, a relatively potent (for a NAS) Celeron J3455 quad-core CPU, and a full 8GB RAM as standard. In that price range one typically finds far less RAM and/or an ARM-based processor which isn't anywhere near as powerful as the J3455. You generally want your CPU above a certain threshold in order to comfortably handle more advanced features like video transcoding (or music playback with a large library). While Synology and QNAP have finally launched a few reasonably competitive devices, there is still usually a compromise involved in CPU or RAM... not to mention the audio-related connectivity which pushed me towards Asustor.

(I'm using stock photos here, my 6404T lives in a messy media cabinet right now and nobody wants to see that)

The 6404T is very full featured: front panel LCD, dual Gigabit Ethernet with Link Aggregation, a pair of rear panel USB 3.0 ports plus another up front, a USB 3.0 Type-C port, an HDMI 2.0 output, and a Toslink jack as well. This means it can do all the usual NAS duties but can also work its way into an audio system like no other NAS I've encountered.


I set mine up with 3x 8TB Western Digital Red drives in a RAID5 configuration, plus a 250GB Samsung 860 EVO SSD for caching purposes. I don't know how necessary the cache drive really is but with SSD prices so low these days, I just went for it. My choice of RAID5 gives me 16TB worth of storage plus a decent level of redundancy - I have everything backed up externally as well so I'm not worried about it. I know some of the newer devices from Synology and possibly QNAP give 4-bays plus an M.2 option for the SSD cache... that would be nice, but it wasn't a big enough factor to sway me.

Asustor calls their operating system ADM for Asustor Data Master. I find it competitive with Synology and superior to QNAP, though obviously they all have their own ups and downs... and they are all constantly evolving from month to month. ADM is simple to use and has quite a few useful apps available (well over 200 of them by my count), and is vastly more developed than you'll find using a budget device like Buffalo or Zyxel. In my experience it is generally up there with Synology's DSM system which many consider the industry leader. Again, as a regular NAS, I find the Asustor very competitive overall.




I'd like to shift the focus to music playback as that's why this review is relevant to HeadFi in the first place. Store your music on the NAS, connect it to your audio system via Toslink or USB or HDMI, and use one of the several available playback apps to control your music. It works surprisingly well in my experience. Depending on the app, you'll either use a phone/tablet or else a computer (via web interface) to interact with things, and the experience is surprisingly full featured. And the sound quality? Excellent.

Asustor NAS devices support external USB DACs. Since ADM is based on Linux, most DACs work well, but I'm sure there are exceptions. I have yet to personally find a DAC that doesn't play any music at all, though certain models have issues with DSD. As with other Linux-based devices, sometimes the thing requires a reboot before it plays well with a newly connected DAC. A friend tells me his old NuForce uDAC (maybe uDAC 2 or 3?) won't even do CD quality playback but I can't confirm that. In the case of a USB connectivity issue - or just an older DAC without a USB input - the Toslink connection comes in handy. It does hi-res PCM up to 192kHz assuming the connected DAC can handle that (some Toslink receivers top out at 96kHz). Or, if you wanted to use an A/V receiver or one of the few DACs with HDMI inputs (the NAD M51 comes to mind), the HDMI output is an option as well. Between the three different outputs, there should be something for everyone.

On the software side, again we encounter multiple options. The Hi-Res Player app is the first one I tried; it has a nice interface, handles standard CD quality FLAC as well as high resolution PCM (24-bit/384kHz) and DSD playback (via DoP with a USB DAC). It can be controlled via web interface or theoretically by any MPD control app such as DroidMPD (Android) or Soundirok (iOS). I say "theoretically " because I have yet to figure out the configuration settings needed to get those apps talking to Hi-Res Player. Then again I haven't really tried very hard as I quite enjoy the web interface using my Surface Pro. The only issue I find is a limit on library size - I have over 5TB worth of lossless music on the NAS and Hi-Res Player seems to give up rather than properly scanning it all. If I copy a portion of my library to another folder and point the app there, it works just fine, but I don't know where exactly the limit might be. In my experience a lot of apps have particular issues like not working with certain special characters (the & sign for example) or not handling sub folders which are nested too deeply. I haven't fully explored this to figure out what Hi-Res Play dislikes or if it truly is just a size limitation.


Next up is AiMusic, a first party app from Asustor. It has a simple yet fairly attractive interface which allows for intuitive operation - 2 minutes in and I felt like I had been using it for years. Again I had issues with the app showing my entire library but I can't imagine the developers had 100,000+ lossless tracks in mind when they built it. When I switch to a smaller library, it all works well, including proper album art. This app also allows for easily streaming the library to my phone, giving me access to my music from anywhere in the world.



The final player to mention is SoundsGood, which I'm happy to report does support my entire library. I use the web interface to control it and am quite pleased with the results. I later learned that AiMusic actually uses SoundsGood as the playback engine so I have no idea why the web interface shows my whole library yet AiMusic doesn't. Documentation on this (and most other apps) is fairly sparse - it took me a while to figure out how to change output settings from HDMI to Toslink to USB, as the actual button in the app looks a bit different than what they show on the Asustor web page... and it requires a double-click to open, which is not documented anywhere.


Browsing through a massive library is just a tad slower than I'd like, but still very reasonable overall. Using a more reasonable library feels totally smooth and responsive. For someone not accustomed to a superior UI such as Roon or a well-configured JRiver, this is a perfectly fine way to handle all music playback. Even as a rabid Roon fanatic I still find SoundsGood to be perfectly satisfactory in the room where my NAS lives - which is handy since I don't have a Roon endpoint in there at the moment. I have the NAS connected to an iFi nano iDSD Black Label which typically drives custom IEMs directly... it's a great little system that sounds very nice indeed. The NAS itself is on the quiet side but if I was using open headphones the faint hard-drive activity noise might become a distraction when playing certain music. With closed headphones or IEMs (or speakers), or with the NAS in some kind of cabinet/enclosure, it's not an issue.

Speaking of sound, I still can't get over how impressive this thing sounds as a transport. Whether running USB or optical, I can pair it with an extremely high-end DAC without thinking twice. Despite not being a "dedicated audiophile device", I really don't hear any drawbacks. It's better than all the laptops I have in my house, and better than my Surface Pro as well, with excellent imaging and fine microdetail. This is likely due to the Linux-based OS having very low overhead, but still... there's no fancy power supply or shielding here, and with 3 hard drives spinning away it doesn't really come close to best practices for a transport. Regardless, I really like what I hear. Is it perfect? No, I like the SOtM sMS-200 better for overall tonal richness and dynamic heft, though it's surprisingly close overall. That's not bad company to be in.

I got a little crazy and added an iFi iSilencer3.0 between Asustor and USB DAC. With some pairings I noticed a worthwhile improvement, with imaging becoming even more focused and treble sounding very slightly more natural. In other cases there wasn't any change at all. It really depends on the DAC being used. Best case scenario was that I'd call it just a hair behind the SOtM sMS-200, which again is what I consider a very high performance transport. I was all set to try out the iFi DCiPurifier2 to hopefully close the distance when I realized the Asustor draws 7.5 A while the iFi only supports 3.5 A - I decided against it. Still, for a general purpose computing device, the sound produced is outstanding - I used it to feed a Wyred 4 Sound 10th Anniversary DAC ($4,500) paired with a Cayin HA-300 tube amp ($4,000) with no complaints at all.


I do have to mention the main drawback compared to Synology or QNAP. That being the user community, which for those two brands is thriving but for Asustor is sparse at best. If you need configuration help or have some questions/concerns, you are typically better off dealing with Asustor support directly. The community just isn't there in this case. Asustor support is responsive but I still envy the community-driven nature of the Synology ecosystem. That means Asustor is probably more appropriate for users who have at least some knowledge of computers and networking, who can figure out the majority of things on their own.

One example of this is Roon. A friend runs Roon Core on a Synology DS918+ which sports the same CPU and RAM as my 6404T (but his cost more and he had to add another stick of RAM to hit 8GB). Roon feels quite snappy on his setup, despite using on a relatively slow older Crucial SSD for the database - probably due to the overall library size being relatively small (he relies on Tidal augmented by about 100GB worth of hi-res favorites). He tells me the install was a breeze. I can probably get Roon Core up and running on my setup but it would require working with Docker or Virtualbox and I'd have to figure it out myself. I probably won't bother as my huge library seems like too much for the hardware, but it would be nice to have the option available in a simple process like Synology does.

Despite that, I feel that I still haven't scratched the surface of what the 6404T can do. I intend to mess with Plex now that it has Tidal integration, to see how well it runs in this context. There's Nuclear Music Player which appears to handle web streaming from Soundcloud and many other sources. Then there's Spotify, Amazon Prime Music, Twonky, BubbleUPnP, and various other DLNA/UPnP options to mess with. And that's just the music-oriented stuff - it already runs Emby Server for movie streaming, syncs with Google Drive and OneDrive, and a plethora of other mundane functions that I'm forgetting right now.

Yes, most of this could be handled equally well by another NAS (probably at a higher price though). But the audio capabilities are what really make Asustor special in my opinion. If I'm going to run a NAS anyway, why not make it double as an unexpectedly nice transport? Because, as odd as it may seem, that's what the 6404T sounds like.

EDIT - March 2019

Roon has arrived! Thanks to enthusiast/developer Christopher Rieke, Asustor now has an app for Roon Server. Using a 256GB Crucial SSD for the Roon database, the AS6404T performs surprisingly well. Even with my nearly 10,000 track library, it feels as responsive as any NUC or standard PC I've used for the job.

I can upsample to 384kHz PCM as well as DSD128 without issue. DSD256 is a bit of a stretch (sometimes it's fine, sometimes things stutter), and I haven't done any multi-room or EQ tweaks which can take a lot of CPU horsepower. But for what I'll call "standard" use for a single listener, the Asustor is definitely adequate.

This pretty much seals the deal for me - the AS6404T now does everything I could possibly hope for, and I'm thrilled that I chose it.

Who makes better cars - Toyota or Lexus? How about Honda versus Acura, or Nissan against Infiniti? Of course, these are silly comparisons, as Lexus, Acura, and Infiniti are simply the luxury divisions of their respective manufacturers. The cars themselves often share a basic platform, with the luxury version shooting for more style, features, and brand cache. This succeeds or fails on a case by case basis but I can clearly see the point of it - the "Lexus" marquis allows Toyota to sell LS-series sedans for $75K+ when nobody would accept a Toyota-branded sedan in that price range, however nice it may be.

The audio industry occasionally does a bit of this as well, though it usually goes in the opposite direction. Established brand YBA went downmarket with their Audio Refinement line, ostensibly to reach new customers who couldn't afford their normal gear. Same thing with Raidho speakers and the more affordable Scansonic models, or Cary with their Audio Electronics line of gear (now defunct, as far as I can tell). All three of these examples had well-regarded designers and established firms putting out gear that just wouldn't fit under the original brand banner.

The best example I can think of going in the upward direction is German firm Lake People GmbH. Despite making studio-oriented equipment for several decades, the name still didn't carry much weight in certain regions; including the USA. So the company launched Violectric roughly a decade ago as a way of branching out into the high-end consumer market. Their line of headphone amplifiers, DACs, and preamps has earned many accolades, with the V281 serving as my reference headphone amp for the past several years. Most folks seem pretty comfortable considering Violectric as "high-end" gear, whilst more affordable offerings sporting the original Lake People branding reap the benefits of improved name recognition. It's win-win.

What to do when you want to move even further up market? One idea is to launch yet another brand name specifically encompassing the best of the best. That's Niimbus, the "Ultimate" series from designer Fried Reim of Lake People/Violectric fame. This is the statement line of products, with pricing - and hopefully performance - to match.

At the moment, Niimbus is comprised of just two upcoming products - the US4 headphone amplifier, and the US4+. One or more DACs will come later. Both headphone amps share the same core components, with the Plus going beyond in terms of pre-amp functionality and a few other bells and whistles. I've been spending time with a prototype US4+, so that's what I'll be discussing. I don't yet have a specific date for when these will be available other than "pretty soon". Also keep in mind that the appearance may end up changing - probably by a small amount, but there's a chance it may be substantial.



The very first thing to mention is the pricing - it isn't finalized yet, but I expect somewhere close to $4,000 for the US4 and $5,000 for US4+. Give or take a bit. That puts the Niimbus line up there with some of the most expensive headphone amplifiers on the market.

I'm not going to go too deeply into the pricing aspect. It simply is what it is. No doubt many can't afford it, and some will even be downright offended that it exists. I can absolutely understand that point of view.

I'll just point out two things. One, the US4+ is a very complex device. Lots of quality parts, and lots of labor to assemble it. Two, Violectric is based in Germany, and does all their assembly in-house. CEO Fried Reim has consistently upheld the view that he wants to pay his workers a respectable wage - a practice which is surely honorable no matter our thoughts on final product or pricing. It seems to have the added bonus of delivering superb quality control - you very, very rarely hear of a malfunctioning Lake People or Violectric device. Happy workers apparently do better work.

Offloading production to China would certainly allow for significant price reduction. As would a direct-sales business model. The company has always used the more traditional setup with regional distributors who no doubt require their cut. Again, we can argue about the merits of each approach, but in the end the Niimbus amps cost what they cost, period. Some people will find it absurd, a few will buy it without hesitation, and most will be somewhere in the middle.



So just what to we get for that cash outlay? In the case of the US4+, that would be a balanced solid-state amplifier representing over three years of development, which doubles as a superb (if somewhat light on inputs) preamp. Inside the case we find a massively beefed-up design only partially reminiscent of already excellent V281. No longer constrained by the V281's "shoebox" form factor, this larger enclosure houses over 60 transistors, twin shielded 25W toroidal transformers flanked by over 50,000uF worth of Nichicon filtering caps, a highly advanced volume control solution, and extensive protection circuitry. The result is an amp capable of swinging 32V into 600 ohm loads, whilst topping out at 7W per channel at 50 ohms.



Backtracking to that volume control implementation for a moment; the V281 had an optional relay-based solution featuring 128 steps in .75dB increments. It added nearly $600 to the price, and made a small but noticeable improvement over the base-model's Alps RK27. Niimbus amps will not have options. The sole offering is an exotic 256-step affair (in .4dB increments) based on reed relays - the contacts are situated in a sealed glass tube which is filled with gas and operated magnetically. This solution is exceedingly precise, with perfect channel matching at all levels and plenty of steps for fine tuning. It has the added bonus of being nearly silent in terms of physical operation. Some folks with the relay-equipped V281 complained about the audible clicks when making adjustments, though I personally never found it bothersome once I knew what to expect. The Niimbus volume solution is much less audible though - on a quiet day, with your ear next to the amp, you can hear just a tiny bit of noise, but that's about it.

Interestingly, the focus here seems not on additional power - though there is an increase - but rather the decrease of noise. Going back to the Violectric V200, and many other Lake People/Violectric models, the amplifier gain was 8dB. Balanced operation on the V281 adds 6dB for a total of 12dB gain. But when we get to the Niimbus, amplifier gain is -4dB... signals passing through the amp are actually lower at the output than they are at the input. In this way, it could be said that Niimbus acts more like an impedance converter than a traditional amplifier with gain. And when we add the 6dB for balanced output, we end up at a final value of 2dB - which is 10dB less than balanced out on V281. A 10dB reduction in noise is remarkable considering the V281 is already an extremely quiet amp. Niimbus continues the now-familiar pre-gain adjustment options, expanded in functionality over the V281, so final gain can be set to match very quiet or very hot sources while keeping plenty of travel in the volume knob.


Review System, or "It's Complicated"
I wanted to keep this simple. I really did. Short and sweet, just do a bunch of listening and report on my thoughts. But one thing led to another, and things kept snowballing until I had a ridiculous collection of gear involved. This is almost certainly the most complex evaluation I've ever done for a single product. In an attempt to salvage some small portion of brevity, I'm going to limit my comments to the Niimbus amp itself rather than the associated source gear. I may eventually write up my thought on the DACs involved, but I don't know when that might happen.

It all started like this: my initial listening showed the US4+ as being startlingly revealing to the signal chain. So much so that I decided to create a dedicated setup to quickly switch back and forth between three of my favorite DACs. Listening to the Niimbus seemed to give me just as much insight into my source as it did the amp itself, so I didn't want to rely solely on one DAC - however nice it might be.

At first, my simple plan involved multiple SOtM sMS-200 devices (I own a bunch), each driving a different DAC, feeding into the trio of analog inputs on the Niimbus. I could then switch back and forth on the fly.

The multiple SOtM solution didn't work out very well, for reasons I won't get into here. Instead, the chain ended up being more complex - Euphony PTS music server, USB out via BMC PureUSB1 active cable to a Matrix X-SPDIF 2 DDC, then AES/EBU linking the Matrix to a Titans Audio Lab Helen. The Helen (review forthcoming) is a fantasticbuffer/reclocker which has the added bonus of providing simultaneous outputs in AES, BNC, coaxial, optical, and HDMI I2S formats. This allowed me to feed several DACs at a time with impeccable signals. The Euphony server and Matrix DDC were powered by a Keces P8 linear power supply while the Helen used its stock PSU (which seems to give the best results).



On to the DACs. At first I went with a trio of modern favorites - Resonessence Labs Mirus Pro Signature, Wyred4Sound 10th Anniversary Limited Edition, and ModWright Oppo 205. Later I rotated through some classics - Assemblage DAC 3.1 Platinum, Sonic Frontiers SFD-2 MKIII, and a Stax DAC-Talent. I also used a pair of modern R-2R DACs at extreme ends of the price spectrum - the rather expensive Metrum Pavane Level III, and the budget Massdrop Airist RDAC. Factor in the miscellaneous other nice DACs on hand such as the Exogal Comet Plus, Cayin iDAC-6, iFi Pro iDSD, Yulong DA-9, RME ADI-2 DAC, and BMC UltraDAC, all of which had at least a bit of play time with the Niimbus.... and you can see how much listening was done.





Using any decent headphone allowed the Niimbus to very clearly delineate between these devices. Level matching was tricky and I confess to not being as precise when dealing with the vintage DACs. But in general, I felt like I learned to identify each distinct sound signature far better than I ever had before. I even gained new insight into gear I've logged thousands of hours on, such as the Assemblage. Some existing opinions were confirmed while others had to be reformulated based on this experience. Again, I may put down my thoughts on these DACs at some point, but the main focus here is on the Niimbus.

For headphones, I used a similarly absurd collection - Abyss Phi CC, Audeze LCD-4 and LCD-2, HiFiMAN HE6, HE1000 MKI, and Susvara, Sennheiser HD58X, HD650, and modified HD800, modified AKG K812, MrSpeakers Ether C, Ultrasone Edition 12, Focal Utopia and Elex, Sony Z1R, 64 Audio A18t, Empire Ears Zeus XR ADEL, UERM, Noble K10, and a bunch more that I won't bore you with. Most of these belong to me but a few, such as the Susvara and Abyss, were borrowed.



I also brought in various expensive amps to survey the competition - again, some owned and some borrowed. These included the Eddie Current Balancing Act, SimAudio 430HA, Eleven XI Audio Formula S, Auralic Taurus mkII, Woo Audio WA5LE, iFi Pro iCAN, Questyle CMA800R monoblocks, ALO Studio Six, Violectric V281, DNA Stratus, TTVJ Millet 307A (precursor to the Apex Pinnacle) and Pass Labs HPA-1. While not quite representing every single high-end amp on the market today, I feel this is an adequate sampling of end-game options - certainly enough to give the US4+ a thorough workout. Unfortunately I only had a few of these on hand at a time, so I don't feel qualified to fully document my thoughts on these models and how they relate to one another. I also messed up and forgot to document the tubes being used. The owners provided their favorite glass and I did not have time for tube rolling. This means the resulting comparisons must be taken with a grain of salt, as they only represent one possible take on the character of each tube amp.

For those who care about little details: rounding out the system was an Equi=Core 1800 balanced power conditioner, Cabledyne Silver Reference AC cables, and a variety of quality interconnects/digital/headphone cables from Cabledyne, BetterCables, C3 Audio, Effect Audio, Toxic Cables, and Moon Audio. Listening was done in balanced mode whenever possible. I do have a nice adapter from Toxic Cables, converting 4-pin XLR to 1/4" for those amps not equipped with balanced out.


I haven't done the math, but this is a cumulatively absurd collection of gear. I just wanted to point that out. Though the Niimbus itself has a substantial price tag, it's certainly not alone - plenty of these amps and DACs are priced in the same region or beyond.



LISTENING
I never planned for this to spiral out of control the way it did. Had I known from the start what this project would lead to, I would have carefully and methodically put each component through its paces, and chronicled everything in great detail. I also would have grabbed a bunch more pictures, even if they were ugly (this was a really messy few months for my system). That project would take an incredible amount of time, which I simply don't have. As it stands, I'll just be throwing out my somewhat disorganized thoughts, with snapshot comparisons, in hopes that they lead to a decent understanding of the Niimbus character. If you have a particular comparison you'd like to know about, feel free to ask, but I can't guarantee I'll have a good answer. If you don't feel like reading a novel (and I don't blame you), just skim to the section you want - the amplifier names are in bold for easy navigation.

Having said all that - the Niimbus US4+ absolutely belongs in this field of excellent amps. To my ears it handily outperforms most of the solid-state competition, and puts up a valiant fight against the best tube-based models out there. First, the solid-state options:


*The Auralic Taurus MKII ($1,900) sounds comparatively artificial and shouty, lacking subtlety and nuance throughout the spectrum. I don't at all find the Taurus overly bright in isolation, but that word appears several times in my listening notes when compared directly. There isn't a single headphone where I would choose Taurus over Niimbus.

Keep in mind, the Taurus is a very nice amp (Tyll and I both used it as a reference for some time), and for many people would represent a suitable end-game solution. Think of it as an "entry level" Porsche Boxster which is a thrilling vehicle yet can't keep up with the base model 911, much less the Turbo or GT3 variants.

*The Questyle CMA800R monoblocks ($4,000/pair) come off as comparably thin, lacking both bass depth and midrange body. Niimbus is significantly more palpable. Treble clarity, a major strength of the Questyle duo, is even better with the US4+, having a more natural, convincing feel. The only area where the monoblocks compete is the holographic soundstage. Driving an HD800 or K812, the Questyle amps do keep up with the Niimbus in that particular area. In many other aspects they feel a bit sonically compressed, for lack of a better term. Niimbus also takes a major lead when driving most planars, where the CMA800R combo feels comparatively underpowered and therefore dynamically underwhelming. Again, the Questyle offering is very competent in its own right, yet totally outperformed by the Niimbus (I'm going to stop saying this now, but keep it in mind for most of these amps).

I also found myself very much disliking the dual-mono nature of the CMA800R, with a separate volume knob for each channel. When the DAC has a quality onboard volume control then it's no big deal, but without that things get tricky. I guess I had forgotten how much of a hassle this can be.

*I had never heard the Eleven XI Audio Formula S ($5,500) prior to this project. The owner swears by it when paired with the Abyss Phi CC, which he also provided for this shootout (thanks again!). This particular example had the beefy (optional) matching PSU that seemed to weigh more than the actual amp itself. The amp with PSU is priced very closely to the Niimbus US4+, making it a natural competitor.

It's absolutely true that the Formula S excels with the Abyss; apparently the amp was designed with those specific headphones in mind. That particular combo is indeed breathtaking in several ways - particularly the crushing dynamics swings and bass performance which feels more like listening to speakers than headphones. Detail is nowhere near the same level, but with a good amp pairing I find it acceptable if not amazing. As most people know, fit is key with these headphones, and thankfully my big head seems like a good match. I remember having trouble when the original Abyss first launched but this time around things work very well - it still feels a bit weird, but isn't uncomfortable at all.

The Niimbus performs almost as well with Abyss Phi CC. It falls behind by just a hair in terms of layering - the difference is so small as to be hardly noticeable most of the time. Does that mean the Formula S is a better amp? Not really. The thing is, when I use Formula S with headphones from Focal or Sennheiser, it doesn't perform at that same level. It never sounds bad per se, but with most dynamic headphones I feel it falls short of sounding like a $5k amplifier. In fact it probably ranks down there with the Auralic for least impressive solid-state amp when using Utopia or HD800 or K812. Terrible? Not in the least. But it certainly doesn't sing the way it does with Abyss, and to a lesser extent, HE6 and Susvara. It just doesn't seem as refined as I would like - the midrange in particular sounds a bit dull, and transient response is not as snappy as I expect from an amp of this caliber. I don't exactly know why this would be. The Formula S puts out around 6 watts into 16 ohm loads, while the Niimbus does 7 watts into 50 ohms. I doubt it really matters either way - that's far more than needed for most any headphone.

Ultimately it seems the Formula S really excels with planar headphones. It does do quite well with certain dynamic headphones, like the Sony Z1R and Ultrasone Edition 12, but it mainly shines with difficult loads - Susvara, Abyss, HE6, and even the less difficult to drive LCD-4. Despite its prowess, I still end up preferring the Niimbus with everything but the Abyss. The Susvara in particular has more cleanly rendered transients and superior low-level detail when driven by the German amp. LCD-4 is a close call but tips slightly towards the Niimbus due to more nuanced bass texture, by about the same margin as the Formula S takes the prize with Abyss. HE6 is again a very close call but after careful listening I feel Niimbus has more believable treble.

In the end I would only recommend the Formula S over the US4+ if someone listened exclusively with the Phi CC and was certain they wouldn't stray from that product - which seems like a pretty bold decision. Though that combo issomething special, I still like variety in my headphone listening, and the Niimbus delivers that to a much greater degree.

*The Pass Labs HPA-1 is a superb amp. I'm not sure why it doesn't get more love at HeadFi. Perhaps its the lack of balanced drive which stops people from taking it more seriously? I don't know, but to my ears it remains among the absolute best amps in existence.

Niimbus gives it a run for its money though. The biggest strengths of the HPA-1 are its amazing treble clarity and wide open presentation. That's where it beats the Violectric V281, which is a touch more dynamic and punchy but not as refined. The Niimbus splits the difference - it's more dynamic than the Pass, but just as articulate and nuanced, if not even more so with certain headphones.

I'd call it a fairly even match with many headphones, but when you get into more difficult loads the Niimbus takes the lead. Susvara and Abyss don't quite hit their full stride with the Pass - they are very, very good, and I would certainly be happy with either.... until I switch to the Niimbus and discover both headphones have even more performance to be unleashed. In comparison the Pass is dynamically flatter and more "gray" sounding, as well as less tonally rich through the midrange. The same thing generally applies to the LCD-4 and HE1000, and even the Ether C to a smaller degree. All sound great with the HPA-1, yet all show improvement with the Niimbus.

With most dynamic headphones the differences are far less significant. HD800 does well with the added solidity of the US4+, whilst both Elex and Utopia seem to prefer the Pass for reasons I can't really put my finger on. Both amps do sensitive IEMs very well, which is rare even in this field of flagship amps - the 64 Audio A18t performs right up there with the absolute best full-size headphones when driven from either amp.

I do find the single-ended nature of the Pass to be somewhat limiting depending on the DAC involved. For example, the ModWright Oppo 205 sounds clearly better via XLR connection, as does the vintage Sonic Frontiers. In both cases, using the Pass Labs amp means "settling" a bit, rather than hearing the full potential of the source device. This may or may not matter depending on the DAC involved. On the flip side, the price difference is certainly something to consider, and the Pass amp is obviously more recognizable in both appearance and brand.

*The iFi Pro iCAN ($1799) is the least expensive amp used in this comparison. In some ways that shows - it's smaller, lighter, and less physically imposing than any of the others. But it's also a very enjoyable amp which earned high marks when I reviewed it at InnerFidelity a while back. It's got more options for sound adjustment/enhancement than anything else in this group, which makes for an interesting (and somewhat difficult) comparison.

Despite being very different in terms of features and focus, the Niimbus does remind me if the Pro iCAN in the sense that it is universally competent. While the iFi is sort of a "jack of all trades, master of none" in terms of the basic amp itself, I still find it very likable. It doesn't have any glaring errors in presentation. While not competing with the best amps out there, it falls short due to being merely very good rather than great in most areas. Other amps stumble by showing some obvious flaws which keep them in the lower tier, whilst the iFi does everything fairly well if not quite exceptionally. In that way it reminds me of the Niimbus, which seems to do everything superbly even if it gets bettered in a few specific areas by certain amps.

Of course, the comparison falls apart when you factor in the multitude of sound tweaking options on the Pro iCAN. If I say the US4+ sounds like an improved Pro iCAN, that's an almost meaningless statement - the question then becomes "what settings"? There are actually some instances where I can make the iFi my favorite amp in this whole group, when focusing on a specific DAC/headphone pairing and playing certain tracks. Again, that makes it nearly impossible to really compare, so I won't waste any more time on it.

*I don't really care for the SimAudio 430HA ($4,300 with built-in DAC module). In fact I once completed a lengthy and detailed review as to what I found lacking, only to have it rejected by my then-editor (not Tyll) as being too negative. I made numerous changes to soften the blow but apparently it still wasn't enough, so the review was canned (you can read the edited/nicer version here). My entire point was that the optional DAC sounded (surprisingly) great, the preamp functionality was awesome, but the headphone amp itself fell short. I stand by that assessment to this day, despite the disagreement of several friends.

The 430 can drive pretty much any headphone. It has a silent background for IEMs. It has an excellent volume control scheme which is very precise and feels great to use. And yet, the actual sound of the amp is just slow and uninvolving. Talk about a wet blanket all over my music. The Niimbus is so much more dynamically alive, with superior timbre, more convincing imaging, and a sense of "rightness" which I just find obvious. To my ears, there really is no comparison at all.

Interestingly enough, I actually think the more affordable SimAudio 230HAD sounds better in terms of amplification, and would steer folks in that direction if they simply must have a SimAudio product for their headphone needs. Despite my negativity, I've been a SimAudio fan for quite a few years now and would love to see them deliver a "proper" reference headphone amplifier. Ideally it would end up sounding a lot like the Niimbus US4+.

*The Violectric V281 ($2,939 with relay-based volume option) has long been one of my favorite solid-state headphone amps, tied with the Pass Labs HPA-1. It pairs amazingly well with every headphone I've ever thrown at it, with the caveat that it really needs balanced headphones to extract the full potential.

Since Niimbus shares some design aspects with the V281, you would not expect the general sound signature to deviate by much. And you'd be correct in that assumption. The basic presentation is definitely from the same family - robust, textured low end performance, weighty tonal balance, precise imaging, stunningly clear mids, and delicately balanced treble. Again, the V281 is a superb amp which is by no means hindered by the existence of the Niimbus line.

That said, I do hear some differences when switching back and forth. I'd start by saying the US4+ has bass performance both calmer and richer than the V281. A contradiction? Not really. It's effortless. Bottomless. Thunderous. Unflappable. All at the same time. Whether playing bombastic large scale orchestral works, Felix Hell pipe-organ, Gary Karr double-bass, or Edit-Select's Phlox, the Niimbus brings a sense of authority which V281 doesn't quite match. This can be heard on Keeno's Futurist, where the track "Bleary-Eyed" incorporates rapid thumping kick-drum strikes along with a simultaneous rolling bassline that really plumbs the depths. Niimbus handles both aspects with more control and resolution than any amp I've heard, including the V281 (which already performs at a very high level). It's really sort of breathtaking when the right headphones are involved.

The rest of the spectrum sounds more open and refined via Niimbus. It allows me to hear bigger jumps in quality when going from a good DAC to a great one, then all the way up to world-class level. It's also more likely to showcase the improvement brought by tweaks such as the Wyred4Sound Recovery reclocker (depending on the DAC, obviously). Again, V281 is exceptional in its own right, but the US4+ just scales higher, bringing with it new revelations into my playback chain.

Is this "in your face obvious"? Not always. When using the HE1000, Elex, Ether C, or LCD-4, the difference is fairly negligible. But with HD800 I notice it more. Susvara? Abyss? HE6? Yep, there's definitely a considerable improvement to be had. Interestingly, it doesn't seem to be merely a power difference. The easy-to-drive modded K812 really prefers Niimbus, as does the Sony Z1R, both seeming to appreciate the Niimbus' treble refinement and iron-grip more than its increased output. These are headphones I don't even like with certain amps, but here they sound very enjoyable.

Sensitive IEMs are another area where Niimbus outdoes the V281. Remember I mentioned the 10dB reduction in balanced mode? It's enough to make nearly any IEM present a silent background even via balanced output. I realize that most balanced IEMs use a 2.5mm connection or the newer 4.4mm style, but adapters for 4-pin XLR are easy to come by. Running a world class custom IEM like the 64 Audio A18t via Niimbus is really something special. The exacting nature of the volume control is very welcome, and the superbly linear presentation is just beautiful. Even still, some models are so sensitive as to still exhibit a bit of hiss - certain IEMs from Empire Ears, JH Audio, and particularly Campfire Audio seem bound to hiss a bit no matter what you plug them in to (but I'm sensitive to hiss anyway). In those cases single-ended mode may do the trick, with minimal sacrifice in SQ.

In the end, the Niimbus is either a minor step up over V281, or a large one, depending on the headphones involved. And the better your upstream gear, the more noticeable the improvement will be. Is it worth the money? There's no way I can answer that question for you. I'll say, without a hint of condescension, that for many people the Niimbus, V281, and even the V280 might be overkill anyway. One of the "lower end" Lake People amps may very well make more sense in terms of value per dollar. But for a statement-level experience, the Niimbus does deliver the goods across a wide variety of headphones. Make of that what you will.



That concludes the solid-state comparisons - now for the tube-based alternatives. As I said, these require a definite grain of salt due to my unfamiliarity with the tube configuration. While each amp had expensive glass which the owner had settled on after much trial and error, there's nothing to guarantee their favorite combo is the one I might like best. Indeed, many of these impressions conflict with what I've heard from these models in the past. Still, there is some value in the comparisons regardless. Note that I'm only listing stock prices here, knowing full well that at least a few hundred dollars will be required for quality tubes.


*First up is the ALO Studio Six ($4,100) which I believe came equipped with the upgraded teflon caps. Pricing after upgraded caps and tubes ends up being similar to the Niimbus. I'll be honest - I haven't historically liked this amp. I've heard it several times and thought it sounded slow, a bit veiled, and overly syrupy, yet lacking in the fun factor that sort of signature can bring when done right. This particular example admittedly sounded better, so either the cap upgrade or a wise choice in tubes (or perhaps both) made the difference. Still, I find it only marginally superior to the Cayin HA-1A MK2 which sells for $999. With the right tubes, I can come fairly close to replicating this type of sound with the Cayin, for roughly 1/4 the cost.

The Niimbus is quite a bit more neutral and resolving than the ALO. It portrays a sense of orchestral scale far more convincingly. It has superior bass texture, quicker transients, and significantly better treble clarity. About the only things the Studio Six does better is certain female voices - which can be rather beguiling with the right headphones - and a bit of euphonic treble coloration (not to be confused with treble control, where the Niimbus easily wins). I suspect many of the higher-end Audio Technica headphones would do great on the Studio Six - I'm thinking W1000Z, W3000ANV, and the W1000X in particular. I also think other potentially zingy headphones like the Fostex TH900 might be a good match. And I did have a good time using it with the stock HD800 as well as the Edition 12, both of which benefit from the darker/smoother presentation.

Still, I consider the Studio Six something of a novelty at best, and can't comfortably recommend it in this field of outstanding challengers. The Niimbus is easily superior to my ears.


*Woo Audio's WA5LE ($4,900) is an amp that I find very aesthetically pleasing. Just sitting there on my audio rack, I already have a strong appreciation for the device. Unfortunately the sonic performance does not live up to the amp's good looks.

This is very clearly a more colored presentation than the Niimbus. It has a lushness to the midrange, a sort of bloom or glow that is undeniably fun in its way. I can hear why some people fall in love with this amp. It brings a sense of fullness and body to headphones like HD800 which can lack a bit of soul from more neutral amps. Imaging accuracy is also excellent, despite the soundstage being only moderately large compared to the best amps in this shootout.

Bass control is lacking though, and treble is inoffensive at best, boring at worst. There were times when I felt resolution was quite good, but the very next track would show obscured micro-detail and underwhelming transients. I just couldn't get a consistent performance out of this thing.

Note that this was the more recent version with the "premium" upgrade from the factory. After tube upgrades, that probably makes it more expensive than the Niimbus. The Woo initially feels pretty dynamic but the somewhat gray background and undefined bass impact really put a damper on that in absolute terms. Again, I much prefer the Niimbus for all but a few very specific configurations, and even then I think you can do better with one of the other tube-based offerings in this roundup. I do seem to recall hearing much better sound out of a WA5 several years back, so this may just be a poor choice of tubes for my preferences.

*The DNA Stratus ($3,000) is also quite attractive in its own unique way, like a slab of cotton candy with tubes and transformers sprouting from the top. It doesn't match a single thing in my audio rack, and that's just fine.

To me, this amp really captures the traditional "tube sound" in a positive way. It's got excellent detail, a very black background, and somehow manages to tame treble harshness while remaining highly articulate - the balance in the treble region is very well done. The weak spot seems to be low-end performance, where it is good but not great.

Niimbus is comparatively more dynamic, with an even blacker background (though again, the Stratus is already excellent). The solid-state amp comes across as more linear, more even handed, but also more punchy and bombastic. And that bass? Control, texture, extension, all go to the Niimbus by a large margin. Treble on the Niimbus is a touch more prominent, doing less favors when playing poorly done material but exhibiting more clarity when playing quality tracks. I also note the solid-state amp successfully drives a wider range of headphones, from sensitive IEMs to difficult planars and everything in between. Stratus does well enough but isn't the greatest at these sensitivity extremes.

Still, there's something magical about the sound of the Stratus. I could absolutely see headphone nuts owning both amps, alternating between the head (Niimbus) and the heart (Stratus) as the mood strikes. I have yet to hear the newer/more expensive Stellaris, but if it's anything like the Stratus, I'm already sold on the sound (if not the price).

*The TTVJ 307A ($6,000) is a somewhat rare amp designed by the legendary Pete Millett. It launched about 10 years ago in limited quantities, and is the precursor to the (slightly) more well-known Apex Pinnacle.

Of all the tube amps in this comparison, the 307A sounds most similar to the Niimbus US4+. Both models are largely neutral, with similar tonal richness and excellent speed. Both have superb micro-detail and a correspondingly well-defined soundstage. The main difference seems to be at frequency extremes, where the 307A manages a silkier treble and the Niimbus has more low-end solidity. At first glance, this makes the Niimbus feel darker/more bass oriented, and the 307A feel lighter/brighter. But this is an illusion of sorts, and more focused listening reveals the amps to be much more similar than different.

The 307A is a potent amp that actually does quite well with difficult loads. Yet Niimbus is even more versatile. Something like an HE-6 or Susvara played at really high volume has the 307A losing just a bit of composure, while the Niimbus feels effortless. And with more sensitive headphones like the Utopia or K812, the 307A comes on a bit strong at low levels - you really don't get much usable travel on that volume knob. Niimbus, with its adjustable pre-gain and 256-step attenuator, offers much more range and thus a more enjoyable experience.

There doesn't seem to be many 307A amps in the wild. So this comparison perhaps isn't very useful. But for those who have had the pleasure of hearing this fine amp, be aware that the Niimbus US4+ has quite a few similarities. It's not an exact match, but comes surprisingly close considering the variance in topologies.

*Eddie Current's Balancing Act ($3,950) is one of my favorite amps ever. The version used for this comparison used some extremely costly tubes though again, I didn't write down the specifics. I believe this one had the Electra-Print transformers but I could be wrong on that (I had not realized how many variations of this amp existed, or I would have paid more attention). The resulting sound was stunning - liquidity, air, finesse, and just a totally organic experience that made me want to forget all about the evaluation.
Hours later, when I snapped out of my daze, I was able to spot some things that I liked, and a few which I didn't, in relation to the Niimbus. On the positive side, the Balancing Act has a more credible sense of air on the top end. It outperforms the Niimbus and even the 307A in this regard. Cymbals are spectacular on both of those devices but the Balancing Act is about as close to perfection as I've heard. The other thing Eddie Current's machine gets right more than perhaps any other amp is the sense of flow. It's a transient response thing, where sound is simultaneously quick and yet relaxed... notes explode forth with great intensity and speed, but also convey a sense of ease which is difficult to explain. The resulting sound is very fluid and articulate whilst avoiding any sense of artificiality or fatigue. That probably explains why I didn't want to stop listening.

On the flip side, the Niimbus US4+ has several areas where it outperforms the Balancing Act. For one, Niimbus has an absolutely jet black background. I had no complaints about the BA until I listened back to back and heard how inky the Niimbus is in comparison. If the Balancing Act is a really nice older Plasma display (think Pioneer Kuro or Panasonic ZT60), then the Niimbus is an OLED.... the one has excellent blacks and initially seems tough to beat, but then you realize other is very clearly superior. This, combined with the explosive dynamics and clearly articulated bass textures make the Niimbus feel more "full-range" for lack of a better word.

I also note the Niimbus is more comfortable driving a wide variety of headphones. When the Balancing Act finds a good dance partner - HD800 and Utopia being my favorites, with Elex and K812 not far behind - it sounds magical. But when tasked with a difficult load such as Abyss or Susvara, it simply runs out of steam. Even moderately difficult planars such as LCD-2 and HE1000 can sound a bit uninvolving out of the BA, particularly when playing quiet jazz or classical recordings. Meanwhile Niimbus drives all of these (and more) to their fullest potential without breaking a sweat.

It looks like the Balancing Act is now discontinued. So again, perhaps not a terribly relevant comparison. Nonetheless, I consider this a benchmark amplifier if ever there was one, and I know multiple folks who continue to use it as a reference. Judging by this particular example, I wouldn't say the Niimbus totally blows it away by any means, but the solid-state options ends up being my preference more often than not, and with all but a few headphones.


Conclusions
So there you have it - countless hours spent listening, not to mention swapping configurations. Dozens of headphones, a collection of DACs worth more than my car (which isn't really saying much), and at least a dozen top-class headphone amplifiers. After all that, does the Niimbus Audio US4+ smoke them all?

Hardly. That sort of overly-simplistic comparison doesn't reflect the complex realities of comparing excellent gear. Most of the amps in this roundup have strong points where they lead the pack. None of them does everything the best. Which means choosing comes down to preferences and priorities.

The high points of the Niimbus amp are plentiful: strikingly silent background, robust power output, and a wonderfully balanced signature with excellent detail retrieval and superb tonal accuracy. Then there's the finesse of that unique volume control solution which just works like a dream - perfect level matching at all volumes, plenty of steps for fine tuning, and quiet operation (unlike its predecessor). It's a joy to operate, and frankly makes most other amps feel underwhelming.

If I'm wearing my metaphorical audio reviewer hat, the Niimbus is probably my number one pick overall. It has the greatest "headphone bandwidth", meaning it works exceedingly well with every single headphone I throw at it. Other amps may have greater synergy with a specific headphone or two, but as a whole, the Niimbus is the most versatile amp here (with the possible exception of the Simaudio, which is similarly versatile but just doesn't sound very good to me). In addition, the Niimbus has among the best clarity and insight of this entire group. It allows me to hear the character of each source to a degree no other amp can quite match, though a few come close. When evaluating a new DAC or player, the US4+ would definitely be my tool of choice.

Areas where the amp doesn't shine as brightly include the somewhat polarizing appearance (which, again, isn't quite finalized, but I doubt will stray too far from the prototype), the high price, and a relative lack of emotion - chiefly compared to some of the tube-based competitors.

That means if I switch gears to "hobbyist/music lover" mode, a good case could be made for choosing any number of worthy contenders over the Niimbus.

In tube land, the Balancing Act might tempt me away with its stunning treble, organic flow, and retro good looks. It's been discontinued but used examples aren't too hard to come by. The 307A is more of a rare beast but might be worth tracking down - it's similar to the Niimbus in many ways, but has a slightly more ethereal presentation which is, at times, preferable. I might (strong emphasis on that word) actually like the 307A better than the newer, more expensive Apex Pinnacle that superseded it. Lastly, the DNA Stratus offers a pleasingly stereotypical "tube sound" that I could easily fall in love with - at a significantly lower price than Niimbus.

Speaking of lower prices - in the solid-state world, the Pass labs HPA-1 is a tough competitor, and hobbyists certainly must take value into consideration. True, the Pass lacks some features like balanced mode, and doesn't do as well with really difficult planars. But aside from that it is nearly the equal of the US4+ in many ways, for substantially less money. It also gets bonus points for being far more available when it comes to listening before you buy, as Pass Labs probably has better distribution than anything else here in terms of brick and mortar shops. Beyond that, the Violectric V281 remains a very relevant option. Yes, the Niimbus is better in several key areas, but the price differential may be larger than the performance delta. Unless the user owns an absolutely top-notch source (or plans to acquire one in the near future), I would hesitate to write off the V281.


Does anyone really need to spend $3,000-$6,000 on a headphone amp? Probably not. Spending hundreds rather than thousands is clearly the more reasonable approach, and can still get you a very solid result - see various Violectric/Lake People models, as well as the Arcam rHead, Rupert Neve RNHP, etc. But for those chasing the "ultimate" experience, Niimbus Audio offers a worthy contender with a unique skill set. After extensive listening, I put it in the running for best amp out of the dozen models at my disposal, and certainly the most useful as a reviewing tool. I realize the price is very high, and obviously don't recommend it for everyone... but for certain people it is a compelling option worthy of consideration.

What do you use for a transport? Could you do better without spending a fortune? I bring this up because I'm continually surprised at how little attention some people give to this aspect. I've met quite a few enthusiasts who go all-out on exceptional amplification, quality D/A conversion, precise speaker placement and/or top-class headphones (often with custom cables), signal reclockers, linear power supplies, and so on. And yet when I ask about their transport, the answer seems out of place; it's often just a standard PC or MacBook, or occasionally a decent CD player. I suppose they figure the DAC does all the heavy lifting, so why bother?

In my experience, that is unfortunately not the case. Transport quality does in fact play a potentially significant role in overall system performance. Certain DACs can be more picky than others, but in most cases a quality transport is worth shooting for - especially when everything else in the chain is up to a certain level.

That said, I have also seen people go waaaaaay too far in the pursuit of a quality signal. If you spend more money on your transport than your headphones or your DAC... you're probably doing it wrong.

This leads me to one option for doing it right: the new iDAP-6 from Cayin.



I already started a thread about this device a few months ago, so I won't repeat the same material here. This is more for documenting my experiences with the device after fairly heavy use. Please read through that initial post for information, then come back here to finish it up. I've identified a few weaknesses and a whole lot of benefits - so let's get right to it. I apologize in advance for the somewhat scattershot approach here... this is sort of a stream of consciousness review, or at least much more so than my usual write ups. Hopefully you can still follow along.


SOUND
Cutting to the chase, I'll say the iDAP-6 is killer for localized playback. By that I mean attached hard drives, USB sticks, and SD cards. I use it as a bedside rig with matching Cayin DAC and amp, and don't need any sort of networking whatsoever. Just plug in a card or drive, and go. The interface is logical, the controls simple, and the results sonically impeccable. It's a big improvement over the laptop I used to have in this system, both in terms of sound quality and user experience.

If you've only ever used a standard PC or Mac as transport, you might be surprised at how much performance you've been missing out on. This will vary from DAC to DAC, but in most cases a quality DAC will benefit from a better transport - sometimes by a little, sometimes by a very large amount. Assuming you've got decent amplification and a nice set of headphones/speakers, you'll most likely hear superior articulation, more abundant microdetail, more explosive dynamics, and a greater sense of ease in the treble region. In some cases it really can feel like a DAC upgrade.


(pardon the blur, the text was scrolling and I used a slow shutter speed)

Some DACs have their own processing which helps minimize the importance of transport quality. If that's the case with your device, you might not notice much difference... though some models have options to reduce or eliminate that processing. This applies to the Wyred 4 Sound DACs which have multiple settings for jitter reduction. While using the iDAP-6, I found the lowest possible setting to sound the most pure. Same with the Yulong DA9, which has a simple "on/off" selection instead of a sliding scale like the Wyred devices. In contrast, when using my MacBook as transport, I prefer the DA9 switched to "on" for jitter elimination, and with the Wyred DACs I prefer it turned up almost all the way. If I eliminate jitter reduction and try using the MacBook, the result is rather unwelcome... fuzzy dynamics and harsh, metallic treble.

I've got a few gatekeepers for transport quality these days. First off, I compare the MacBook over USB, which represents a relatively standard consumer-oriented setup. The dedicated transport being tested should be able to ace this comparison, or else I won't proceed further. Next up is an Oppo BDP-105 via coaxial output, which is a step up if not a drastic one. I hear very minor improvements when making that switch. It's not an obvious thing right off the bat, but I do find long-term listening becomes less fatiguing. If a transport can do better than the Oppo, I consider it worthwhile. Lastly, I break out my Simaudio Orbiter, which was a really high-end ($7,200) universal player released about a decade ago. It sports AES/EBU, BNC, coaxial, and optical outputs, all of which are equally superb. The Orbiter is excellent, and I hear a pretty noticeable improvement when I put it in place. Little details like soundstage height start coming in to focus, while dynamic swing is much larger and treble significantly cleaner. If a transport comes anywhere near this thing, it's a definite winner.

The Cayin iDAP-6 matches my Simaudio spinner in performance. This is an impressive feat. For reference, I've compared the Orbiter to more expensive players from Esoteric, EMM Labs, and Accuphase (among others). While those tended to sound better via their analog outputs, the Simaudio was the best of the bunch on transport duty. By extension, that means the little $799 Cayin iDAP-6 keeps up with those megabuck monsters when feeding a separate DAC. Surprising? Not really... by dedicating the device to transport duties, and leveraging the strengths of file-based playback, the iDAP-6 ends up being more focused than those behemoth players. Factor in Cayin's general lean towards high-value, and the build quality being high but not absurd, and it starts to make sense.


OPTIONS
There are some options of the iDAP-6 which I just don't use. For example, Bluetooth streaming. It's aptX equipped (for outgoing streams) and can stream to or from other devices. That's just not something I'll ever use on a device like this. I do use Bluetooth to interface with a remote app on my phone though (more on that shortly). iDAP-6 plays Airplay for Apple devices, which I won't ever bother with. There's also WiFi and an Ethernet connection which allows streaming - but it's not perfect at this point. While it does play music off my NAS, there's an issue where it requires me to log in every session.... it won't save my login information like most other devices will. Until Cayin fixes that, it's not something I care to use. But again, I think the strength here is local file playback, so I probably wouldn't use the NAS much anyway.

Controls are very intuitive using the spinning, pressable knob plus a back button. Anyone can figure this out in minutes. However, using the HiByLink app on my phone is really nice too. It offers a clean interface with expanded options like search which wouldn't be tenable using just the front panel knob. I almost think it's a requirement when dealing with massive libraries. If I just plug in a 256GB USB stick filled with reference tracks, I'll usually stick with the knob.

One complaint, albeit minor: I did run into a few situations where the SD card or USB stick I was using ended up being too slow for playing hi-res PCM or DSD material. It worked, but would occasionally have tiny dropouts within the first few seconds of playback. I speculate this to be when the player tries reading ahead for buffering, as well as loading the image file for album art. Slower cards or USB drives just don't have the speed, so the audio drops out momentarily, and then works flawlessly for the remainder of the track. Still, this is definitely something I couldn't live with, so I make sure to use fast Samsung storage which avoids the issue altogether. Portable SSD storage is great, and even spinning platter portable hard drives are fine - or at least the few I've tried did the job without issue.


OUTPUTS
Without question, my favorite output is the I2S over HDMI option. Obviously you'll need a compatible DAC - I used a PS Audio Stellar Gain Cell DAC as well as a Wyred 4 Sound 10th Anniversary DAC, and both sounded their best via I2S. Based on past experience, the PS Audio DirectStream and NuWave DSD will offer similar benefits. I2S isn't always the best input on every DAC, and can get frustrating due to lack of standardization. But I'd say Cayin made a good choice sticking with the PS Audio/Wyred 4 Sound format.

Other outputs sound great as well. My second choice is usually the AES/EBU which tends to sound the best on a lot of DACs. BNC and coaxial are both present, as is optical, all of which sound quite good too. And don't forget USB - the iDAP-6 can also work with most DACs via USB, as long as the DAC is comfortable with Linux. Honestly the difference between all of these is fairly small, so pick whichever one your particular DAC likes the most. Worth noting: the USB, AES, coaxial, and BNC outputs can handle up to 24/384 PCM and DSD128 (DoP), while Toslink is limited to 24/192. I2S goes all the way to DSD256.




CONCLUSION
To wrap this up, let's talk about the full Cayin stack. My bedside rig consists of the iDAP-6, the matching iDAC-6 tube DAC and iHA-6 solid state amp, plus the HA-1A MK2 tube amplifier. This makes for a stunning combination, both visually and sonically. The iDAC doesn't have I2S (Cayin intends to do another DAC one of these days which does have I2S) so I just go with USB for simplicity. I go balanced out from the DAC to the solid state amp, and single-ended out to the tube amp. Headphones getting the most use lately are the HD650, the Focal Elex, and the Sony Z1R.


This system approaches end-game levels. Running an HD650 from the HA-1A MK2 (with full compliment of Amperex Bugle Boy tubes) makes for a supremely musical, somewhat lush presentation, with unbelievably flowing vocals. I switch to solid-state amplification for the Focal Elex, which has resolution for days using a Moon Audio Silver Dragon balanced cable. This makes for a supremely "open" presentation, with stunning imaging and soundstage accuracy. I'm still trying to come to grips with the Sony.... it's nowhere near as technically accurate as the other two models, but nonetheless offers its own unique take on the music. Which I sometimes prefer. It reminds me of speakers from Zu Audio or Audio Note - measurements are not great at all, but somehow the sound can be really inviting with the right music. Interestingly, I like the Sony out of both amps, depending on my mood. I can't decide which is actually the better match. Prior to this trio I spent a lot of time with the HD800S, Ether C, HE1000, THX00, and a modified/fully balanced AKG K812, all of which sounded top-notch with the Cayin gear. Aside from having too much gain for IEMs, there's not much this system can't do.

I really feel that the iDAP-6 is an integral part of getting this system performing at such a high level. It's obviously a perfect aesthetic match, but more importantly it just sounds flat out better than most other transports out there. I can't think of anything that touches it for the price. The closest competitor would probably be a streaming solution from SOtM or Sonore, plus a matching linear power supply. Those will end up costing more than the iDAP-6 and won't sound any better. Plus it's just a different experience - I think of those as being primarily centered around Roon. Now, I'm a huge Roon fan, and I use the SOtM sMS-200 with great results, but the iDAP-6 is something else entirely. Local playback has its charms, offering a simplistic experience more akin to grabbing a CD and pressing play. If Cayin can eventually iron out the NAS connectivity issue, that would give it a broader appeal, but for my needs it's just about perfect as-is. If you're looking for a transport upgrade, with or without the matching Cayin DAC and amp: the iDAP-6 is an incredibly strong contender.

Full review can be seen HERE

In summary, this an amazing upgrade for many devices that benefit from cleaner power. It can be configured a number of ways, including dual outputs at different voltages.

Full review available HERE

Quick summary to satisfy the minimum character requirement: The Matrix X-SPDIF 2 is a fearsome competitor to the popular Singxer SU-1. Matrix matches the Singxer when run straight from USB, and can surpass it when using an external linear power supply.

Review available HERE - I will just say a few words here to fill the minimum character requirement. The Euphony PTS silent server is an extremely high quality music server. It's not priced like a high-end server, as those often start around three times as much and rapidly increase from there.

A few months back, I had an interesting discussion with a forum friend. While chatting about the general state of all things audio, he congratulated me for my recent debut at Digital Audio Review, and mentioned how often he agrees with my gear assessments. According to him, most people find me "fair and balanced" (with no political reference intended). How nice! I was actually feeling pretty full of myself. Then he added "Shame about Yulong though..." as if to point out that my record isn't completely sterling.

"What do you mean?" I inquired, genuinely having no clue where he was going with this. He became hesitant, so I urged him to be completely honest - I'm a tough dude, I can take it. So he dropped a bit of info on me that I really hadn't heard before.

His opinion, which he claims is shared by many others he knows, is that Yulong gear doesn't sound all that great. My reviews helped popularize their DACs and, to a lesser extent, their headphone amps, but none of it is actually very good at all. It's a black mark on my otherwise pretty credible history of assessing gear.

Now, I happen to know plenty of other folks both online and in person who use/enjoy the Yulong gear. So I know this isn't a universal opinion. But still, the person mentioning this to me is a very reliable. I just didn't know what to make of it.

Fast forward a few weeks. By sheer luck, someone else reached out to me, asking about Yulong's DA8 DAC. They had recently purchased a used model (original, not Mark II) on the forums, and found it sounded totally different than my review. They honestly thought it might be broken. I offered to have a listen and see what I thought. Within a few days I had their DA8 up and running, and was pretty shocked by what I heard. This was indeed a mediocre sounding device... weird, congested low-end performance, tizzy highs, and funky imaging. This was totally different from the sound I experienced and ultimately wrote about in my review. I got the other friend involved and he confirmed this as matching his experience with the DA8 he had owned prior. Based on that, I'm ruling out the possibility of this particular DAC being broken, though I guess it's still possible on some level.

This really surprised me. I've covered multiple Yulong DACs over the years and generally noted some consistency from unit to unit. Not that they sounded identical, but there was definitely a similarity - I'd call it an evolution in sound, starting with the original D100 and ending with the DA8 mkII. There were a few diversions along the way, such as the rich, creamy D18, but when viewed as a whole I think the sonic trajectory is pretty clear. Unless we count this particular poor-sounding DA8 which doesn't fit in there at all.


Now, there's been a lot of hand-wringing lately about sample to sample variation among flagship headphones - Focal's Utopia being the main culprit, and of course Audeze which has struggled with consistency for years. We don't often talk about variability in source components but it's something I've experienced on occasion - the most prominent example being the Mytek Stereo192-DSD. At one point I had two of those here and they sounded drastically different... if one of them wasn't broken, the other must have had a substantial revision at some point, because they were very obviously not the same. This is something I've confirmed with others as well, so I don't think I'm crazy (or at least not based on this).

Could the same thing be at play with Yulong gear? I don't know, but it would go a long way towards explaining the differing opinions on the brand. Sure, every audio maker faces this to some extent, but now that I look closer I find Yulong has some pretty vocal detractors as well as plenty of satisfied users. It's almost as if the two groups are hearing completely different things.... well, perhaps they are. I can't speak as to what causes this, or how often it happens. Perhaps counterfeit parts inadvertently made their way into a few batches? That sort of thing is surprisingly hard to combat, even when the manufacturer is diligent. Your guess is as good as mine. All I can say definitively is my positive experience with Yulong has been consistent across a wide range of devices. Make of that what you will.


Anyway, my whole motivation in writing this is to discuss Yulong's latest project, the DA9. This is a pretty major departure from the DA8 and DA8 mkII - aesthetically, but also in terms of design and, ultimately, sonic presentation. Pricing remains the same at $1299. Remember how I said the prior Yulong gear tended to have a "house sound"? The DA9 goes is a fairly different direction, to the point where lovers of the prior models may not care for it, and those who disliked the earlier stuff could very well love it. Think of it as a sort of "fresh start" for the company, in a good way.

Design
Yulong went in a new direction with the DA9 on multiple levels. Externally, the device now looks a bit like the M2Tech products such as the Young DSD DAC. This is a good thing as those were always sharp looking devices even if the sound didn't quite keep up. The DA9 enclosure comes in black or silver but the front panel is always gold. It's a handsome faceplate that makes me wish I had my old Sonic Frontiers transport in gold to go along with it.



The information display is back to a smaller text-based LCD from the D100 and D200 rather than OLED from the DA8 series. I guess some people had issues with the OLED in terms of longevity (I never had a problem). Gone are the multitude of buttons for settings and selections - this time around everything is accomplished by spinning or pressing/holding the multi-function knob. Press and release immediately to cycle inputs. Press and hold briefly to switch between headphone mode, DAC mode with volume control, or pure DAC mode with full scale output. Press and hold for about 4 seconds to unlock filter selections, and hold roughly 8 seconds for sound adjustment mode (which I'll discuss later). It's a bit cumbersome when accessing filter and sound adjustments, but thankfully that sort of thing tends to be set and forget. The final noteworthy trait of the front panel - a balanced headphone output. We've seen these on Yulong's dedicated headphone amps but this is the first combo DAC/amp unit to get balanced drive. As we'll discuss shortly, that's a good thing.


The rear panel brings us back to classic Yulong, with the same connectivity we've seen since the original D100 which launched 7 years ago (a lifetime in DAC years). That means USB, Toslink, coaxial, and AES inputs, and then RCA and XLR outputs. Something a bit different this time around - all inputs support PCM up to 24-bit/384kHz, though source devices which manage such high sample rates are rather uncommon. Not only that, but all inputs can do DSD64 and DSD128 via DoP. I confirmed DSD64 using coaxial and AES, but I didn't have a way of testing Toslink, nor DSD128. This could be useful as the market for external USB to SPDIF "bridge" devices heats up. The popular Singxer SU-1, for example, can spit out DSD64 via SPDIF, and the Audiophilleo "Special Edition" version goes up to DSD128, as well as PCM at 384kHz. Many DACs won't accept those, but the DA9 does.


Speaking of DSD, the DA9's USB input does DSD64 and DSD128 via DoP, as well as native mode up to DSD256. This is useful for those folks using Roon or HQplayer to offload filtering/upsampling. Having both methods available increases compatibility for the widest amount of supporting equipment, which is always a good thing.


Internally, the design is pretty much all-new - but skip ahead to the listening section if you don't care about excruciating technical detail. Starting with the large Plitron toroidal transformer, the linear power supply has a decent amount of filtering capacitance and a total of 18 groups of low noise regulation spread throughout the PCB. USB input is an XMOS U8 which runs off the device's linear power supply - no dirty USB power to worry about. All digital inputs pass through a Bravo SA8804 which is a custom DSP used for clocking, wave shaping, and jitter reduction. Yulong (the designer) tells me the SA8804 uses a "phase-locked loop with synchronous low jitter clock-gen" which achieves even better jitter performance than so-called "femtosecond" clocks. The signal is then delivered to AKM's latest flagship chip, the AK4497, fed by a dedicated ADM7150 ultra-low noise regulator.






The AK4497 DAC spits out a balanced signal which passes through the low-pass filter stage comprised of OPA1611 and OPA1612 opamps, then off to an output buffer made from OPA1622. Signals then go out the XLR outputs or get converted to single-ended for RCA connections.


In keeping with the theme of "change", volume control is handled a bit differently this time around. Where prior models used the integrated 32-bit Sabre volume control scheme, the DA9 instead uses a PGA2311 digital controller to regulate levels in the analog domain. This means, in theory at least, a quality lossless implementation, good for full resolution even at very low volume settings.



The integrated headphone amplifier is described as a fully balanced, fully discrete, DC coupled class-A design with JFET input and high-current output. Balanced mode is potent, rated at a full 3W into 32 ohm loads. 300 ohm headphones see 460mW while 600 ohm cans get 230mW. Single-ended mode sees a reduction but it's still plenty powerful - 2W into 32 ohms, 230mW into 300 ohms, and 110mW at 600 ohms. Output impedance is a 2.2 ohms in balanced mode and about half that in SE, which is low enough to avoid problems the vast majority of headphones and IEMs.

Before I go any further with the sound portion, I have to mention the tweakability of the DA9, which is unique if not entirely successful. There's a choice of filters - Sharp Rolloff, Slow Rolloff, and Super-Slow Rolloff. I tend to prefer the Super-Slow option for general listening but the differences - as usual with selectable filters - are subtle at first. Spend some time with them and I believe they do make a worthwhile sonic contribution, but don't expect a whole new DAC with each filter selection.



The DA9 also has a unique "sound mode" adjustment option with three different choices. Sound Mode 1 is flat, Sound Mode 2 is U shaped, and Sound Mode 3 is n shaped (as in an upside down U). Yulong says mode 2 is "delicate and firm" and might be useful with classical music. Mode 3 is "laid back with stronger voice presence" which might work best with jazz and vocal oriented music. Each mode is essentially a very gentle EQ slope. We're talking differences of perhaps 1.5dB over the entire frequency spectrum - which just isn't very noticeable most of the time. To put that in perspective: the variation in room acoustics from one room to the next will be far more significant. It's an interesting idea but I feel like it should have been more dramatic... or else why bother? As it stands, I just leave it on Sound Mode 1 and call it a day. Keep in mind these adjustments only apply to the line-out, not the headphone section.




Listening
Yulong recommends letting the DA9 warm up sufficiently prior to critical listening. As is my standard practice, I left it on for my entire evaluation. I can't say for sure it makes much difference, but I don't want to take any chances.

I started things out with a really simple setup: Roon playback via Surface Pro 3, using Yulong's CU-2 USB cable. I listened through the Sennheiser HD800 using the stock cable and then an Effect Audio balanced cable. The Surface and the DA9 were both connected to a simple CablePro Revelation power strip, with the Yulong CP-1 cable delivering power to the DAC. I figured this simple, direct chain would make it easy to bring out the character of the DA9, and I was right.



The resulting sound is, as I've mentioned, quite different from what I've experienced on prior Yulong models. Where the DA8 was somewhat warm and a little dark, and the DA8 mkII built on that for a more balanced (but still slightly warm) signature, the DA9 is totally different. It's generally neutral as far as not being overly warm, or obnoxiously bright, or any other major coloration. If pressed, I'd say there's a bit of a "lighter-weight" tonality going on, as exemplified by devices from Benchmark and Mytek to name just a few. In that sense I suppose it shares a passing resemblance to the older Yulong D200. But there's a distinct "sweetness" to the sound which makes it unique.

Sweetness is hard to describe but I imagine many readers know what I mean, at least to some degree. There's a certain delicacy, a sort of softness to the sound, though not in a bad way. Where the DA8 might have been called thick and a perhaps bit slow with regards to transient attack - at least compared to some competing DACs like the Matrix X-Sabre - this new model is explosively quick, yet not sharp in the least. The focus is much more on the decay, which can linger for what seems like ages when the music calls for it. It's an interesting mixture of agility and resolution, all packaged in a way that sounds extremely "un-digital" (yes, I just made up a word).

I know I called the original DA8 very analog sounding, and I still contend that is the case... at least for the particular example I reviewed. If my above description of the DA9 made you think "analog" as well, I don't blame you. But it's a totally different approach to get there. Where the DA8 would soften poor recordings by toning down the top end, the DA9 is more extended and sparkly up top - but still easy to listen to. It achieves this by its gentle attack and near complete lack of digital glare. Perhaps the word "graceful" is a term that applies - softness seems to imply something is missing, and that's not really the case.



The resulting sound is probably the best I've heard from Yulong. DA9 gives the strings of Zoe Keating a beautiful reverberation that the prior models can't match. It brings out the delicacy of Prescilla Ahn's voice on her older albums, versus the more confident tone she adopts on new material. And it's spectacular with percussion, helping reveal nuances like the precision of Jack DeJohnette, the swing of Max Roach, and the explosive power of Elvin Jones. Overall it's a thoroughly satisfying result - one that works particularly well with headphones such as HD800 or the Dharma which can sound overly sharp in the wrong system.

If I switch to the other filters, things get a little more "typical". There's still a gentleness to the presentation, but Slow Rolloff mode has less of it, and Sharp even less still. Sharp in particular has a more direct, exciting approach, where transient attack is more explosive. I can hear the appeal of these modes, as they add a sense of immediacy that works better in some systems. Sharp mode has the most expansive soundstage if that really matters to you, though the other options trail very closely behind. For me, the Super Slow option is still the clear winner.

AKM likes to use the term "velvet sound" when discussing their latest generation of DAC chips. I'm not sure where they mean to go with that, as the rest of their marketing material is hard to parse due to translation issues. But if we stick with the "velvet" term I'd say it captures the DA9 essence fairly well, at least when used with the Super Slow filter.

I've heard other devices using AKM chips such as the AK4490 which shows up a lot. None of them sounded like the DA9. I've also heard the Gustard A20H which packs a pair of AK4497 in dual mono - and I didn't care for it much. There was definitely a disconnect between its technical ability and the soul of the music.... it sounded unnatural to me. The Yulong, despite having a single chip, does a far better job of living up to the "velvet sound" concept. The Gustard DAC is perhaps more explosive and dynamic but none of that matters if the timbre of instruments is off. As with Yulong, I've heard vastly differing reports about Gustard gear, and I don't know what to make of it - all I can do is report what I hear.

Downsides? No DAC is perfect, and the DA9 is no exception. Soundstage is expansive but imaging is a bit less precise than the DA8 mkII, particularly when used with Super Slow mode (which, again, I feel is a fair trade-off, but you may disagree). And if you're looking for a bass monster, you won't find that here. Low end reproduction is clean, clear, and plenty satisfying, but you can probably do better at this price - the Eastern Electric MiniMax Supreme comes to mind, as well as the previously mentioned Matrix X-Sabre. And if you like a thicker tonality, there are plenty of others in this price range that should do the trick, such as the new Metrum Amethyst NOS DAC. No, the DA9 is not looking to out-power or out-resolve the competition, but rather to win over the listener with it's beautiful tone. If you want to focus purely on resolution or bandwidth, the older DA8 mkII is probably a safer bet for your needs.


Headphone amp and other tidbits
When I swap headphones and try external amps like the Pass Labs HPA-1 or Violectric V281, I get a better sense of what the DA9 integrated amp is capable of. As I've said, you really want to go with balanced mode. SE is workable but seems to be missing some of the magic in comparison. The presentation becomes more two-dimensional, and the sweet tone is less obvious.

If you must use the single-ended out, it's best to stick with low impedance dynamic headphones. Something like a Fostex or Grado or Ultrasone doesn't miss out on nearly as much in SE, as opposed to higher impedance Sennheiser or beyerdynamic models, or most planar magnetics - those really respond to the extra current available in balanced mode.


CIEMs work reasonably well with the DA9. Sensitive models such as Empire Ears will have a bit of background hiss, while others have a nice quite background, and the 99 step lossless volume control comes in handy for dialing them in just right. Yulong's headphone stages haven't always been kind to IEMs but this one is usable in most cases.

Using a flagship stand-alone headphone amp shows that the DA9 is still a better DAC than headphone amp. The key difference is dynamics - while the DA9 is very potent for an integrated headphone amp, it still doesn't match the bombastic response of the Pass or Violectric. The Pass brings out more top-end detail while the V281 improves bass rumble and tonal solidity. None of this is surprising given the prices involved.

For a more real world comparison I switched to the Arcam rHead which is excellent at $599. I find it superior to the SE mode but pretty evenly matched with the Yulong balanced out. If pressed, I'd say the Arcam has an edge in clarity, and highlights that midrange sweetness a tad more, but it's a close match overall. I could find a bunch of more expensive amps that don't measure up to Yulong's integrated amp, as well as a few more affordable stand-alone options that do a better job... but that would make this already long review even longer. Suffice to say - the integrated amp is surprisingly good, if not reference caliber.

For preamp duty, the DA9 is clearly better than the prior Yulong gear. That lossless analog implementation really does the trick. With a 4.2V output and 22 ohm output impedance, this little box can work with pretty much anything, and the 99 step volume control should be plenty. I briefly threw it into my speaker rig paired with a PS Audio S300 amplifier and driving Usher Dancer Mini One DMD speakers, and the result was very pleasing. Excellent drive and tonal richness, which is usually the first thing to go on a DAC-direct setup. These results apply even at really low volumes which I very much appreciate. My only complaint is the lack of remote - you can't win them all I suppose.

Lastly, I'll mention sources. The Yulong is surprisingly competent when using basic transports like an old Blu-Ray player or a standard laptop. The proprietary DSP reclocker works its magic and the result is more than acceptable. For a lot of people, there's no need to worry about using anything beyond a pedestrian source, as even the most basic pairing will do a pretty good job.


For the rest of us audio nuts, the DA9 still rewards quality sources, though it still remains less critical than other DACs. I used an absurdly complex chain featuring a Zenion server with a dedicated linear power supply, running Roon, streaming to a SOtM sMS-200 with a separate linear PSU, then out to a Wyred 4 Sound Recovery (also with linear PSU), then out via BMC PureUSB active cable to a Singxer SU-1 - then finally out to the DA9 using an AES cable. This chain sounded remarkable but honestly it wasn't worth the massive cost or complexity compared to just running direct from the sMS-200 or even straight from the Zenion server via USB. On the spinning disc side of things, an Oppo 103 via coaxial sounded just about the same as several expensive transports I have on hand from Simaudio and Esoteric. I spotted no discernible difference between AES, USB, coaxial, or even Toslink, which is pretty remarkable in and of itself.

Remember, the DA9 doesn't care so much about USB power quality either, as it uses it's own internal PSU for that. So filtering the signal with a BMC PureUSB or Wyred Recovery results in smaller than usual gains - DA9 already reclocks incoming signals with very impressive results. Overall I'd say the jump from basic (Surface Pro 3 for example) to some type of modestly higher quality source (sMS-200, microRendu, decent CD player, etc) seems to be worthwhile. But from there I wouldn't bother going extreme.




Final Thoughts
I still don't know what to make of my experience with the Yulong DA8. The poor sounding version was quite disappointing, while the better example was easy to recommend. I'm going to chalk it up to a bad batch and move on because that's really the only thing that makes sense to me. I never heard about the DA8 mkII sounding inferior, so perhaps whatever bug existed was ironed out by then - not a satisfying conclusion, but there's really nothing else to be done at this point.

In any case, Yulong's DA9 is worth a listen if you get the chance. If you've heard prior Yulong models and didn't care from them - this thing is something different. You might like it. On the flip side, if you've been a loyal Yulong user - this is something different, and you might not like it. Especially using the Super Slow Rolloff filter. But I figure it's worth a try if the opportunity comes your way.

Overall I'd put the DA9 on par with the popular Mytek Brooklyn. While Brooklyn offers more bells and whistles, its more affordable competitor from China is very similar as a DAC - assuming the Sharp filter is in play. Using Super Slow makes the DA9 preferable to my ears. The DA9 is clearly superior in terms of headphone amplification, regardless of filter choice, as long as the user has access to balanced cables. No doubt Brooklyn will command the lion's share of attention, both on the forums and in the audio press, but those willing to go with a lesser known device will find themselves rewarded.

Veritas.

Latin for Truth.

In a perfect world, this describes the ideal source component for quality audio reproduction. Convert those ones and zeros faithfully, making an honest representation of the original source material, and send that resulting analog signal out to a gain stage. Simple, right? And yet here, in the real world, it doesn't seem to be quite so easy. Take a look at the many hundreds of current designs, using different and often contradictory approaches to achieve the same goal. That number balloons much higher if we include out-of-production models. And that's not to mention the designs which aren't even looking for truth - instead actively seeking to put their own coloration on the sound. The options can be overwhelming.

My personal weapon of choice for musical truth since 2011 has been the Invicta DAC from Resonessence Labs. I've tried many dozens of competitors during that time frame, and none seem to have the same sense of clarity, spaciousness, or tonal accuracy. Some, like the BMC UltraDAC, do an exceptional job in their own way, and I've got a list of favorites covering a wide range of prices. But if I have to choose just one, Invicta remains my favorite.

Resonessence Labs initially launched the Invicta at $3999. Since then, the device has evolved from original to v2 to Mirus to Mirus Pro, bringing significant sonic improvements with each step. These updates, combined with inflation, have pushed the price up to $5999. Not the most expensive DAC in the world by any means, yet still high enough to be out of reach for a large number of enthusiasts. Resonessence Labs needed something more affordable to expand their user base.

This was accomplished with the Concero line ($850) and the diminutive Herus ($350), which put Resonessence quality in the hands of many. I enjoy these affordable models immensely, each in its own way, and find them very competitive in their price class and beyond.

And yet... there's an obvious and rather large gap in the middle there. For years, folks have been hoping for a stripped down Invicta with a lower price tag. The formula seemed obvious - remove the SD card playback function, lose the integrated headphone amplifier, reduce the connectivity options (Invicta has 7 digital inputs, which is more than most people need), and perhaps simplify some internal design aspects, all while preserving as much performance as possible.

I'm happy to say that with the Veritas, Resonessence Labs has done just that.



At $2850, Veritas is less than half the price of its older sibling. It shares quite a bit of the Resonessence design language though - an attractive milled aluminum enclosure with surprising heft, an OLED display, a "clickable" scroll wheel for navigation, Apple remote compatibility, and a generous array of inputs and outputs. Internally, we get several custom Resonessence Labs filters, their proprietary FPGA engine, and custom USB code executed on a Cypress semiconductor chip rather than the usual suspects from XMOS or Amanero. This is stuff you just won't find anywhere else. And not that it matters much by now, but Veritas was the very first product on the market using the new ES9028Pro DAC chip, thanks to the uniquely close relationship between ESS and Resonessence Labs.

The resulting sound is very much in the same spirit as the Invicta. Words like clean, clear, accurate, and neutral all spring to mind, but don't think for a second this is an overly dry, polite DAC. Veritas has bass depth for miles, and a sense of tonal accuracy matched by very few competitors. The resulting sound is one that I'd place on the same performance tier as the Invicta "v2" from a few years back, prior to the Mirus upgrade which doubled up on the number of DACs per channel (from 4 to 8). This is quite an accomplishment from a device with reduced complexity, size, and price.

And that's where I'll stop. Rather than have me go on and on about the performance of the Veritas, I'm going to switch things up and focus on comparisons. I've had a massive amount of DACs come through the house over the last year or so. Many of them are devices which compete directly with Veritas based on price or feature set. Others are helpful just to give a sense of where the Veritas falls on the sonic spectrum, even if their price is significantly higher or lower.



A quick aside about color choices: Veritas is available in silver, black, and the interesting gold color as seen in my review unit. It's hard to accurately capture the proper color as it tends to look different based on lighting. At times it seems more rich and dark, while other times a sort of pale yellowish hue emerges. You'll see that in my pics, though some variance may be due to editing to bring out maximum clarity. In my humble opinion, this thing looks fantastic in gold. I wish I had my old Sonic Frontiers transport with the gold face - that would be a stunning combo. Most people would probably be more inclined to stick with traditional colors but I'm glad Resonessence Labs gives us the option.

The main system used for these comparisons, down to the excruciating details for those who care:

SOURCES: Aurender X100L, Singxer SU-1, Examplar modified Oppo BDP-93, SOtM sMS-200 and Wyred 4 Sound Recovery both powered by Wyred 4 Sound PS-1

AMPS: Pass Labs HPA-1, Violectric V281, Cayin HA-1A mk2 (with Amperex Bugle Boy 12AU7s, Hammond-branded Amperex 6BQ5s, and Tung-Sol 12DT5, all NOS tubes), Arcam rHead (used mainly with IEMs), custom-built high-bias KGSShv (for Stax, obviously)

HEADPHONES: Sennheiser HD650 and HD800, HiFiMAN HE-1000, Enigmacoustics Dharma, Audeze LCD-3, Stax SR-007mkII and SR-4070, Empire Ears Zeus XR ADEL, Noble K10, NG Audio Capricorn, Jomo Audio 6R

ANCILLARIES: Equi=Core 1800 balanced power conditioner, BMC PureUSB active USB interface, Better Cables Blue Truth II and Silver Serpent interconnects/digital cables, Cabledyne Silver Reference AC cables, Zoethecus rack with Z-Slab shelving



There were also times when I used a wide variety of other components - the above is just the stuff I tended to use most.



All comparisons were done with both units on hand for direct back and forth, though I had more time with some of them than others. So there will be certain entries with more info and some with less. This is going to be more stream-of-consciousness than my usual review style - hopefully a clear picture will emerge.


Mytek Stereo192 DSD ($1695)
Released back in 2011, this device is a bit long in the tooth considering the rapid pace at which DACs are moving. While the front panel looks quite modern (only on the silver version though), a Firewire port around back lets us know we're dealing with semi-vintage equipment. Still, it's a very widely used device in my experience, so it makes for a good benchmark (no pun intended).

I'm convinced there must be some major unit to unit variability going on with this device. I've heard several examples over the years and to be completely frank, they sounded terrible. Thin, brittle, shouty, with an odd cardboard-cutout soundstage. I couldn't fathom how anyone could enjoy that type of sound, but.... different systems, different ears, etc.

Fast forward to last year, when a friend brought one over and said "try this out". I wondered what I had done to offend him - then I plugged the thing in and had a listen. To my surprise, this was a perfectly enjoyable DAC. It had respectable detail that was not annoyingly bright, a more fleshed out tone, and a reasonably defined soundstage that did not sound completely artificial. This was a total night and day transformation compared to the last examples I spent time with. I don't know if there was A) a silent refresh to the design at some point, or B) this was just a particularly good example, or C) the others I tried were extremely poor examples. Whatever the case, if this is how at least some of the units sound, I better understand why the device became popular.



While I did enjoy this particular Mytek more than the others, I still didn't find it anywhere near the level of the Veritas. It had a certain sterility to it, a sort of artificiality which never managed to go beyond "a good approximation" of real instruments. Again, it was reasonably enjoyable for the most part, but Veritas was far more convincing. The better the system, the more obvious this improvement became.

In terms of balance, the two weren't drastically different, though Veritas did manage significantly more low end gusto. The Mytek felt like it gracefully ran out of steam in the bottom octaves, almost as if listening through a quality mini-monitor instead of a true full-range speaker. Leading edges initially seemed fast on the Mytek yet on direct comparison seemed overly vague, with Veritas being more dynamic and well defined on guitar picks and percussion strikes. This may sound like audiophile nit-picking but I think most listeners would pick up on it pretty quickly, and enjoy Veritas more.

Ultimately, I'd say Veritas would be a logical upgrade for those who enjoy their Mytek (which I have to assume means a "good" Mytek, otherwise I can't relate at all) but want to upgrade to something better without a fundamental change in character. Veritas is similar enough while doing pretty much everything better.




Mytek Brooklyn ($1995)
This can be considered the successor to the Stereo192 DSD which appears to be discontinued at this point. I've only heard one example of the Brooklyn, and my experience with it was reasonably positive overall. I can't say if all examples sound the same but for now let's assume they do.

Used purely as a DAC, this thing is pretty enjoyable before factoring in price or doing any comparisons. It has a neutral and nimble presentation with a nice improvement in treble clarity over the old model. After spending more time with it, I discovered that while perceived detail was high, it was also slightly exaggerated. This initially made it sound extremely resolving, when it reality it is not quite up to that level. Still, it's far less offensive than the Stereo192 which retained an etched feel even on the "good" example.

Midrange on the Brooklyn is less involving than I'd like, and consequently I found myself connecting with the music less than I do with Veritas. This was not immediately obvious but became clear after extended listening, and even more so during back to back comparisons. Veritas also has a larger sense of scale to orchestral works and other large presentations. While Brooklyn does an acceptable job here, and even beats some more expensive competitors (Bryston for example), Veritas clearly stands out as being more spacious and three dimensional. It's a physically smaller DAC that makes a rather large sound.

Overall, Brooklyn sounds enjoyable enough, and it's a definite step up for Mytek. I think most people would have a reasonably good time with it in most systems. Unfortunately, the value just doesn't seem there. That may sound odd considering it packs a built-in headphone amp and preamp functionality complete with phono stage. Sounds like a very well-rounded package, right? For $850 less than Veritas, you get more bang for your buck.

Or do you? This extra stuff is only worthwhile if the user takes advantage of it. The DAC is pretty nice but the headphone amp is thoroughly mediocre in my opinion. The little Arcam rHead ($599) is FAR better, as is the integrated headphone out on the diminutive Grace Design m9XX ($499). The DAC/amp combos I'm used to in the $1K to $2K range - Anedio D2, NuPrime DAC-10H, BMC PureDAC - are all substantially better than Mytek's offering, which comes across as sterile and boring. To be fair, it's better than the Stereo192 was, but that's not saying much.

I don't do vinyl but I suspect most aficionados would prefer their own phono stage. I can't really comment on that though. I will admit the preamp functionality is very well done. That may actually be the best part about Brooklyn. Veritas does fine going DAC direct but loses tonal richness as volume drops - a problem the Mytek does not seem to have. So Brooklyn may rightfully have some appeal to speaker listeners wanting to ditch their dedicated preamp.

Still, the core functionality here is bringing bits to life, and in that respect Brooklyn is what I'd call good, but not quite great. Which is why I find it overpriced in the end. Yes, Veritas does indeed cost more and offer less functionality, but it really nails the critical DAC aspect, which in my mind is by far the most important part.

As an added wrinkle to this already complex comparison - I had a chance to briefly run the Brooklyn with an external linear PSU, and it seemed to really help. I used a Wyred 4 Sound PS-1 modular PSU with the high-current amp module but unfortunately only had a brief listening session with it. I had already committed to shipping the DAC back to its owner when the PS-1 arrived so the timing just wasn't right. I can't really say how the resulting sound stacks up to Veritas but it did seem more competitive. There was a distinct improvement in tonal richness which really helped flesh out the performance and make it more engaging. The Wyred PSU upgrade goes for $900, which would bring Brooklyn up to almost exactly the same price as Veritas, so that's something to consider.




BMC UltraDAC ($3990)
This is one of my favorite DACs, probably second only to the Invicta. I tend to like it more than the Veritas in certain situations, but not always. The UltraDAC reminds me of my favorite older DACs such as the Classe DAC-1, which I regret selling to this very day. It has a somewhat more "musical" sound, deviating from pure neutrality with just a hint of warmth and a very slightly smooth top end. It's more dynamic and alive while Veritas tends towards matter-of-fact realism, if that makes any sense. I do have to stress that while Veritas is more straight-forward neutral, it does not cross the line into being clinical or cold like the Benchmark and even Vega sometimes can. Unless of course you pair it with overly bright amplification and headphones while playing aggressively mastered recordings. Then all bets are off.



System synergy really comes into play as to which DAC I'll prefer in a given situation. As does musical choice. The BMC excels with classic rock, funk, blues, reggae, and hip hop. Not that Veritas isn't appealing with those genres, but if I'm in the mood for King Crimson, Aesop Rock, Ohio Players, Albert King, or Matumbi, I'd generally prefer having UltraDAC in the chain, depending on the rest of the system of course. If, however, I feel more like playing some Crooked Still (bluegrass), Quo Vadis (technical melodic death metal), Rameses B (drum/bass), Yuna (pop), Starcadian (retro-synth goodness), JJ Heller (girl-with-guitar), or Stravinsky (duh), I would most likely go with Veritas as my preferred presentation. But again, the BMC DAC sounds great with these too.

In terms of value, this is a tough comparison. BMC has a very good integrated headphone output - particularly via the balanced output - which is among the very best I've heard from a DAC/amp combo. It also does a more satisfying job at replacing a separate preamp when listening at low volumes. Running direct to a speaker amp - if I stick with moderate or loud listening, Veritas is quite good. It just doesn't quite keep up with the best competitors at lower levels.

In the end, two questions remain when comparing these DACs - 1) are you shooting for strict accuracy, or would you prefer a small bit of euphonic coloration? And 2) how much is an excellent headphone jack and superior preamplification worth to you?


Benchmark DAC 2 HGC ($1995)
Benchmark now has a newer, slightly more expensive DAC 3, released just a few months back at time of writing. Unfortunately I have not yet experienced that model. Many people are familiar with the DAC 2 though, so it still makes for a relevant comparison. And from what I can tell, the DAC 2 will continue as a current model alongside DAC 3 - at least for a while anyway.

I think Benchmark is interesting. For years, engineer John Siau stood by his original DAC 1 design as being essentially perfect. He didn't feel asynchronous USB was necessary, as his design was effectively "jitter-immune". He felt measurements told the whole story, and that any device which did measure better than the DAC 1 was beyond the reach of human ears anyway. He also seemed to think the DAC 1 headphone output was completely transparent - a sentiment which strained credulity with a good number of headphone users.

That left him in a bit of a pickle when it came time to finally market a new and improved model. As you can see HERE, he eventually got on board and conceded there may be a few small areas of improvement on the DAC 2 which are in fact audible. I haven't had time to look into the DAC 3 much but I notice Benchmark claims its improvements are directly related to using the new ES9028Pro chip. Make of that what you will.

In terms of sound, the DAC 2 is a very big improvement over the old model. This is similar to Mytek's jump from Stereo192 DSD to Brooklyn - a very large, very welcome improvement. But once again, I still find the Veritas to have more compelling sound overall.

While DAC 2 significantly improves the etched, grating upper midrange and glassy highs of the original, some room for improvement remains. Veritas is in another league, with liquid highs that extend indefinitely without causing the same listening fatigue over time. I connect with the music on a deeper level when it sounds utterly natural and unforced, and the DAC 2 doesn't quite manage that on a consistent basis.

I definitely hear a big improvement in harmonic richness over the DAC 1 - there's just more convincing tonal weight to the presentation this time around. But again, it's still not on the same level as Veritas, which sounds like real life to me - I know I keep saying that, and it's probably not in the approved audiophile lexicon, but it captures what I'm experiencing in a way most people should understand. The DAC 2 still sounds thin and clinical by comparison.



The Benchmark has a headphone amp which I'm assuming carries over from the original model. It thus shows improvement due to the DAC section's elevated performance, but as a whole still seems underwhelming. It's a technically proficient sound that lacks soul, much like the amp stages found in the Antelope Audio and Mytek DACs (though admittedly Benchmark is less obnoxious than either of those). I've had people tell me these things are just brutally honest, and I must be looking for some coloration or pleasant distortion. I've enjoyed plenty of extremely neutral amps, from my reference Pass Labs HPA-1 to the integrated headphone out on the Anedio D2. Trust me when I say the amp stages from Mytek, Antelope, and to a slightly lesser extent, Benchmark, are not on that same level.

Back in the day, I'd hear people say they enjoyed their warm, syrupy NOS DAC with tube output stage better than the DAC 1. And while I could identify with that to some degree, I couldn't help thinking that the Benchmark should get points for at least attempting to be the more honest presentation. It wasn't perfect by any means, but many of the popular alternatives were a major overreaction in the other direction. I don't want anyone to think Veritas is anything like that. It sounds to me like Benchmark set out to achieve a certain goal on the DAC 2, and couldn't quite get there. It's the same sound they've been shooting for since the original DAC 1 (which fell significantly shorter) and I do think it's a worthy goal . Veritas pulls it off. It's a series of smallish improvements over the DAC 2 adding up to something very worthwhile in the end, which is why I can handily recommend the Resonessence Labs device over the Benchmark.

I do very much want to experience the DAC 3 though, as I feel the company is on the right path (finally).


Audio GD NFB-7.38 ($1538 plus fairly hefty shipping cost)
I'm not sure what's going on a Audio GD. Back in the day I had a great respect for their sound quality - the Reference 1 and particularly Ref 7.1 were excellent DACs which I found very easy to enjoy. They weren't exactly cheap, but could rightly be called a good value for the money. Those evolved to the Master 7 which increased cost without adding much sonic improvement - at least, not much that stood out during my somewhat limited time with it. Now the Master 7 Singularity version costs even more, and again doesn't really stand out compared to my memory of the older models. Perhaps this is just nostalgia at work, or maybe the improvements mainly addressed the USB input which I didn't really make use of. Whatever the case, I'm not really impressed with the direction I'm seeing from Audio GD.

And then there's the new Singularity 19 which to my ears sounds fundamentally broken. Enough said.

The last model I had a chance to try was the NFB-7.38 - a unit which sports the top of the line ES9038Pro chip along with typical Audio GD beefy design. I don't know if it came out before or after the Singularity 19 as the Audio GD line is constantly in flux. At a price approaching $1700 after shipping, yet with a flagship ESS DAC on board, I was hoping this thing would match the value proposition of the older models. I was wrong.



The 7.38 seems lacking in a way I find hard to describe. While not being thin and brittle like the older Mytek, or lacking involvement like the Benchmark, I nevertheless found it difficult to enjoy this device in my system. It just didn't engage me as the older PCM1704 based models did. Those had a sense of drama and dynamics which couldn't be ignored. This new model seems overly subdued, with a sort of nonchalant presentation that just says "meh". There's a certain softness of note which dulls transient attacks, yet doesn't result in a smooth, relaxing presentation like the original DAC 19 (a warm, musical model which I did enjoy). To my surprise, soundstage remains nicely open and spacious, though a bit lacking in depth, and imaging is fairly precise too. This is not a terrible DAC by any means... it just doesn't engage me as much as I'd like. As I said, it's hard to describe.

It feels wrong to put the little Veritas up against this behemoth. You could stuff four of the Resonessence DACs into the Audio GD enclosure - with room to spare. The Chinese device uses a higher-end Sabre DAC and a much more complex power supply - if we assume a higher parts count equals a more advanced design.

And yet, when I listen back to back, I can't help but find myself far more interested in the Veritas. It's more incisive, transparent and clear, which I sort of expected, but it also digs deeper on the low end, and has a more palpable, rich midband. In short - I can't find any single area in which I prefer the Audio GD, other than perhaps when playing poor recordings that I want to cover up. But I can think of far more effective "sonic band-aid" DACs which don't cost anywhere near as much as the NFB-7.38.

I still think some models in the Audio GD lineup hold promise. I'd love to see the company settle down, stop offering revisions every twelve months, and maybe focus on just a few models instead of the wide range they currently have. But as far as I'm concerned, the NFB-7.38 is not worth the money.


Chord Hugo TT
Hugo is a perfect example of the what is often called "hype" on the forums. For a certain period of time, Hugo was considered by many to be unbeatable, at any price. A true giant-slayer. Folks who disagreed were simply wrong. Then came the much less expensive Mojo and significantly more expensive Hugo TT, which (each in their own unique ways) made people realize the original Hugo perhaps wasn't perfect after all. Now the very expensive DAVE is the current "it" product. You'd better love the oddly named/styled device, lest you lose forum credibility.

Personally, I rather enjoyed Hugo for its expressive sound, but hated the ergonomics of it. I also found plenty of ways to assemble a system where Hugo sounded pretty poor. "Threadbare" was the term I used. Everything had to be just so - great recordings, neutral or warm amplification, and headphones that aren't at all bright - in order to get a result worth listening to. If not, it lacked impact, and I don't just mean low frequency performance.

Chord's Hugo TT ($3995) solves a lot of the issues I had with the original Hugo. The questionable design and build aspects are gone, and in their place is a very well thought out enclosure with appropriate build quality for the price. I seem to recall Chord originally saying the sound would be practically identical to Hugo, but later statements point to improved SQ so I could be misremembering.

Taking the TT as a unique product unto itself, the result is what I'd call "competitive" for the price if not quite revolutionary. The sound is a bit more full bodied than the original Hugo but still lighter and more wispy than I like in some instances. To put things in perspective, Veritas seems less sensitive to system matching than Hugo TT. While both models could be described as neutral or even bright in some situations, Veritas seems more consistently enjoyable across a wide range of associated gear. Hugo TT has potential to sound quite nice but pairs better with more tonally rich amps and headphones. And that built-in headphone output exacerbates the issue. Running HD800 or Enigmacoustics Dharma straight from the jack is a recipe for boredom in my opinion. HD650, Fostex TH-X00, or the Noble K10 all make far better matches, though I still find the BMC UltraDAC far more satisfying as an all-in-one solution.

In the end, Hugo TT is probably worth a look for some people, despite not being my favorite. If you value that colder, somewhat sterile sound, Hugo is better than the Mytek or Benchmark devices, though it costs significantly more as well. Veritas matches and even exceeds the TT's capabilities with respect to microdetail and imaging, while steering clear of being overly analytical, and that makes it the better choice for my preferences.


Exemplar modified Oppo BDP-93 ($2500)
Not many people have heard this device but I wanted to throw it in here anyway just for fun.



This is an Oppo BDP-93 universal player with numerous upgrades by John Tucker at Exemplar Audio. Most of it pertains to power supplies and output stages - very little is done to the actual digital circuitry (which is why I find this comparison so interesting). The sound it produces is slightly thick, warm, a bit on the smooth side, and very dynamic, even if not the most resolving I've ever heard. It's pretty amazing how much SQ they tease out of this device - remember, we're talking about the Oppo 93 rather than the more audio-oriented 95. Despite its humble origins, I'd take this modded 93 hands down over the stock 95 or 105 (I have yet to hear the newly-launched 205). It comes surprisingly close to the tube-modded Oppo "Truth" series from Modwright, which are quite a bit more expensive and complex.

Veritas has a very different presentation compared to the Expo 93. I doubt anyone would ever confuse the two. This could be rightfully be considered a more colored presentation, which is normally something I shy away from. But damn if it doesn't make everything it plays sound pretty spectacular... just a rich, meaty tonality with excellent weighty low-end impact and a flowing, liquid midrange. It's got nice clean upper mids and then a gentle slope to the treble, so it still presents as being reasonably detailed yet also smooth at the same time.

When paired with the right supporting gear - the Violectric V281 makes a perfect dance partner, particularly when driving Audeze LCD-3 or HiFiMAN HE1000 - this thing just grabs me and refuses to let go. In contrast, Veritas is much quicker, more resolving, and plays far deeper into the recording. It matches and often exceeds the Expo bass slam, but you don't really notice due to the more balanced presentation. Piano strikes, cymbals, brush work, and female vocals all show vastly more shimmer and sparkle via the little Resonessence device. Like I said, totally different presentations. To put it in more familiar terms - the Expo 93 reminds me of a Cowon Plenue 1, while Veritas is better represented by the Sony ZX2.

I find this comparison interesting because these two machines approach from completely different angles. The Expo doesn't have the latest in high-end digital. In fact it uses a good-but-nothing-special Cirrus CS4382 8-channel DAC, carried over from the older Oppo BDP-83. For those who recall, Oppo gave the 83 a separate set of 2-channel outputs driven by a CS4398 DAC - the top model in the Cirrus stable. Many sources online attribute a similar setup to the 93 but I've cracked the case open and don't see a CS4398 anywhere. Nor are there dedicated 2-channel outputs separate from the 7.1 analog outs on this machine. Repurposing multi-channel DACs for stereo operation was not all that common until the ESS chips made it simple to accomplish, so I doubt Oppo or Examplar has this running in dual or quad mono (like many Sabre designs these days). No, this is a fairly plain DAC implementation using 2 of the available 8 channels, which is just "good enough". Instead, the device relies heavily on power supply upgrades, shunt regulators, upgraded capacitors, and opamp swaps with class A biasing. Nothing revolutionary by any means, yet the sonic result is very pleasing.

Contrast that with the Veritas which goes smarter rather than more complex in the traditional sense - it almost seems too simple until you remember the custom USB code, that FPGA engine borrowed from Invicta, and those proprietary digital filters. Some audiophiles would scoff at the lack of a huge regulated linear power supply and discrete output stage, but the resulting sound speaks for itself on this little device.

The Expo seems limited by its rather pedestrian DAC section, which I suspect holds it back from achieving true greatness as far as treble, imaging, and soundstage. Instead, it is wisely tuned for a somewhat smooth, forgiving presentation up there, where errors of omission don't distract. The Veritas is far more capable in that aspect, resolving gobs of details the Oppo misses. On the other hand, one might think the Oppo would posses a natural advantage in things like bass slam and dynamic authority - hallmarks of a stout, well regulated PSU. Yet Veritas keeps up and even surpasses the Oppo in its theoretical strong points.

The conclusion here is that you can go a long way with more "traditional" audiophile design concepts, as Exemplar has done on this device, though forward thinking engineering with a strong focus on the digital side can surpass those achievements. Obviously this doesn't always happen, but in this case I'd say it does.



PS Audio DirectStream Junior ($3999)
I have a mixed history with PS Audio. Some of their gear has left me totally cold (the Sprout, and the original NuWave for example, neither of which I enjoyed in the least), while others I've quite liked (the PerfectWave DAC and transport as well as the older Digital Link III). Even when I do enjoy their stuff, I tend to find it overly expensive - the flagship DirectStream falls into that category. It's an excellent sounding DAC, but even so, $5999 seems a bit steep.

The DirectStream Junior cuts that price by $2K while sounding nearly identical to my ears. There is a difference, but I find it small enough not to matter for the vast majority of listening. Junior also adds network functionality with Roon compatibility which is a huge deal for me. Users of the big DS Senior need to purchase the Bridge II separately to get this same feature, to the tune of $899. So realistically the Junior saves almost $3K compared to a similarly equipped Senior model.

On sound, I find the Junior highly enjoyable. It actually sounds quite similar to Veritas in a lot of ways. Both do cymbals and brushwork in a very convincing manner. Both have very open, airy presentations, with Veritas taking a slight edge in terms of specificity and soundstage depth. Both dig extra deep on the low-end, being authoritative yet uncolored by unnecessary exaggeration. And both can do massively complex orchestral works without breaking a sweat.

Where I found them to deviate is with regard to detail. Veritas is a bit more focused on micro, while Junior has more of a macro-oriented presentation. This initially led me to find Veritas brighter and Junior more dynamic - a good summary which doesn't really capture the whole truth. After much more listening, I don't think Veritas is necessarily brighter so much as it is more incisive with the tiniest details. And while the Junior is certainly dynamic, it doesn't really do much that Veritas doesn't do... it's just the focus is shifted based on the different signatures. They both sound excellent in their own slightly different ways.

In the end I could happily live with either of these devices in my reference system. Veritas is more affordable at first glance, but to match the Junior with Roon streaming I need to factor in my SOtM sMS-200 powered by the Wyred 4 Sound PS-1 - which brings the prices pretty much in line with one another.

While stepping up to the top PS Audio model costs lots of money for minimal gain, Resonessence Labs offers substantially more when upgrading from Veritas to Invicta Mirus Pro. But that's a story for another day.


Auralic Vega ($2799)
Vega is a very popular and well known DAC, which most people seem to respect - even if they don't quite love its signature. Until recently, it sold for $3499, but with the new price cut it matches the Veritas almost exactly. Technically speaking, this is probably a soon-to-be-discontinued item, as Auralic has the new Vega G2 coming down the pike. That model will cost substantially more ($5600) putting it in a whole different class. Many Vega users can't or simply won't go that high.

Still, the original Vega is an enjoyable device with plenty of life left in it. It's got a quicksilver presentation with what I initially hear as extreme amounts of detail, along with a slightly lean but wonderfully textured midrange and textbook low-end accuracy. No doubt about it, this is a high performance device.

I mentioned how I "initially" thought the detail levels were higher. After lots of listening, I've determined the Vega does some interesting things in that area. There's a bit of an artificial "push" to it, where the device seems to be trying overly hard to produce extreme clarity. It works pretty well at times, and often sounds stunning on demo tracks or during quick listens. I can see people being easily sold on this device when auditioning at a dealer.

When you get it into a familiar home system and spend more time listening with well-known tracks, something else begins to emerge. I get the impression of a sort of unnaturally "forced" feeling on the upper midrange and highs when using Vega. It's like the DAC is trying really hard and straining itself in the process. I know that's a weird description but it's the best I can do. Individual notes still come out clean enough, but somehow the entire thing doesn't sound natural when taken as a whole. Veritas does not suffer this problem at all.

The best analogy I can think of - and it's still a flawed one, to be sure - is listening to pop artists like Kelly Clarkson, Pentatonix, Dami Im, etc. Beyond all the vocal processing and studio trickery, these folks are still quite talented as singers. But in my humble opinion they all try way too hard much of the time. Listen to Kelly Clarkson's Christmas album Wrapped in Red and you'll hear exactly what I'm talking about. She goes pedal to the metal far more often than one would expect - which doesn't exactly fit with some of the material on this album. It sounds impressive at first but gets old rather quickly. I suppose when you came up competing in talent shows, you become accustomed to showing off a bit. Or maybe I'm just an old curmudgeon and this is how things are done these days.

In any case, the Vega similarly strikes me as trying too hard at times. There's clearly talent on board yet the presentation gets tiresome after a short while. This gets worse when using HD800 or JH13 or other easily-excitable transducers. Veritas does not suffer this same problem. I can listen for hours without fatigue, while not feeling like I missed out on detail in any way. In fact, head to head, Veritas resolves more cleanly and naturally than Vega. It just doesn't call attention to itself in the same way.

I also find Veritas less finicky from an operational standpoint. Vega demands warm up and sounds best in "exact" mode which doesn't always play well with every source. Even using "sleep" mode to power down, it still requires some time prior to sounding its best and achieving "exact" lock. I've also had some driver weirdness when using a Surface Pro 3. Lastly, I hear subtle differences depending on which input I use. In contrast, Veritas has been rock solid via USB with even the most pedestrian laptop, and sounds pretty much indistinguishable regardless of input - it will showcase transport quality, but all inputs have roughly the same potential to shine. Veritas doesn't have a power button at all, instead relying on a standby mode which seems more effective than Auralic's sleep mode. It's ready almost immediately.

Vega owners who find themselves falling out of love with their DAC should absolutely consider Veritas as an alternative. The signature is similar enough that it won't throw a carefully tuned system out of wack. Yet the benefits of such a move are clear - more natural sounding transients, less treble grain, improved soundstage depth and layering, and a bit more tonal richness without overdoing it.


COS Engineering D1 ($9000)
This is a big, beautiful device that sounds rather nice, but just doesn't really do anything well enough to justify the price. It's a sweet, almost "soft" sound that I'd call unobjectionable at best and boring at worse. It's not as clinical as many of the more affordable options in this roundup, and would probably pair better than most in a wider variety of systems. It's also got a really well done enclosure befitting the high price. Does it sound like I'm damning this thing with faint praise?

Price aside, I prefer Veritas over the COS device hands down. It's got an incisive, focused sound that really brings out more of the performance, while the D1 meanders about sounding inoffensive or perhaps "charming" if I'm being generous. I would understand it more if they went full-bore warm and smooth, or lively and exciting, or some enjoyable coloration. But they seem to have settled on a generic sound which excels at nothing. I'm thinking this might work well with some of the older Audio Technica woodies, maybe paired with a warm tube amp or something. That's about the best I can come up with.

I won't bother going on any further on this one, other than to point out the lack of correlation between size, price, and results. Veritas is much more compact and affordable yet does better in pretty much every performance metric, unless we count "imposing looks".


Ohers
I've had several more DACs pass through the system recently, but for one reason or another I didn't get a chance for direct comparisons. I will comment briefly just in case that helps anyone in some way.

The Arcam D33 was surprisingly competent despite a plain appearance and lack of DSD support. At $3200 it's surely overpriced but deals can easily be had for significantly less. The exaSound e22 actually sounded very similar to the Arcam - neutral, precise, and accurate - while adding DSD and headphone output for around the same price. I strongly suspect I'd prefer the Veritas more than either of those models, which are a bit more dry and clinical, but I can't be sure without direct comparisons (which are unlikely to happen any time soon). I had the Bryston BDA-3 ($3500) here briefly and didn't care for it at all, so that went back to the sender right away. Suffice to say I very much prefer the Veritas.

Just so you don't think it's all rainbows and sunshine for Veritas, I've heard some tough competition as well. The Matrix Audio X-Sabre Pro is very impressive. For $1700, it's quite probably the DAC to beat in my experience - I found myself extremely satisfied with the sound it produced. Not to mention the build quality and feature set which are vastly beyond most DACs anywhere near its price. Unfortunately a direct comparison just wasn't in the cards before my time was up. By indirect comparison, I'd say the Matrix unit is a bit more lively, exciting, and "punchy" sounding if that makes any kind of sense. Veritas is more neutral and natural, with slightly better soundstage reproduction. But again, going from memory on these things is fickle, and I wouldn't put too much stock on this comparison.

Another very strong contender would be the Exogal Comet Plus ($3500). It's a somewhat warmish, "analog" sounding DAC which I absolutely loved when I had it here a while back. It's integrated headphone output isn't very useful, and I'm not sold on its use of bluetooth for remote control via smartphone. The display is tough to see as well, depending on the lighting in your room. But those concerns melt away when I hear its beautiful sonics. This is probably one of my favorite DACs of all time, and I'd happily run it as my "one and only" - it's that good. As far as comparisons with Veritas, I would think each model appeals to a different type of listener. Veritas is a neutral reference while the Exogal, like my BMC UltraDAC, gives a small but noticeable helping hand to everything you play. Different systems would favor one device or the other, and I can't really see anyone having a tough time deciding - depending on ancillary equipment, the choice would be pretty clear.

I wish I had more time to spend with popular models like the Schiit Yggdrasil, Holo Spring, and Oppo Sonica. All three models sound promising but I haven't spent nearly enough time with any of them... and most of my listening was elsewhere in unfamiliar systems. Which again makes it very difficult to draw any meaningful conclusions. I'm intrigued by the oddly named Denafrips products, and the upcoming Soekris 1541 looks like a killer product for the money. But I've already delayed this write-up several times just to get "one more" comparison done. If I keep waiting until I hear everything I want to hear... I'd never finish. So here we are.


Conclusion
I can't say the Resonessence Labs Veritas is the absolute best DAC priced at or near $3,000. I just haven't heard all the competition to be confident in that claim. That said, I have heard quite a few, probably more than most people, and I'd say Veritas ranks very highly in that space. The only alternatives I might consider involve very different sound signatures, which have better synergy in certain systems.

For a neutral, reference sound with spectacular soundstage, incredibly precise imaging, and clarity that one rarely finds at any price, Veritas earns a very hearty recommendation.

Problem - computers are noisy, messy things. Multiple fans. Tons of background processes. Data flying every which way through a variety of system buses. The end result can be great for playing the latest first-person shooter, but not ideal for high-quality audio reproduction. Plus - have you tried fitting a PC or laptop into an audio rack? Historically, it isn't a great fit.

Solution - attack from multiple angles. Add a USB widget to clean and reclock the output. Run dedicated playback software instead of the baked-in player that came with your OS, and maybe an optimization app to help clean up the OS even further. The resulting system might be a PC running Foobar and JPLAY, plus an Uptone Regen cleaning up the outgoing USB signal. This is a pretty good solution overall, and with the right DAC can challenge some rather expensive CD players.

Downsides? Yep, a few big ones remain. Fan noise, big/ugly (or both) enclosure, and even price in many instances. You're paying for a lot more power than you need, while still not getting everything you want in other aspects. The last few generations of the Intel NUC devices solve the size issue while remaining vaguely ugly in their own way, and can still be just a tad noisy to my ears. They aren't as cheap as I'd like either. And of course sound quality on that USB output will only go so far. I guess it's fair to say that while some welcome progress has been made in this arena, a general purpose computer still isn't ideal in a high-end audio system.

If you've got lots of money to throw at the problem, a dedicated music server is the usual recommendation. Pick an Aurender, Naim, Lumin, Music Vault, Linn, Antipodes, etc, and you'll be in business. What's that? You can't (or simply won't) spend at least a few thousand dollars on this solution? Then these options are off the table. Also, many of them don't do Roon, which is absolutely essential as far as I'm concerned.

Few options remain. After trying most of them, I've found one that I absolutely love - the SOtM sMS-200. Until now I've associated SOtM with the high-end sMS-1000SQ which isn't exactly affordable, even in base form. The sMS-200 is something else though - a network audio player which sells for just $450.



The Design
The sMS-200 is a custom built playback device with a focus on sound quality over versatility. That means just a single Ethernet input and a dedicated high-quality USB output. No wireless connection, no built-in DAC, no display, no legacy SPDIF outputs. Well, SOtM does give us a pair of USB inputs for adding storage to the system, but that's about it for extras (and I don't use those anyway). The whole point here is to send audio from point A to point B as cleanly and unobtrusively as possible. Store your library on a PC located elsewhere in the home, ship music via network over to the little SOtM for ultra-clean playback, and keep all that noise - physical and electrical - out of the listening area. All for what I consider a fairly reasonable price. What more could I ask for?

I know it's all about the sound, but looks actually do matter for a lot of us. And the sMS-200 looks quite appealing to these eyes. The enclosure is small enough to fit most anywhere, with interesting angles that set it apart from the usual audio box. At the same time it isn't really trying too hard to look "HiFi" if that makes any sense. SOtM has a whole line of other gear in the works using this same enclosure, which I feel looks superior to their prior series of small-box products.



While being very single minded in terms of hardware features, the sMS-200 does have a lot of options on the software side. SOtM runs a custom Linux build which gives a full alphabet soup of available modes: MDP, DLNA, Squeezelite, Airplay via Shairport, and HQPlayer NAA. I like having so many options but I'll be honest - I didn't really use any of those beyond testing to see if they work (they do). No, the main draw for me is Roon Endpoint capability. I run Roon server on another machine hidden in a spare room, which serves up tunes to the sMS-200 in my headphone rig. Over 100,000 tracks available, with easy setup, and smooth playback that has yet to glitch during my extensive testing. And did I mention exceptional sound quality?



Listening
Throwing the sMS-200 straight into my rig using the stock wall-wart power supply, I was very impressed with what I heard. Most of my listening was done with the Resonessence Labs Veritas DAC but I also tried out a Simaudio 430HAD, Cayin iDAC-6, Mytek Stereo 192, Esoteric D-07x, and B.M.C. UltraDAC. In each case I experienced beautiful results, with a clear edge over what I get when running straight from my PC or MacBook. The rest of the system components, for those interested: Equi=Core 1800 balanced power conditioner, Cabledyne Silver Reference cabling, Pass Labs HPA-1 headphone amp, and a bunch of headphones including HD800, LCD-3, Dharma, HE-1000, K812, and others.



With the sMS-200 in place, I get tighter low-end definition, superior imaging, and a liquidity to the treble that just isn't revealed by the more pedestrian transports. It's noticeable to the point where I'd be willing to pay some pretty good money for an improvement of that size. It was pretty clear during critical listening, but probably even more beneficial over time - music was more engaging yet natural, and therefore not as likely to induce fatigue over the long term. Kind of hard to put it into words... but I know it when I hear it, and I suspect many readers have experienced this same thing after a successful component upgrade.

The improvement was pretty consistent across the board, with the exception of the Esoteric which showed a disproportionately large jump in SQ. That particular USB implementation seems pretty sensitive to transport quality and the SOtM pushes it over the edge from mediocre to pretty good - specifically in the key upper midrange and treble area where the D-07x tends to struggle. It's still not a great DAC, despite the high price, but with the sMS-200 I'm able to enjoy it for the most part.



Let's be clear - this is not a glaringly-obvious upgrade on the same level as getting better headphones (or speakers). Swapping transducers is by far the largest upgrade one can do, followed by room treatments in the case of speaker listening (for most rooms, anyway). Those can drastically impact sound such that even a casual observer (friend, spouse, child, etc) will notice. I won't pretend the addition of a better source makes such a massive, transformative contribution to the sound.... in my experience, it just doesn't, and reviewers making such claims are exaggerating a bit. What it will do is help you get the most of the DAC you already have, along with any DAC you might try out in the future. It brings improvements in imaging, treble refinement, low end weight, and a general sense of ease I don't hear with a regular computer at the helm. So, small differences in a way, but pretty significant depending on how you look at it.

I also need to point out how different systems can be more or less equipped to take advantage of a superior source. When I run the Resonessence Labs Veritas, feeding a Pass Labs HPA-1, driving a resolving headphone like HD800 or EnigmAcoustics Dharma, I feel like the upgrade from laptop to sMS-200 is fairly obvious. Most people could probably pick up on it after a bit of serious listening with familiar material. Switching to my Cayin iDAC-6 running in tube mode to the Cayin HA-1A MK2, and driving a Sennheiser HD650... the difference is less obvious. This is still a very enjoyable system but the emphasis is more on tonal density and harmonic richness than soundstage or microdetail. I wouldn't be surprised if most people wouldn't notice the upgrade, or at least not without really straining to hear the difference. Personally, I still find the SOtM more convincing, but it's admittedly a smaller improvement and not as important in the grand scheme of things.

So, having established these aspects, I'll now submit that the convenience, size, and looks of the little SOtM still make it worthwhile to me - even in a system where the SQ improvement is modest. Fitting a laptop into either of my audio racks is not ideal. Neither is laying a big tower PC sideways. And most computers get louder than I'd like - I'm very sensitive to fan noise. Also worth noting is the fact that neither my MacBook or my PC sold for anywhere near $450 when new. For that money, the sMS-200 covers all the bases, without any extraneous functionality that isn't needed in this context. I call that a success.



Quick Comparisons
Based on my somewhat limited testing, I do find the sMS-200 preferable to the Sonore Sonicorbiter SE and microRendu, though I'm not confident enough to get into specifics on those comparisons. Aesthetics is an obvious win for SOtM, but I think it takes a very slight edge in sonics as well. The microRendu comes very close but sounds a little "boxed in" by comparison, for lack of a better term. Again, I can't go too much deeper into this, other than to say the SOtM would be my first choice after considering sound, price, and appearance.

I've spent time with Auralic's Aries streamer in the past, though not at the same time as the SOtM. The Aries strikes me as a different animal - the emphasis is on its large feature set rather than the core sound (which is still pretty enjoyable, don't get me wrong). When running as a Roon endpoint I'd take the sMS-200 every time. If I wanted to use a different mode and play straight from the device itself, sans Roon, I think the Aries is probably better equipped to parse a massive library. The SOtM does fine in MPD mode with a sensible music collection but did stumble when trying to parse several terabytes worth. But again, I haven't done enough testing to really flesh this out fully.

The Aries Mini doesn't have Roon, so it's off my list entirely. Too bad. That would make an interesting comparison considering the similar pricing.




Upgrades
So far so good, but what if we want to take things a bit further? As is often the case with all things audio, power supplies matter. A lot. For those with a suitably resolving system, replacing the bundled wall-wart is an obvious path forward.

As I write this, SOtM is still putting the finishing touches on their matching PSU. You can get their older mBPS-d2s battery-based power supply and from what I've read it works just fine, but the aesthetics are off compared to the sMS-200. Since the "correct" PSU isn't done yet I went in a different direction and tried the new PS-1 from Wyred 4 Sound.



I'll have a full write-up on the PS-1 soon enough (EDIT: here it is), but to sum it up - this is a modular design that accommodates up to four add-on cards, each capable of running at a different voltage. In my case I used their high-current module to power the sMS-200, as it draws too much juice to be used with the standard amp module. (EDIT: I've confirmed that the Standard amp module is perfectly adequate when using the sMS-200 as a Roon endpoint. Using it in MPD mode with attached hard drives might still need the High Current module, but Roon mode is fine with the regular/more affordable module).

The other typical tweak for these things involves adding a device to help clean up the USB output. For this I used a Wyred 4 Sound Recovery, powering it with another separate module inside the PS-1. Now, the sMS-200 is already quite good in terms of USB output, but I was trying to stretch its legs and see just how far it can go. The answer? Surprisingly far.

Let's tally - sMS-200 is $450, Wyred 4 Sound PS-1 is $399, plus a high-current card at $500 and a standard card at $125, and don't forget the little Recovery at $199, for a grand total of $1,673. Not at all what I'd call cheap, yet still far from the big leagues - my Aurender is $3,499 and my B.M.C. goes for $5,780. Could the souped-up SOtM, no longer a compact/simple add-on device, really compete at that level?

It sure can. I was shocked to hear the sMS-200 keep up with these far more expensive options. The linear power plus the USB treatment really brought things up several notches - again, it takes a high-end system to showcase this, but it's definitely there under the right circumstances. There are some areas where the SOtM gives ground here or there but generally speaking it is not left behind by the more expensive devices, and in some ways even surpasses them. That's highly impressive for a package costing well under half as much.

To flesh that out a bit more - the SOtM/Wyred package brings superior imaging and a more three-dimensional soundstage when used with a system capable of showcasing those traits. This was most obvious when using HD800 or my Stax rig, and even more so when I threw it in my speaker setup. Bass weight improved as well, yet it was the openness of the sound that really sold me on the impact of the PSU upgrade.



My speaker setup uses a BMC UltraDAC and a pair of Merrill Audio Thor monoblocks, driving Usher Dancer Mini One DMD speakers with their extremely revealing diamond tweeters. I normally run the BMC PureMedia as transport along with their PureUSB1 active USB cable, and it sounds beautiful. Switching to the SOtM/Wyred shifted the focus to a more ethereal presentation with improved depth and three dimensionality, at the cost of some midband richness and perceived "oomph". To use cliches, the PureMedia could be called a more stereotypically "analog" presentation, while the SOtM/Wyred rig made a more detailed, open sound commensurate with digital-done-right. Which one you prefer comes down to your taste and associated equipment. I'm just impressed to find them so evenly matched given the price disparity. If the upgraded sMS-200 can keep up with my BMC and Aurender, I have no doubt it would do the same when compared to other streaming devices I've experienced in the $2k to $6k range, and likely beyond.

Again, I have to stress that some DACs showcase the power supply and USB treatment improvements more than others, so results may vary... but in most every case I tried, there was at least some improvement over the basic sMS-200 sans extras. Which itself was, as I said earlier, already an improvement over the MacBook Pro.


Conclusion
While I'd happily put my Resonessence Labs and BMC reference DACs up against any sonic competition, I have to admit I find myself envious of devices from PS Audio (and others) which have built-in Roon-ready network streaming. That removes the need for another component in the chain, potentially saving quite a bit of money along with the space and system complexity required for a separate component.

That's why I'm pleased to see a well executed device like the SOtM sMS-200 come to market. It basically turns any DAC into a networked device, complete with Roon and several other options, for under $500. The sound is excellent even in stock form, the appearance is highly agreeable, and it doesn't take up much space either. I quite happily recommend this little thing in stock form.

If the user has a desire for even better sound, the sMS-200 scales wonderfully with power supply and USB output upgrades. Those on a limited budget are free to add one thing at a time, netting incremental upgrades until the final destination is reached. Did I mention the end result punching way above what the price would suggest? I have absolutely zero hesitation about running this thing with the Wyred 4 Sound add-ons in my reference rig, displacing much more expensive components. In fact, that's just what I've done. So long, Aurender.

Imagine yourself in charge of a traditional HiFi speaker company - a segment where sales are trending relatively flat (or worse) for the past decade or so. You look at the market and salivate at the rising sales figures of the "personal audio" category, pondering how you might get a piece of that action. Slowly, cautiously, you begin having your team translate their design prowess from speakers to headphones, under the assumption that they have a lot in common - it certainly makes more sense than designing turntables (the other hot category at the moment).

If this sounds too measured and reasonable, an alternate version has the boss sending excited emails: "Headphones are hot! I want a set of our headphones on store shelves within the next 6 months!!"
I suspect one of these scenarios has unfolded numerous times throughout the audio world; hence recent launches of headphones from KEF, Polk, Sonus Faber, PSB, Focal, Paradigm, Bowers & Wilkins, and Klipsch, with plenty more to follow.

It was only a matter of time before a similar scenario took place on the amplification side of things. Why should brands relatively unknown outside of headphone circles - Woo Audio, Violectric, Cavalli, and Eddie Current among others - have all the fun? Thus we now have dedicated headphone amps from the likes of Pass Labs, Bryston, ModWright Instruments, and Manley, just to name a few, with more certainly on the way as time passes.

Well, now you can add veteran Canadian firm Simaudio to the list. Their Moon Neo 430HA sets out to offer world class heaphone amplification along with preamp and optional DAC duties, all in a very traditional Simaudio enclosure. Ever notice how a lot of headphone amps are oddly sized and/or shaped? The 430HA fits right in with the entire line of Simaudio Neo products, and wouldn't feel out of place in most any proper audio rack stuffed with full-size audio components.




Let's clarify before we go any further - the "base model" 430HA is a $3,500 beast purely dealing with analog ins and outs. Adding the optional DAC board brings the cost up to $4,300 and updates the name to 430HAD. Or, at least that's what I've seen it called all over the web. And it makes sense - D for Digital, right? Thing is, I don't see that extra D mentioned anywhere in Simaudio's technical papers, nor have I ever seen their marketing actually use the term. Go ahead, check their website - you won't find it. So, I'm going to resist the urge to use what is essentially a nickname at this point, but I will be discussing the DAC board since I feel it is one of the strong points of the product, regardless of moniker.

Let's talk versatility. Perhaps owing to it's relatively large size compared to many headphone amps, the 430HA has a generous amount of connectivity. Remember, this thing can be a full-fledged pre-amp as well, so the more choices the better. We get three analog inputs - two RCA and one XLR - along with a pair of RCA outputs in fixed and variable form. On the digital side there's a Toslink jack, a pair of coaxial inputs, and the ever-important, DSD-ready USB port. Less likely used but still potentially helpful are the proprietary SimLink ins and outs (for pairing with other Simaudio gear) plus a 12V trigger out, IR input, and RS232 for custom integration. That's already quite a bit and we haven't even covered the actual headphone jacks - ostensibly the most critical aspect of a device like this.





At first glace, the front panel looks simple - just a standard 1/4" headphone out, plus a little 1/8" input for quick use with iPhones or other portable devices. Take a closer look and... you probably still won't see anything beyond that. But wait - what's that little nub just left of the 1/4" jack? Sliding it left (with a buttery smooth action I might add) reveals balanced headphone outs in both 4-pin XLR and dual 3-pin XLR format. That means the 430HA handles every common headphone termination short of specialty stuff - I'm talking balanced connections on the Astell & Kern, HiFiMAN, and Pono devices, where each brand uses their own unique type. But as far as the vast majority of gear goes, Simaudio has us well covered.










Internally, the 430HA is just as ambitious. Simaudio describes it as a "fully balanced, pure analog amplifier" using a "discrete transconductance circuit topology". The power supply features two shielded torroidal transformers, 35,000uF worth of capacitance, and a total of 7 stages of voltage regulation. Design inspiration is taken from Simaudio's Evolution series models such as the 740P preamp ($9.5K) and the 810LP phono stage ($12K). That's not bad company to be in.




Significant engineering was brought to bear on the volume control - an absolutely critical aspect of any high-end headphone amp. It usesSimaudio's proprietary M-eVOL2 design, again borrowed from other tried and true models in the Simaudio portfolio. This essentially boils down to a pair of current steering R2R ladder DACs on each channel (so four total, as is befitting a true balanced design) to vary the amplitude of the signal. It gets a bit complex but just know that the audio signal remains in the analog domain at all times, unlike some digital attenuation schemes which throw out bits as the volume drops. The end result here is an obscenely black background, essentially perfect channel matching, and 530 total steps in .1dB increments. It's a brilliant execution that you really have to "feel" for yourself to fully appreciate.




Expensive headphone amps should give correspondingly high performance, and that's the context in which I judged the 430HA. On the plus side, this thing drives any pair of headphones you can throw at it without breaking a sweat. It's capable of dumping 8 watts into 50 ohm loads, yet delicate enough to drive sensitive IEMs without unwanted noise. That last bit is a serious difficulty with powerful desktop amps, and is often overlooked in many reviews. Lots of amps are powerful, but a silent background and ability to drive very sensitive IEMs well is a mark of excellent design. I mean it - this thing works with any headphone except electrostatic models (of course).

Now, you've no doubt heard that statement in reviews of other headphone amps from a variety of publications. Those reviewers likely then proceeded to list the 3 or 4 or 5 headphones they used to arrive at that conclusion. Which is cool - that seems thorough enough right?

Me, I like overkill, so I tested no less than a dozen headphones on this thing, plus a half-dozen in-ear monitors just to seal the deal. I tried everything from the 600 ohm beyerdynamic T1 to the AKG K3003 which dips down into single digit impedance. I used some balanced-armature-based custom IEMs with sensitivity in the 120dB range, and then switched to the HiFiMAN HE-6 rated at just 83.5dB. I used cables with 1/4" termination,1/8" plus adapter, 4-pin XLR, and even dual 3-pin XLR which is a style I thoroughly dislike. Through all this I can say the 430HA never missed a beat. That volume control is superb - I never once found myself unable to dial in the perfect level for a given headphone or IEM. There are two gain settings (14dB and 20dB) but I found that the lower option worked for me 99% of the time.





Surprisingly, I also quite enjoyed the selectable crossfeed option. Crossfeed is a method of blending information from the left channel into the right channel and vice versa, with the intention of creating a more natural sound. Headphones, by nature of their design, completely isolate the signal going to each ear. This can take away their sense of realism at times - especially if you're mainly accustomed to speaker listening where the channels obviously mix before hitting the ears. There are many ways of implementing crossfeed and much of the time I find it more obnoxious than helpful.... it tends to collapse the soundstage and make the timbre all wonky, while the "natural" effect it strives for never really materializes.

In this case I find it actually listenable. No, scratch that, I find it pretty damn convincing. It's not too strong but not too subtle either. It doesn't change the tone of Lee Morgan's trumpet. It's not dark and compressed. All of these things I've heard from other attempts at crossfeed, so I'd call Simaudio's implementation a success. Nothing's perfect though, and I do hear a somewhat diminished sense of imaging in exchange for the "out of head" sound being produced. Image specificity is a bit hazy and indistinct compared to what I'm used to, though I suspect speaker listeners might not agree. Headphone listening is, after all, something of an acquired taste, and I'm so used to the standard presentation that I may not be the best judge of something like this. For speaker listeners, the crossfeed circuit may well be preferable even in the imaging department. Me, I still use it off and on, especially with hard panned older jazz and classic rock material.

By now I've established that the 430HA has no shortage of power, while retaining the delicacy required to successfully drive IEMs. I've also praised the crossfeed implementation as one of the best I've heard. But aside from that, how does this thing sound? Why am I dancing around on that stuff when I have yet to paint the sonic picture of how this amp is voiced?

I suspect my delay is related to the mixed feelings I have. On the one hand, this amp does numerous things right. In some aspects - volume control, connectivity, and the ability to drive any headphone - it may well be the best headphone amp on the market today. It's an incredibly well-built amp with a thoughtful design, using quality parts, and it comes from a veteran audio firm with enormous pedigree. Which is why it's difficult to admit, but the actual sound signature of the amp itself just isn't what I hoped it would be.




To my ears, across a wide range of headphones, the 430HA has a powerful sound which I'd describe as "musical". There's a distinct warmth involved - from Gary Karr's "1611 Amati" (which turned out to be neither) to Pastorius and Mingus, and forward in time to well recorded electro from Mr. Oizo, Infected Mushroom, and Photek, the 430HA has low end guts very few competitors can match. If you like a healthy does of sledgehammer-in-the-face, this amp can certainly do that. If you like beautiful, nuanced, full-bodied tone, it can do that too. If you want a more measured and delicate response without any added warmth whatsoever.... the 430HA isn't necessarily the best match. It wasn't so obvious at first but the more time I spent with it the more I realized this coloration was always present. Did it make the music sound more enjoyable at times? Absolutely. If it was just this one bit of coloration I probably wouldn't complain. Problem is, the warm signature doesn't stop there.

Detail retrieval is what I'd call good but not great. It helps to have that inky black background, and with some (many?) headphones it seems to unlock all the resolution they are capable of producing. But with a Sennheiser HD800, an AKG K812, a HiFiMAN HE-6, or a Jomo Audio 6R IEM, I get the impression some detail is being glossed over. I'm all for warmth and smoothness but this goes just a bit far for my taste. The resulting sound is a bit slower than I'd like, and not really as transparent as I would have expected either. Piano and strings in particular just don't have the proper sense of bite required to sound totally convincing. Female vocals are generally acceptable but at times feel a bit lacking too. This would be fine for a tube amp where I had options to roll in a different signature if desired. But on a reference caliber solid-state amp I guess I just expected more transparency.

And that's where my complaint gets complicated. You see, I actually quite enjoy listening to the 430HA in the right context. Paired with the very neutral Anedio D2 DAC, and driving the HiFiMAN HE-6 which is occasionally bothersome in the treble range, I find the resulting sound to be very listenable. Or, switch out the Anedio for the Resonessence Labs Invicta Mirus Pro (using the spectacular new ES9028Pro DAC chip), and maybe swap out the HE-6 for the analytical Sennheiser HD800, and again we get a system I could jam to all day. Trouble is, I don't feel it's quite worthy of the high price tag - I can definitely assemble a similarly musical system for less dough. It's frustrating that although the amp will happily drive any headphone in existence, it won't necessarily have the proper synergy with each one. In fact I'd say there are more misses than hits overall - any somewhat darker headphone just isn't a good match in my book.




What's the deal here? Is this amp just a failure? How did that happen? I'll come right out and say that I feel Simaudio voiced this amp for speaker-listeners. It seems very intentionally designed to avoid listener fatigue, which can be a big issue when the distance from transducer-to-ear drops from 12 feet to about an inch. When that happens, the amount of micro detail coming through grows significantly. That album which you've always found ever-so-slightly bright on your speaker rig? It can become intolerable if you're not used to anything but speakers - even on a system which headphone aficionados would call "neutral".

My theory is that Simaudio had this very thing in mind when putting the finishing touches on the 430HA. Compared to other "reference" style amps such as the Auralic Taurus MKII, the HeadAmp GS-X MK2, or a pair of Questyle CMA800R amps in dual-mono mode, the 430HA sounds a bit slow and - as much as it pains me to say this - almost boring in a way. Yet those amps might be seen as overly bright or aggressive to ears more accustomed to speaker listening. Which, I'll happily admit, is not the demographic I fall in to. So the thought occurs to me that this may well be an issue with my preferences and expectations rather than a real deficiency with the amp itself. I suppose it's a matter of perspective.

My experiences with other Simaudio gear throughout the years gave me certain expectations. I loved every amp of theirs I've encountered, from their entry-level integrated units to their big Evolution amps. In contrast, I've never really clicked with their digital stuff. I've owned or auditioned various CD players of theirs in the low-to-mid range and even tried some of the (rather expensive at the time) DVD players like the Stellar and Orbiter back in the early 2000s. None of it was terrible but neither did it strike me as being anything special in a sea of worthy competition. I really wanted to love them based on my history with Simaudio amps - but I just couldn't.

So you can imagine my surprise when the amp section of this dedicated high-end headphone amp didn't blow me away, yet the $800 add-on DAC section managed to stand out as being a huge success. Seriously... most add-on DACs begin at "forgettable" and go downhill from there. Not this thing. It's got excellent resolution, impressive imaging, and a tonal balance that just works. I'd happily put it up against any sanely priced DAC I've heard in the last few years.





And that's not just hyperbole. Direct comparisons are easy thanks to the multitude of inputs/outputs on the 430HA, so I took the opportunity to run it through its paces with a few other units I have on hand. Compared directly to the Woo Audio WDS-1 ($1,195), the Simaudio DAC is more open and airy sounding, with a much more believable top end. It's not even a close contest. The M2Tech Young DAC ($1,695) has a touch more midrange liquidity, and thus initially seemed more organic than the relatively matter-of-fact Simaudio DAC. Yet after much back and forth I discovered the Young doesn't satisfy in terms of bass impact and texture. It sounds loose and sloppy where the Simaudio is very tight and impactful. And again, that Simaudio top end is so clean, making the otherwise respectable M2Tech unit seem a touch dull in comparison. Out of these three models I would choose the Simaudio DAC every single time.

I suppose it's an unfair comparison though. The DAC card only "costs" $800 but ends up piggybacking on the existing power supply and output stage. Which means it would cost quite a bit more if offered as a stand-alone product. In any case, you'll have to move up to something substantially more costly to improve on this experience - an Auralic Vega or an Exogal Comet Plus for example. Unless you already own or have plans to own a REALLY nice stand-alone DAC, I'd say go for the built-in option and simplify your system. It's that good.

As a preamp, the 430HA is about on the same level as the DAC. Which is to say: highly satisfying, though in this case I'm not surprised in the least. I have less experience with Simaudio's line-stage gear as compared to their DACs and amps, but what I have heard I've really enjoyed. The most recent example I had in my system was the Moon 350P from just a few years back. It was their most affordable preamplifier at $2,500 and did a bang up job in that class and beyond. Despite being primarily focused on headphone amplification, the 430HA is easily just as capable a preamp as the 350P - perhaps even a bit better as far as purity of sound. It does give up a bit in terms of inputs/outputs but makes up for that in transparency. Not to mention that volume control which is so much more satisfying to use. The 350P volume control was perfectly fine but the 430HA feels much more precise and, in a word, expensive. Unless you absolutely need all those extra ins and outs, the 430HA is hands down the better preamp.




Conclusions
In the end, I am somewhat torn on the 430HA. I love the look and feel of it, and very much enjoy the crossfeed option too. I could easily see using this thing as the heart of all but the most complex system thanks to its generous connectivity options. It would sound great as an integrated DAC and preamp, being very competitive in those areas. If I was shopping for that sort of device in the sub-$5K range I would certainly consider this device regardless of the headphone aspect.

Having said all that, I'm not completely sold on it as a reference class headphone amplifier. It just seems to lack the level of transparency I crave. Mind you, it's still an excellent headphone amp - superior to the BHA-1 from Canadian competitor Bryston ($1,695) to name one example. But for $3,500 I expect to be blown away and in this case it just doesn't happen. I prefer the warmth of my Violectric V281 which doesn't sacrifice detail in the process, and doesn't cost as much either. And the Pass Labs HPA-1 is clearly the better amp as far as I'm concerned (though, as with the Violectric, you lose out on the non-headphone related features compared to the 430HA).

I admit to being in the minority here. Headphone maestro Tyll Hertsens raved about the 430HA as have many others in the community. Then again, Audio legend Bob Katz described the 430HA as "overly soft" so I know I'm not crazy. Perhaps this is ultimately one of those products like the Chord Hugo and the Beyerdynamic T1 where you really need to try it for yourself to judge. Where I hear a lack of transparency and finesse, others may very well hear a speaker-like, fatigue-free presentation unique among top solid-state headphone amps.

Despite my misgivings, I'm still thrilled to see a company like Simaudio take the plunge into headphone gear. They recently launched a sibling model dubbed the 230HAD which is a smaller integrated DAC/headphone amp without the balanced outs. At nearly 1/3 the price of a DAC-equipped 430HA, that could well be the product I was looking for all along. I definitely look forward to taking it for a spin one of these days.

Have you tried Roon yet? I haven't written much about it thus far, but to be honest it's sort of a game-changer in my view. Now any company wanting to make a streaming audio device can avoid the massive headache of designing their own user interface - as long as they can work out the licensing details with Roon Labs of course. UI is a frequent challenge, with otherwise excellent devices only earning "cautiously recommended" status thanks to their cludgy controls. Even Aurender, with their very well thought out Conductor App, can't compare to the joy of Roon.

This isn't strictly a Roon review though. The idea here was to find a really affordable way to integrate Roon into various zones in my home, feeding into a modest external DAC over SPDIF. Sure, I could spend $300 on a Sonore Sonicorbiter SE, but that's still a bit rich for occasional use such as a spare bedroom or garage. Or I could go cheap with a Chromecast Audio, but that lacks a number of features I find rather important. After considering my options, I decided I needed an Android media box with Ethernet capability (preferably gigabit speed) and SPDIF out - two things you don't always find on the plethora of media players out there. A solid CPU and generous RAM also seemed like desirable traits, as did full-size USB ports for ease of connectivity. Not that an OTG cable (included) is the worst thing in the world, but I like simplicity whenever possible. It was also very important to have a usable remote control included - yes, I could always run a control app on my phone, or plug in a USB mouse/keyboard, but I wanted ease of use for my family as well, and a real remote seemed like the best way to go. Lastly, Android 5.0 or higher was important, and some of these boxes still use KitKat.





I decided on this YCCTEAM branded MXIII G box which goes for a bit under $75. I flirted with the idea of going Raspberry Pi but that seemed like a rabbit hole from which I might never emerge. No, this was supposed to be a simple project without all the temptation for tweaking that a Pi would bring. I wanted a pre-rooted device that would be relatively easy to get going, and low maintenance to keep running long term. This little device seemed like just the thing. It ticks all the boxes from a hardware perspective and seems to have a good reputation as well - 89 Amazon reviews resulting in a 4 star ranking.




The MXIII box looks to have been around for a while in one form or another, and you'll find many variations out there at different prices. I spent a little more to get the 2GB RAM/16GB storage version with the fast S812 quad-core processor and octa-core GPU - you definitely want to keep things feeling responsive in a device like this, lest it start feeling slow compared to your phone. There are models available with even greater specs but this seemed plenty for my needs. The main "upgrade" I see is the S905 chip which isn't necessarily a big improvement anyway http://www.cnx-software.com/2016/01/29/amlogic-s905-vs-s812-benchmarks-comparison/, so I don't feel like I'm missing much.




I believe the YCCTEAM branding mainly accounts for the pre-installed software package - you can get the same hardware with different branding and it won't be configured the same way out of the box. I've had some poor experiences with other Android boxes as well as tweaked Apple TVs, so I definitely wanted to avoid a repeat. The YCCTEAM box is loaded with popular software, all preconfigured for you, and it ends up working nicely for general use.

For my intended purposes though, the thing unfortunately doesn't work as well as I had hoped. It actually DOES run Roon, and I had no problem streaming from my server which lives on the other side of the house. However the experience is simply not ideal. Problem number one: the included remote (which is actually pretty decent in general) doesn't really work for scrolling through my Roon library. I see the albums listed and can use the virtual mouse option on the remote to select anything I need.... but only on the initial startup screen. It won't let me easily scroll to the next page of albums. I have to grab the little horizontal scroll bar using the virtual mouse, which is nowhere near ideal considering my library has over 6,000 albums. The end result? The whole thing is pretty much unusable. I can load Roon Remote on a phone or tablet and use that to control playback, or I can plug in a wireless USB mouse and keyboard, but none of that is consistent with my goals for this system. I really wish I could scroll using the left/right buttons on the remote as that would be simple and effective - but nope, it doesn't work.




Problem number two: this device resamples everything to 48kHz for the optical output. I was hoping this would not be the case, because I've encountered it before. It seems to me a simple passthrough of the stream would be the logical choice, but for whatever reason that wasn't done here. So I can play anything from CD quality 44.1kHz to high-res material and it all ends up as 48kHz over Toslink. I probably don't have to tell you that manipulation of the sample rate - especially by a lower grade, non-audio-specific device, is generally unwelcome, unless we're talking about a dedicated, high quality upsampling DAC.

I suppose it's only fair to point out that many other devices have the same problem - Google's Chromecast 2 has this issue, as well as the Apple TV 2, 3, and 4.

Still, I don't like it. Running everything through my little Audinst DX-1 DAC via optical connection, there's a noticeable degradation in sound quality taking place. Even compared to a Blu-ray player used as transport - and in this case I'm just talking basic Sony player, nothing "audiophile" caliber - the Android box takes a back seat in SQ. I typically find computer audio to be superior in most cases but this time the disc spinner wins. Some DACs seem less impacted than others - my Anedio D2 for example seems to make the most of the lower quality MXIII signal, resulting in less difference compared to the Blu-ray player. Still, it's not a great result.

To be realistic, the MXIII-G is a budget device with a wall-wart power supply, so perhaps there is more to the equation than just the resampling aspect. I also realize this sample rate was likely chosen due to being more commonly used for video. This may very well be a case of my expectations and needs just not lining up with the intended focus of the device. Unfortunately I don't have any HDMI-equipped DACs (like the NAD M51 for example) that list incoming sample rate, so I don't know if this same thing is happening over HDMI.

As a last ditch attempt to salvage this thing for my intended use, I tried connecting the DAC to a USB port, hoping for bit-perfect output. I tried all the usual Apps like Onkyo HF Player, USB Audio Player Pro, and HibyMusic, with only moderate success. The players all immediately recognized the DAC - unfortunately things got weird from there. I was sometimes able to play a song or two without issue, but more often than not there was random audible artifacts, along with frequent disconnects. The Audinst DAC works well with several Android and iOS devices I own, so I can't blame this connectivity issue on the DAC either. Ultimately it just seems that the YCCTEAM box is not cut out for my type of use.

Aside from that, it actually works well for other needs. I ran Kodi (which handily comes preconfigured), Emby, and Plex for movies, and all worked perfectly. I used Google's Gallery to scroll through high-megapixel photos at a rapid pace, with the same snappy feeling I would expect from a modern higher-end phone. I played all sorts of games ranging from emulators to demanding modern titles, and all worked nicely with very smooth graphics - with the caveat that any title relying on accelerometer controls won't translate well to this format. I don't have a 4K display yet - I'm waiting for 4K OLED to come down in price - but it's nice to know I can play 4K material when the time comes. I believe it's limited to 30fps or 24fps rather than 60, but not having a 4K display myself means I don't really know how important that is.

Overall this seems like a very useful media box for what I'll call "normal" tasks. It just isn't equipped for audiophile needs, or at least not within the parameters I set for it. When I add a Logitech K400 Plus wireless keyboard/trackpad to solve the Roon scrolling issue, and adjust my expectations for sound quality, this does the job well enough for casual use. I like it enough for other reasons that I think it will have a long term home in my spare room. But the search for a simple, affordable, easy to recommend Roon solution continues.

I settled on a 2.5 star rating: 1 star for running roon or just as a streaming audio device in general, and 4 stars as a media box for movies and games. The average there is 2.5.

 
 
Not too long ago, USB audio was considered a joke by most "serious" audiophiles. And to some degree they were right - most early USB capable DACs had very poor implementations, which meant computer audio prioritized convenience over sound quality. Think Spotify which is great for music discovery or background entertainment but not really suitable for critical listening.
 
Fast forward a few years. The USB inputs on a lot of DACs began improving to the point of competing with, and sometimes managing to outperform, their SPDIF counterparts. Asynchronous chipsets became widespread and brought lower jitter along with 24/192 capabilities. Around this time we also saw the proliferation of dedicated audiophile playback software. Computer audio had hit the mainstream, keeping in mind that this is still a niche hobby and nothing will ever really be "mainstream" in the true sense of the word. Regardless, USB was no longer a pariah input, and rare was the DAC that didn't have at least fairly decent USB capabilities.  
 
Then came the rise of the DDC, or digital-to-digital converter. The point being that USB audio was progressing at a rate far quicker than DAC chips, power supplies, or analog output stages, all of which have been fairly mature for many years. A good DDC allowed one to raise the level of their DAC without throwing the whole thing out and starting over. While solid USB implementations were common, it was still rare and expensive to find devices with true reference-quality USB solutions on board, with attention paid to the tiniest details. 
 
I had a great time with DDCs in general. The Stello U3 was a solid performer for a while, beating all competition until the revolutionary Audiophilleo 1 with PurePower took up residence in my main system. That duo was superb - even very expensive DACs from EMM Labs and Esoteric showed improvement with the AP combo in play, and no CD spinner I could find was able to match it, regardless of price. 
 
Audiophilleo

 
Somewhere after the DDC craze hit its peak, something new crept its way in. USB filters, AKA regenerators or "decrapifiers". Take your pick. Notable examples include the Audioquest Jitterbug, the Uptone Regen, and the Wyred 4 Sound Recovery, among many others. These guys have similar goals as DDCs but with a different means to achieve it, and are often different from one example to the next... and their relatively low prices have really helped them take off. It remains to be seen how much this category will grow before being supplanted by something else.
 
Speaking of which, allow me to ramble for a moment.
 
This market is, like any other, prone to trends. The stuff people rave about today as their "end game" equipment is often gone from the system a few months down the line, replaced by the latest and greatest gizmo. We'd like to think this is due to advances in technology but if we're honest, a lot of it seems marketing driven. A "revolutionary" product today is old news tomorrow, superseded by newer and supposedly more refined versions. Between that, and the desire many people have to put that hot new product in their sig or profile, we end up with a steady churn of gear coming and going, each one supposedly more impressive than the last. I have mixed feelings about this state of affairs, but that's not really what this post is about. I just had to give you a feel for where I'm coming from before we went any further. 
 
Anyway, as I said, the Audiophilleo combo served me well for several years. It was very highly regarded at first, and still is in many circles, but as time went on I saw more and more forum discussion about how this or that DDC was superior. In my view the Audiophilleo had become an easy target, much like an HD800 which just begs for a comparison with every new flagship headphone release. Newer and potentially more obscure is always better in the eyes of some people. Which is fine - I don't care what others like or don't like, but for me the AP1/PurePower remained a reference component, even when faced with some tough competition like the Empirical Offramp 5 and Bel Canto RefLink. 
 
Meanwhile, at least on HeadFi, things progressed until general consensus said I could spend a few hundred dollars on one of several different DDCs and get vastly better results than the $1400+ Audiophilleo setup. Still very pleased with my reference, I figured it was time to investigate these things for myself. So I grabbed a Gustard U12, a few variations of the Breeze Audio device, a Melodious MX-U8, and a Yellowtec PUC2 Lite, hoping I could find this supposedly easy improvement. 
 
Long story short - I did not find any of these on the same level as the AP1/PP. After a thorough and frankly not very enjoyable period of testing, using everything from a modest Yulong D200 to expensive Esoteric D-07x and Calyx Femto DACs... I just didn't hear it. The AP combo was more open, more detailed, and generally more lifelike than any of the newcomers. I'll admit the Yellowtec is fairly nice for the price - better than my old Stello U3, and probably on par with my more expensive Resonessence Concero HD (which doubles as a killer DDC). And the other models from Gustard etc are nicely built for the cost. But as far as finding a new reference.... it just didn't happen for me. No offense to anyone who feels differently, but I was at the point of giving up on all this talk of major advances in DDCs, being happy to stick with my AP setup indefinitely. 
 
At that point someone I trust recommended a new device called the Singxer SU-1. I had never heard of it. Based on my initial reading, it looked like the brand hangs their hat on the latest XMOS chipset which is vastly improved from the previous gen in terms of processing power. The SU-1 was not quite released yet, but its little brother the F-1 had just come out and was causing quite a stir. So, without high hopes, I figured I would give this DDC thing one last try before moving on. And I'm glad I did.
 
The SU-1 arrived several weeks later. I got an early unit and it sounds like the company is having trouble keeping up with demand, or at least they were for a moment there. The SU-1 has a lot in common with the Melodious MX-U8 - both are roughly the same size and well built if somewhat industrial in appearance. I actually suspect the two were made by the same people (can't prove it though). As much as I like the Audiophilleo concept, I have to admit these DDCs with the more traditional form factor are much simpler to integrate into my audio system. The Audiophilleo eliminates and extra cable with its direct connect design but then adds several more cables to link up with the PurePower, so it still ends up being something of a mess. Meanwhile the Singxer sits neatly on my rack without drawing attention or complicating things, which I appreciate.
 
 
 
Design
Front panel is simple - just LEDs for power, signal, and DSD, and that's it. Nothing fancy. Around back is another story though.... this little box has extensive connectivity. There's a standard IEC power input with a switch that you'll want to leave on all the time for best results. There's the necessary USB input, and then a whole bunch of other stuff - likely more than most folks will need. We get SPDIF outputs in both coaxial and BNC formats. We also get an AES/EBU output - which is nice, as I feel this format has potential. Many DACs have this type of input yet not many transports or players seem to use it any longer. 
 


Then there's an HDMI shaped output labelled I2S - I haven't used it much myself, but the factory says it works with DACs from PS Audio, Gustard, Audio GD, and Wyred 4 Sound, among others. I2S outputs have been around for a while and taken many different formats for transmission, so it's nice to see things move toward semi-standardization. I say "semi" because there remain a minor few differences between the inputs on those brands. Singxer provides options via internal jumpers on their smaller F-1 product, in order to feed the expected signal to each brand of DAC. I didn't see those on the SU-1 board and wondered if that feature was left out for some reason, until I happened to flip the device upside down for some reason.... there, mounted on bottom of the enclosure, are externally adjustable DIP switches, making the SU-1 that much more user friendly. I briefly tried mine (with the default DIP settings) on a friend's PS Audio DirectStream and it worked fine. Whether or not the I2S format has sonic merit over the alternatives is another matter but I'm glad to have the option. Lastly, there's a "Word Clock" output using BNC format - I can't find any info about it anywhere (Singxer is not big on documentation at this point) so I'll just ignore it for now.
 
 

 
Inside, the SU-1 can be broken down into two sections. First, the linear power supply with a shielded Talema transformer and multi-stage LDO voltage regulation. This PSU sits on its own PCB separate from the rest of the device, which is smart design in my book. The Gustard and Breeze Audio units had zero separation. The Melodious at least had the transformer on a different PCB but not the rest of the power components. 
 
 

 
Singxer's remaining board is a 4-layer PCB with lots of good things to offer. A pair of Crystek CCHD-575 "femto" clocks handle timing, while two ISO7641 digital isolators provide galvanic isolation to keep noise separated. A custom Xilinx FPGA works its magic doing who-knows-what to help the signal stay clean and uncompromised. Honestly I don't really care to endlessly discuss all the FPGA ins and outs (ahem - Chord Hugo) as long as the thing does its job and sounds great.
 
   
The Latest XMOS Chip
 
Galvanic Isolation
 
"Femto" Clocks

 
Now, enough tech stuff. How well does this thing work? Does it improve upon the better options I've heard from Audiophilleo and Empirical and Bel Canto, all of which happen to be on the more expensive side compared to this new batch of supposed giant killers? 
 
 
The Sound
The answer is yes - surprisingly, this $399 device actually delivers what so many before had failed. Compared to my AP1/PP, the SU-1 brings improved spatial cues, superior micro-detail, and a slightly more "black" background, all while sounding more natural in the high frequency range. I wound't call it a night and day difference but with the right system, doing critical listening with excellent recordings, it's large enough to notice on a consistent basis. 
 
I didn't hear any downsides either. The Empirical Offramp 5 was very good but consistently seemed darker than the AP1/PP, to the point where it didn't work for my tastes unless I built a system specifically around that signature. The Singxer imparts no flavoring of its own, instead letting the DAC stretch its legs to the best of its ability without being influenced. I REALLY like this thing. 
 
The Singxer brought at least a small improvement to almost every DAC I tried. Interestingly, there was no real correlation between price and potential performance improvement. The Yulong D200 at $699 shows a very modest gain, while my Calyx Femto which sells for roughly 10 times as much gives a comparatively massive improvement - it's almost like listening to a whole new DAC. The obvious answer is that an expensive DAC should be more resolving and thus better able to showcase a superior source. But I'm not convinced that's all there is to it... looking at the USB design on the Calyx as well as my Esoteric D-07x ($5K) tells me even higher end devices don't always have the best USB implementations. The little D200 has a nice Amanero USB board running off internal linear power, and it works well enough to where the Singxer can't do a whole lot better - it's already bumping up against the limits of the DAC. My reference DAC is the new Resonessence Labs Invicta Mirus Pro which arguably showed no improvement at all, while my next best performer, the B.M.C. UltraDAC, showed a small but reasonably worthwhile gain - the sound was certainly different if not completely better. Meanwhile, huge, almost transformative gains took place in Simaudio's 430HAD, which is technically a headphone amp with a surprisingly nice add-on DAC. I like it well enough using the built-in USB input but it really opens up with the SU-1 in place. The Cayin iDAC-6 shows a fairly small difference while the Anedio D2 sounds absolutely killer with the Singxer, FAR better than the stock USB input. And the Unique Melody Platform Pure 6 was completely transformed into a world class system despite all its quirks - over standard USB it just doesn't come close to this level. I won't go on and on about each individual DAC other than to say A) the results were often surprising, and B) $399 was definitely worth it in the majority of cases.
 
B.M.C. UltraDAC
 
Unique Melody Platform Pure 6 System
 

Invicta Mirus Pro, Cayin HA-1A MK2, HE-1000
 

Simaudio 430HAD, Enigmacoustics Dharma
 

Anedio D2, Pass Labs HPA-1, HA-1A MK2, HD800, K812
 

Cayin iDAC-6, iHA-6, HA-1A MK2
 

 
Overall, I was highly impressed with my results using this thing, but I figured perhaps there might be other options to explore as well, just to give a more complete picture of where things stand regardless of price. So I rounded up a few heavy hitters in the segments for comparisons - the Berkeley Alpha USB, Audiobyte Hydra Z, and a Soulution 590. Does throwing more money around make for an easy solution (no pun intended)?
 
Long story short, I think the Singxer is very competitive even in this expensive field. The Soulution is pretty respectable, but still inferior to my Audiophilleo setup, and thus overpriced for what it is. The Hydra Z is probably on par with the AP1/PP which is quite impressive to my ears - and I didn't even have their ZPM power supply which may have brought it up to another level. So I can definitely recommend the Hydra Z for the price they ask. But I was most impressed with the Berkeley - talk about a sweet sounding DDC! The Berkeley is everything one could want in a device like this, except.... it sells for nearly $2K and is highly focused on that AES/EBU output which not all DACs can accept. Still, I think most ears would concur with mine in thinking the Alpha is a stunning performer even at its relatively high price.
 
The Singxer, to my ears, is very competitive with the Alpha USB. I listened back and forth for quite some time, to the point where it became downright tedious, and still don't feel confident in judging which one is best. The conclusion I came to? If there is a difference, it's very small, and certainly not worth the extra cash you'll spend to get it. This is kind of a big deal since the Berkeley has been widely accepted as top dog for some time now. To get a similar, possibly identical level of performance for so much less money is almost hard to believe - but that's the way I hear it.
 
 
Downsides?
So far, so good right? The Singxer SU-1 is a killer value with superb sound quality. Should everyone rush to place their order? Not quite.  As with all other DDCs, it really depends on your DAC. The main problem as I see it is with the SPDIF implementation. All the fancy digital to digital conversion in the world won't do you much good when passed through a CS8416 DIR with its high intrinsic jitter. Which means some DACs just aren't good candidates for this type of improvement. Also, some DACs (the Anedio D2 for example) essentially have an internal DDC where all signals end up taking the same path, while others pass USB data directly to the DAC. Meaning potentially a shorter and more pure signal path compared to even the finest DDC. Do you know what your DAC does and what that translates to in terms of upgrade potential with a DDC? If not, you might want to find out before making a purchase. Granted a $399 device like the SU-1 is a smaller risk than a nearly $2K Alpha USB, but it's still good to be well informed before spending any amount of money.
 
We also have to consider your source - is the SU-1 being fed by a basic laptop which was never designed for high-end audio playback? If so, improvements can be substantial. If the source is a dedicated music device from a brand like Aurender or SOtM, there's a chance that direct USB connection might be the better choice, again depending on the DAC. Or you may just find the difference small enough not to bother with. It definitely requires some thought.
 
There's also the matter of DSD and really-high-res PCM. Most modern DACs can accept up to 384kHz PCM over USB. Yet they top out at 192kHz over SPDIF or AES/EBU - that's just a general limitation of those transmission formats. Do you have a small collection of DXD music? Too bad, can't play it over the Singxer. Same deal with DSD - most DACs accept DSD128 or higher over USB, while the Singxer can only support DSD64 - and even then it requires a DAC willing to accept DoP over SPDIF - Some do, some don't. I'm certainly not a format nut and don't care about missing DSD512 capabilities but I do have a decent handful of DSD128 albums which I can't play through the SU-1. So this is something to consider. Note that the I2S output has no such limitations, on the off chance you are using one of the few DACs which handles that type of signal. When I paired it with a DirectStream DAC it worked flawlessly, and would thus be my default choice unless I could find some SQ-related reason not to go that route.
 
Lastly, I'd suggest keeping all options in mind. For example, you might see better results using a USB device like the W4S Recovery or Uptone Regen rather than focusing on USB to SPDIF converters. I admit I'm not the target market USB decrapifiers since I usually run from a quality dedicated server or streamer. But I've done my share of comparisons and came out with the B.M.C. PureUSB1 being my favorite. The $390 PureUSB "restores, reshapes, and stabilizes" the signal prior to entering your DAC, and does an especially noteworthy job at turning mediocre computer sources into excellent transports. I found that certain DACs responded better to the PureUSB1 when the Singxer made smaller gains - B.M.C.'s own UltraDAC was preferable with the PureUSB1, as was the Cayin iDAC-6. My solution was to combine them, going from USB out to the PureUSB1, into the Singxer, then coaxial or AES/EBU out to my DAC. I don't think I necessarily heard much of a cumulative advantage, but neither was there any drawback compared to individual use, and this saved me the trouble of figuring out which one was best utilized in a given situation. Which one do I ultimately recommend? That's impossible to say without knowing your setup, and ultimately you could pick up both for less than half the price of a Soulution 590 or Berkeley Alpha USB.
 

B.M.C. PureUSB1 Active USB Regen Cable (all others are Cabledyne Silver Reference)
 

 
Still, if it sounds like I'm trying to talk you out of considering the killer device I just praised a few paragraphs above.... I'm not. I just want you to make an informed decision rather than get caught up in the hype of a shiny new toy. Yes, the Singxer SU-1 is potentially an excellent upgrade for some of you. In other cases, something like the B.M.C. PureUSB1 is the better upgrade. And for some, both of those devices together is an ideal combo. But let's not overlook the many others who just need to get better headphones, a different amp, etc. I regard DDCs and USB regen devices as being more efficacious than cable upgrades, but not nearly as important as having the right DAC or amp or headphones. Perhaps the best analogy would be power conditioners - in some cases they work wonders, while other times they don't do a thing in terms of audible enjoyment. The problem I see is when forum dwellers and yes, even reviewers (professional or otherwise) throw around absolutes - "buy this power conditioner and it will DEFINITELY improve your system. If you don't hear it, something else is amiss with your gear or your ears." That's not the right approach, and the same applies for DDC and USB regen devices as well. There are just so many factors at play that it's impossible to predict how much of an impact these things might have on your system.
 
Conclusion
In the end, the Singxer SU-1 stands tall among its peers, being the first DDC I found to clearly improve on my prior reference. That's a bold move for a $399 device, and a big win for those of us who enjoy stellar performance at a reasonable price. Let's put it another way - a less than scrupulous audio company could very easily pull a "Lexicon BD-30" using the Singxer SU-1 inside a fancy case. Add in some slick marketing and they could sell it for thousands of dollars.... and people would likely be happy with what they get for that money. Seriously, unless someone figured out the origin, there would be no indication of the thing being a $399 device in fancy clothing - it's that good.
 
We'll have to see about other upcoming devices using the same xCORE-200 series platform from XMOS. I suspect that despite the horsepower improvement of that chip, the results here still rely heavily on proprietary FPGA programming, those top-notch Crystek clocks, and good old fashioned design excellence. I don't necessarily expect a repeat performance from every newcomer, but we'll see. In the meantime, I'm off to listen to music for a few days without worrying about gear, in order to make up for all the tedious switching involved in this review. I think I've earned it.

Custom In-Ear monitors. I love 'em. There's nothing quite like the experience of a custom-molded, perfect-fitting IEM which practically melts into your ears. I can listen for hours without fatigue, and on the rare occasion where I use a universal model, I'm inevitably uncomfortable within a half hour or less. Then I switch back to a good CIEM and all is right with the world once more. I realize that aspect is different for everyone - some people get along just fine with universals, so it's definitely an individual preference.
 
I recall the early days of custom monitors. Back when they were primarily considered tools for musicians and their supporting staff of engineers etc. You think custom IEMs are costly now? Roughly a decade ago, I paid nearly $1,000 for the Ultimate Ears UE-10 Pro, a triple driver model which at the time sounded fantastic but is absolutely nothing special by today's standards. Nowadays that level of performance can easily be had for quite a bit less, from one of the many, many brands making custom monitors. Back then we had UE, Sensaphonics, and Westone as the main players, with a few lesser known brands floating about in certain regions. Today there are dozens and dozens of CIEM companies which in my mind is a great thing: more competition, more options, and a better chance at having a local firm - you may even be able to visit in person. The only real downside is keeping track of them all.
 

 

 
One of those many brands is a company called Jomo Audio. Based in Singapore, Jomo is the brainchild of Joseph Mou (get it? Jo Mo?) who has worked in the broadcast industry for years. While handling equipment installation and related tasks for TV and radio stations, Joseph found himself infatuated with IEMs. It started with universal models from the usual suspects like Shure, but the engineer nature proved too strong. One thing led to another, and after much research (and money spent) Joseph had "made" his own custom IEMs - though it would probably be more accurate to say he had reshelled an existing universal model. But he wouldn't stop there.
 
This is where Joseph joins the ranks of John Moulton (Noble Audio) and Piotr Granicki (Custom Art) - passionate enthusiasts who couldn't leave well enough alone and just had to make their own custom IEM designs from scratch. He became active in the massive Home-Made IEMs thread as well as other threads on local forums. Things progressed until mid 2015 saw the launch of Jomo Audio, primarily serving his home region but eventually branching out across the globe. 
 
Now, I've never personally traveled to Singapore, but word on the street says there's a plethora of audio shops, in which one can demo practically any headphone in existence. I specifically asked Joseph about rival brands and he told me he could drive less than 30 minutes to find Ultimate Ears, Westone, JH Audio, or any number of other brands. This is a blessing and a curse - it helps him know where his designs stand in relation to established firms, but also makes life hard for a startup due to the extremely competitive nature of the local market. 
 
One solution is to sell at rock bottom prices. Become a derivative brand, or sell reverse engineered UE and Westone designs for dirt cheap. I've seen those sorts of operations come and go on Taobao and other markets. It might actually be a profitable endeavor but isn't likely to satisfy someone who has a passion for designing their own stuff. Joseph figures the way to stand out is to offer excellent craftsmanship, beyond what most others are capable of. That, combined with excellent customer service and a robust line of great sounding IEMs, should leave a trail of satisfied customers large enough to attract some buzz. So, while Jomo's prices aren't the lowest you'll find, they certainly aren't the highest either, and the company aims to give an "experience" on par with the best out there without charging top dollar. That's the theory, let's see how well it works.
 
 
The Lineup
Jomo offers a range of products starting from a single-driver design all the way to the upcoming Samba 8-driver model. Under review today is the current flagship of sorts, the Jomo 6R - there's also a non-R Jomo 6 using different drivers and different tuning, with a slightly lower price. Joseph tells me the 6R design was 8 months in the making, inspired by pleas from local musicians and audiophiles wanting a clear, highly resolving sound which could be easily driven even from a low power source. The 6R starts at $1399 for the standard configuration and moves up to $1649 for the "deluxe design" package which opens up all sorts of possibilities for exotic looks. Keep in mind those prices are in Singapore dollars, which at the moment translates to $1043 to $1229 USD. So, roughly in line with what I've come to expect as the general price-range for upper-level custom IEMs, though I'd say that average is on the rise thanks to some other brands.
 

 
The 6R is at present the sole member of Jomo's "Reference" line. The stated goal is to give a flat response suitable for "reference monitoring" - whether that term appeals to working professionals in the music industry or just to enthusiasts unwinding after a long day is open for debate. Jomo claims the design delivers "crisp sound" so the listener "will not miss a single note". Slick marketing is not really Jomo's strength but I'd say this is an accurate description of the 6R experience. 
 
 
Design
The design uses 6 balanced armature drivers, likely from Knowles Acoustic since Joseph mentioned their name during our discussion (it helps that they remain the largest and most common provider of BA drivers, so the odds are in my favor). 6-driver designs are pretty much ubiquitous these days, often but not always positioned as the flagship in a brand's fleet. Yet there are many different ways to do a 6-driver IEM. Jomo's design uses a single dual-high driver, a pair of individual midrange units, and a vented double-low driver for bass, with frequencies routed via 3-way crossover. The tip features what they call an "advance sound horn outlet design". This can be seen in my pictures - it's hard to explain but easy to understand just by looking. This is a classic horn design as used in many speakers, as well as some models from Westone, Rhines, and Vision Ears. The main goal is to improve high frequency response allowing better clarity and detail to come through. A nice side benefit is the resistance to clogged sound tubes.... earwax has a far smaller chance of getting wedged in the tube itself, since there's a buffer of sorts standing in the way. Worth noting: really small ear canals will be unsuitable for the horn tips, and in that case a more typical flush design will be used. I won't speculate as to how that might impact the sound, since my large ears had no problem accommodating the horn design.
 
 

 
Jomo rates the 6R as having a 20 ohm nominal impedance. As always, that doesn't paint the whole picture. In this case the curve is fairly benign, mostly flat with a small peak in the 2.5kHz range and then steadily climbing until it hits roughly 40 ohms at 20kHz. Driving the 6R with a high output impedance will impact the sound to some degree but nowhere near as drastic as the Shure SE846, Ultimate Ears UE900, or NuForce Primo 8, to name just a few designs with wild impedance swings. 
 
With a sensitivity of 126dB, plus the relatively easy to work with impedance curve, the Jomo 6R definitely meets its goal of being easy to drive. It's a resolving IEM that does benefit from a really clean source, but pleasing results can be achieved from simple things like the iPhone or a Sansa Clip. Hiss can be a problem with some DAPs - not to the point of being completely unlistenable, but I do question whether the increased general fidelity is worth the trouble over just using my smartphone. At home, it's the same deal with desktop amps, many of which are unsuitable to the task due to high gain and general noise with sensitive IEM use. My MacBook Pro and Surface Pro 3 both gave very enjoyable results straight from their headphone jacks, to the point where I would rather use them alone unless I happened to have one of the few devices handy which could give a similarly clean, quiet performance. Seriously, as much as we tend to look down on more pedestrian sources and brag about our expensive gear, the Jomo 6R really doesn't need much to perform very well. I'll discuss this more soon enough.
 
 
Exterior
As you can see from the pictures here, my particular 6R is pretty extravagantly designed. I just let Joseph go wild and make whatever he wanted, and the result is described as a "ribbon faceplate with starry black shell". Build quality is very high if not quite to the level of a Wizard Design product from Noble Audio. You can see other designs HERE - Jomo has plenty of interesting builds on display. 
 
 

 
One area where I'd say they still lag behind is the ordering system. While Noble, JH Audio, and Unique Melody have websites giving a clear breakdown of available options, the Jomo site is fairly simplistic. I get the feeling you'd end up describing what you want and hoping for the best, or perhaps sending a picture of an existing CIEM you found online to see if Jomo can do the same for you. Which is probably fine, but I would expect the website to improve as Jomo grows. 
 
 
Sound
Let's talk about the most important aspect of any IEM - the sound. The 6R is described as being exceedingly neutral, and I do agree with that statement in general. Problem is, everyone has their own take on what "neutral" really means. Obviously the goal is a flat presentation with no obvious peaks or valleys, but even within that framework there's still room for variation. Is the HD800 neutral? Some say yes, while others say it's too bright. The Etymotic ER-4S? The Stax SR-009? Same deal in both cases. Personally the most neutral sounding "headphone" I've used is the Stax SR-4070, which I feel is even more uncolored than their flagship SR-009. It's not always the most pleasing choice for regular listening but Stax designed it as a "monitor" earspeaker and I have to admit they achieved that goal nicely. 
 
The Jomo 6R sounds remarkably similar to what I hear playing the SR-4070 through my hot-rodded KGSSHV. Both have a flat, neutral response with excellent detail retrieval. Bass on the 6R is very well controlled, possibly a touch more present than on the Stax model though not by a huge amount. Both of them lack bass bloom meaning they do what the recording calls for, even when it ends up sounding less weighty than we might like. I'd say the HD800 low end comparison is also apt - but only when the Sennheiser is properly driven - being fairly similar in quantity and quality. At times the 6R seems more prominent in terms of bass attack, though other times it is right there with the Stax and Senn. I speculate this may be related to the inherent differences between full-sized electrostats and in-the-ear designs using balanced-armature drivers. The somewhat lean bass impact does take some getting used to at times - when switching from most other headphones or IEMs, these will seem overly thin at first, and over time will gradually begin to sound "right" as my brain acclimates to the lack of bass boost. I suspect there are some people who will never quite adjust to this type of sound. For them, the regular Jomo 6 is probably a better option.
 
Midrange on the 6R is again very similar to the 4070 - both are dry, well controlled, and very "matter of fact". The Jomo 6R lacks the stunning fluidity of a Noble K10 or Westone ES5, just as the 4070 lacks the midrange beauty of the SR-007 models... but I think that's kind of the point. There's a sense of uncolored, almost brutal accuracy that can be off putting on poor recordings yet magnificent when playing reference-caliber material. Both models are ruthlessly unforgiving, especially with vocalists. I've had several instances where the singer on a live album sounded just fine during general listening, but critical monitoring with the Jomo 6R exposed more than a few mistakes. Again, this seems to be deliberate, with the point being accuracy in monitoring rather than pure listening enjoyment.
 
Highs on the 6R are exceedingly neutral. There's plenty of extension without the sense of artificial sparkle added by certain IEMs. As a percussionist, my usual test material involves lots of cymbals - often times they end up sounding a bit glassy, or grainy and harsh, or muffled and dead.... there are plenty of ways to do it wrong but the 6R avoids those pitfalls. The JH13 (FreqPhase but not V2) is far more energetic and sparkly which initially sounds great but is probably more "hyper-real" than it should be. It's the equivalent of a bass boost where I might enjoy it while at the same time being cognizant that it is in fact a form of coloration. So there's no added excitement up there, but things can still get bright in a hurry if that's what's in the mix. Many albums out there have all sorts of grit and grain and the Jomo won't hide any of that - if the recording is poorly done the 6R has no qualms about showing it. 
 
I really have very little to complain about with regards to high frequency reproduction. If anything I'd say it still lacks the world class realism of the Stax electrostats - that again seems to be a limitation of the different formats. It's not as fast and can't maintain the decay of a big ride cymbal as well as the Stax or even the HD800. But as far as IEMs go, the Jomo 6R is right up there with the best I've heard. Again, it's somewhat hard to explain this issue but anyone who owns upper-level IEMs as well as full size cans should know what I'm talking about. It's not necessarily about preference either.... I might find the IEM presentation more appealing in some ways, while the big cans are more convincing in other aspects. Either way, it's clear they are different and difficult to directly compare.
 
Soundstage on the 6R is somewhat small which may come as a surprise to some readers. The HD800 has a fairly similar sound signature but manages a huge, three dimensional presentation. So what's wrong with the Jomo? Nothing really, as it falls in line with the Stax 4070 which also has a fairly compressed, "direct" sound to it. Imaging on both models is tight and focused beyond that of most competitors, but there's just not a huge sense of space involved. I suspect the "peaky" areas where the HD800 gets more exaggerated than the 4070 or 6R accounts for at least part of this difference. That, and the physically angled drivers which play some part in it. Interestingly, this intimate presentation didn't end up bothering me as much as I initially thought it would. Once I got into "monitor" mode, I stopped looking for the usual HiFi experience, and was able to enjoy the presentation for what it is. 
 
Worth noting: I primarily used an Effect Audio Eros 8W cable for my listening, as seen in the pictures here. The stock cable is a fairly typical CIEM cable with the traditional 2-pin connection that we used to call "Westone style" before Westone switched to something different. It comes in a gray color which is not very common - usually we get a choice of boring black or silver which will soon turn green with oxidation. As far as stock cables go, Jomo gives a fine performance, being among the more supple and sturdy stock CIEM cables I've experienced. This isn't a cable review so I won't wax poetically about the improvements caused by the Eros 8W. As usual I feel they are subtle, certainly not "night and day" as some people claim, but definitely present nonetheless. I'll just say the Effect cable upgrade gives me a more transparent experience than the stock cable alone, assuming everything else in the chain is up to par. I don't recommend cable upgrades until way down the line when you've built up the rest of your system, and I'll happily use the 6R with a stock leash under certain circumstances. Yet given the choice I prefer an upgrade like the Eros 8W if I'm doing critical listening on quality gear.
 

 
 

 
Comparisons
The most obvious competition for the Jomo 6R is the Ultimate Ears Reference Monitor, or UERM for short. I was so curious about it that when I saw a used pair for a good price, I snatched them up just for comparison purposes. I then had them reshelled by someone in the industry whose work I trust completely - I'm confident the result is very similar or identical to what I'd get if purchased directly from Ultimate Ears. 
 
I can hear why so many people enjoy the UERM. It's got a lot of the same qualities as the 6R, and generally fits the neutral description above in most ways. The difference? Jomo seems to have beaten UE at their own game. While both models have a very similar frequency response, the presentation of the 6R is superior in several ways. The main thing that gets me is the UERM feels aggressive and therefore fatiguing at times. Mid and possibly upper treble has some mild harshness to it which I don't hear on the Jomo. This was hard to nail down at first, yet fairly obvious after a few albums worth of listening. The Jomo sounds more resolving where the UERM struggles at times to hit a clean leading edge - perhaps the lower driver count has something to do with it? I'm not sure, and I don't like to perpetuate the "driver wars", but that would be one possibility.
 
The other key difference in on the low end, and this one took me even more time to figure out. The UERM and the 6R feel very similar in terms of bass volume relative to the rest of the spectrum. Yet somehow the Jomo has a more convincing sense of impact, despite the bass not really being any louder. After a while I discovered that although the UERM sounds pleasing on its own, in comparison to the 6R it doesn't have the tightest bass performance. Tyll Hertsens nailed it when he said (referring the the UERM): "While the bass level is good, I do find them a little loose sounding and lacking in punch." Bingo. Both models have a very similar presentation at face value but Jomo does it better if we listen closely. Again, is this the higher driver count? Maybe. Worth noting is that Ultimate Ears has a newer model called the "Remastered" Reference Monitor. I haven't heard that one so I don't know how it compares to the 6R.
 
 
Gear Matching
Lastly, let's talk equipment. I mentioned earlier that a simple iPhone or one of the better Android devices can already get excellent performance out of the Jomo 6R. I stand by that statement - I've got dozens of DACs and amps laying around here and I love nice gear as much as the next enthusiast, but I have to admit there's not a huge requirement to get high quality sound out of these CIEMs. I spent a lot of time streaming Tidal lossless on my iPad Air 2 and my Surface Pro 3. Both did a very good job driving the 6R with satisfying authority and a dead silent background. My wife's Asus Zenbook didn't sound nearly as competent due to background noise and hiss, so it's not universal, but with luck you already have at least one device in your home capable of fantastic sound with these things.
 
For DAPs, I had hit or miss results. My go-to is the Questyle QP1R as it usually sounds great with IEMs. It has an ultra-low output impedance and is typically very quiet. But not this time. Even on its lowest gain setting, the QP1R had the 6R hissing like an angry cobra. I've never heard an IEM do so poorly with that particular DAP, and the sonic improvement (chiefly an increased sense of resolution and micro detail) was simply not worth it compared to using an iPhone or quality Andriod device. This was a surprise that I did not see coming, so QP1R owners: consider yourself warned.
 
 

 
 
 
The Acoustic Research M2 did surprisingly well for having a 10 ohm output impedance. It sounded more substantial and effortless than the Questyle had. But on jazz or classical I was distracted by a weird background noise - not hiss, but rather some sort of random click-pop interference type sound. I ran in airplane mode and moved far away from any source of RF noise yet the problem persisted. Perhaps the 6R is simply too sensitive for the powerful amp section in the M2.
 
The original Fiio X5 had similar if slightly less annoying levels of noise, but it is clearly not in the M2's league. I found the upper midrange unrealistic and fatiguing to the point where long term listening was not desirable at all. I'd call this a textbook poor match - I believe the 2nd gen model fixes this issue, thought I don't have one here to test at the moment.
 
The iBasso DX90 had just the faintest bit of background grunge, low enough in volume where it didn't really bother me, and had no problems with hiss. This was a very worthwhile match for a reasonable price. The huge range of volume adjustment is appreciated for dialing in exact levels, and the generally neutral tone made it easy to separate good recordings from bad. In the end this is one DAP which is worth using over an already excellent sounding iDevice or Android, for those looking to move up the chain without spending a fortune.
 
Sometimes you want a more musical approach. The Pono was virtually silent and made a great pairing, its somewhat musical presentation taking a bit of the edge off the 6R's serious character. I also enjoyed Sony's punchy, smooth ZX2, despite the relatively loud hiss it exhibited. It sounds counter-productive but again the pairing of musicality from the DAP and accuracy from the 6R just worked on some level. Same for the Calyx M which had practically zero hiss and gave the 6R a superb low end kick. If only it had a better battery. 
 
 
 

 
HiFiMAN's HM-802 and HM-901S siblings were interesting. The 6R really showed off the value of having a modular amp system. The "standard" amp which shipped in the 802 was a little hissy and a lot uninspiring. Not terrible but definitely not impressive either. Switching to the Minibox Gold amp card which came in the 901S gave excellent results but the hiss was again too much for me - others might find it within acceptable range but I'm more sensitive than most. The 802 plus Minibox was very similar to the Sony ZX2, while the 901S plus Minibox was like an improved Pono experience, though with more hiss. Ultimately my favorite amp card was - surprise - the IEM card. It was nearly silent and had excellent detail retrieval, along with just the right amount of gain. The 901S gave spectacular "monitor" results while the 802 played it warmer and more casual. I enjoyed the 901S more but the 802 definitely has its place. 
 
 

 
As much as I liked the various DAPs, my favorite results came from listening at home on a bigger setup. Again, there aren't a huge number of desktop amps or DAC/amps that pair well with the sensitive Jomo. Beasts like the Violectric V281 and Simaudio 430HAD, normally very quiet with any headphone you throw at them, both had an excess of undesirable noise. The Pass Labs HPA-1 even more so. The Cayin iHA-6 in balanced mode was workable, especially when fed a lower voltage signal to keep levels manageable - a standard 2V signal meant precious little room for dialing in proper volume. 
 
A very music combo I found was my Expo 93 (Examplar modded Oppo unit) feeding a NuForce HA-200 amp via analog outs - no external DAC in the chain. This is a sweet, musical pairing which renders female voices and stringed instruments with a certain magic that is just the ticket for relaxed listening. I wouldn't use this setup for critical monitoring, as it is merely good and not great in that aspect. For late night listening after a long day or work, perhaps with a nice adult beverage in hand, this is a compelling setup. The Jomo 6R is a chameleon which lets the rest of the chain shine through clearly.
 

Expo 93
 
In the end I went back to where I often go with CIEMs - the Anedio D2 and the Questyle CMA800i DAC/amp units. Both have stunning headphone outputs with inky black backgrounds. I've been messing with adding JPLAY to Foobar on my Surface Pro 3 - it really does make a worthwhile difference without changing the interface I'm so accustomed to. JPLAY cleverly installs as an ASIO driver which can then be selected as an output device inside of Foobar. It takes a resolving transducer to showcase the full extent of improvement, and the 6R is up to the task. The CMA800i seemed better initially, until I recalled that the Anedio seems to scale well with USB to SPDIF conversion. So I threw in the new Singxer SU-1 which is at present the bang-for-buck champion of the world as far as I'm concerned. Now the Anedio kept pace and even surpassed the more expensive Questyle in some areas. The combo of JPLAY, Singxer, Anedio, and Jomo 6R is startlingly resolving, and I admit to losing more than one evening meandering through my favorite recordings. The whole system is under $5k (the number I hear thrown around a lot to indicate "affordable" systems) including a top-model Surface Pro 3, power conditioner, nice cables, etc... I've heard waaaay more expensive rigs not live up to the same standard. Excellent recordings on this rig will knock your socks off and poor recordings, well, you probably won't last very long on those tracks before skipping to something else. Which is the same way I describe my Stax rig when using the SR-4070.
 
Singxer SU-8 USB Bridge
 

 
 
If DACs with four-figure price tags aren't your thing, the Grace Designs m9XX is a worthy option. It gives just the slightest amount of hiss, not enough to bother me (and as I said, I'm more sensitive than most in this aspect). The big volume knob is excellent for dialing in perfect volume levels, and the Grace has just the right mix of detail and musicality to make the 6R shine. It doesn't keep up with the Anedio and Questyle units, and for $499 I wouldn't expect it to. 
 
 
 

 
Conclusion
The Jomo 6R is certainly the most neutral IEM I've heard. Which can be a very good thing if one is honest about what they really want. Many claim to want neutrality when in reality I suspect they prefer some minor coloration - a bit of warmth down low, perhaps some midrange bloom, maybe a touch of smoothness in the upper mids and highs. And there's nothing wrong with that. There are many other "mostly neutral" IEMs that I can heartily recommend: the Noble Savant SLA, Unique Melody Miracle, and Lear LCM-5 all come to mind. The first step is figuring out what you're really looking for, and proceeding from there. 
 
For someone sure they want brutally, beautifully neutral sound from a custom IEM, the Jomo 6R is an excellent choice. It handily beats the original Ultimate Ears Reference Monitor by doing the same things but doing them better. It's really quite easy to drive and sounds very respectable from everyday gear like an iPhone, making the 6R very accessible compared to some CIEMs which are more source-demanding. At the same time it does reward quality gear, being among the most revealing ways to listen to differences between DACs or transports. Ultimately the 6R is a unique and very appealing choice which I can easily recommend.

 
 
There simply can't be too many affordable devices on the market. It's not possible. More choice is always a good thing. This assumes, of course, that at least some of these options will be solid performers. But if we think about it, the odds are in our favor when more and more devices hit the street. If we assume an arbitrary number of products - say 50% - will be terrible, with perhaps 30% being decent and the remaining 20% being good... a larger pool of designs to choose from will result in more "good" options standing out from the crowd. Makes sense right?
 
When people say "affordable", they don't always mean the same thing. In some circles "affordable" components are those costing less than $10,000 (give or take a used Honda Civic). So what we might consider a Summit-Fi headphone system would actually cost less than one "affordable" pre-amp or set of speakers. In other situations "affordable" is taken to the extreme, where a Sennheiser HD600 then becomes prohibitively expensive and headphone amps or DACs costing several hundred dollars shouldn't even exist. Most of us probably fall somewhere in between those two, where gear around $200-400 or so can be considered somewhat on the affordable side. 
 
To that end, companies like Audinst are great to have around. For several years now, Audinst has been churning out one solid budget device after another. Nothing world-shattering, just competent, well-done gear offering good sound at a reasonable price. I believe their most pricey offering was the HUD-mx2 at around $250. Not bad for a DAC and headphone amp which could drive most anything decently well, and control volume on a pair of active monitors too. 
 
The latest design from Audinst continues that tradition of quality for a good price, though the quantity of each seems to be creeping upward. Is that a good thing? I suppose it depends on your needs. At $398 direct from Audinst http://audinst.com/en/shop/ the new HUD-DX1 is another all-in-wonder handling DAC duties, headphone amplification, preamp functionality, and even USB to SPDIF as a bonus. So far so similar to the last few models right? The mx2 seemed like a reworked, upgraded version of the mx1, and this new model doesn't stray far from that same concept. A redone enclosure looks and feels a bit more upscale. I got my review unit in black with gold accents, but one could just as easily snag the white and silver model to match their modern Ikea desk.
 
The gold feet are a nice touch:
\
 
 
 
 

 
This time around we get an ESS ES9018K2M DAC chip, being fed by an XMOS-based asynchronous USB input capable of DSD and DXD. If you recall the prior model used a TI PCM1796 DAC with an adaptive-mode USB implementation from chip maker VIA, topping out at 24/96. Audinst now hangs their figurative hat on the JRC Muses8920 opamp - a rather nice choice indeed - where the prior model had a mix of OPA2134, OPA2227, and LME49860 opamps. That means I/V conversion, differential amplifier, and line-out are all handled by the Muses chips. Headphone driver remains the same TPA6120A2 tweaked for 2 ohm output impedance. Max output is 1.5W into 32 ohm loads, and 10Vpp at 600 ohms. Reaching full amplifier potential will require tweaking an internal jumper and running on AC power as opposed to USB. 
 
Aside from those changes (and the driver software, obviously, due to the new USB solution) this is classic Audinst. The enclosure may look a bit different but the ins/outs remain identical. The front panel has the dedicated jacks for 1/4" and 1/8" headphones, switches for headphone or line-out activation as well as USB or optical input. Rear panel has Toslink in and out, USB in, RCA out, and a spot for the power adapter to connect. It's all quite familiar by now. I go back and forth between being disappointed by the lack of innovation, and satisfied by the "If it ain't broke, don't fix it" mentality. After roughly 5 years without any functionality updates, Audinst still has one of the most feature-packed devices out there.... so I guess there's no compelling reason for a change.
 
 

 
 
Internal pics show a largely similar layout to the prior models. As mentioned, we do get the new ESS/XMOS combo which requires some accommodation in the surrounding design. I also notice there's no longer a dedicated chip for receiving digital inputs - the Sabre chip itself has onboard DIR capabilities so Audinst must be taking full advantage of that feature. Aside from that, and the Muses opamps being utilized, the remainder of the board looks 95% unchanged. 
 
 
Total of four Muses8920 chips (only two are socketed)

 
 
TPA6120A2 headphone driver:

 
 
 
XMOS USB input:

 
 
 
ES9018K2M DAC chip:

 
 
 
 

 
 
LISTENING
I'm very familiar with the prior HUD-mx2. It was an evolution of the mx1 with which I was also quite well acquainted. The DX1 comes along using a very similar design so I naturally assume the sound will follow suite. And I find myself being wrong, as this is something of a departure from the earlier Audinst house sound. Not that I'm complaining, mind you. Prior gear was mainly neutral, as transparent as could be expected for a budget all-in-one. It worked well with a variety of headphones and in exchange could be perceived as being just a tad boring in some instances. The new DX1 is far more lively - robust bass impact, thick, rich, weighty mids, and top-end sparkle like never before. I wouldn't necessarily call it an overly colored presentation, but in comparison the older mx2 sounds downright vanilla. Is this an insult? Not necessarily. Some people love vanilla. 
 
 

 
I noticed the change right away when listening with the Fostex TH-X00. While the mx2 did a respectable, even-handed job with these excellent "sealed" headphones, the DX1 turned the excitement up to 11. Bold, impactful bass was the order of the day. Vocals more engaging. Cymbals more splashy and extended. I rather enjoyed it though I can see how long term listening might favor the mx2 in this particular instance... depending on your musical preferences, the TH-X00 might be exciting enough already without the extra help. DX1 is excellent for shorter stints though, and its liveliness is exactly what I want for artists such as Infected Mushroom, Lotic, Floating Points, Arca, etc. 
 
The AKG K812, however, sounds quite a bit more enjoyable on the DX1, across all genres. The mx2 renders a somewhat flat presentation, lacking a bit of passion. DX1 drives it with attitude. The K812 gets less respect than HD800 as a proper flagship but I find it on par and in some ways superior to Sennheiser's offering - this being one of those times. The HD800 needs substantial amplification to bring out its best while K812 can sound very good from a portable amp, integrated DAC/amp unit, or even a DAP. Driving my HD800 from the DX1 is mediocre at best (though still better than the mx2) but the DX1 plus K812 combo is very respectable. I particularly like how dynamic it sounds with Holst and Bassie - two selections which don't sound the least bit convincing without a proper sense of scale. 
 
I tend to run off USB power most of the time. It's nice to have flexibility to add more juice via AC power brick, but I find it makes just a small contribution to the overall sonic picture. Specifically when driving planar magnetic headphones. For the most part I find USB power good enough to satisfy. As a DAC only I can' really hear any difference which means the USB power supply is well sorted. And I can't imagine an instance where I'd mess with that internal gain jumper - perhaps running the HE-6 without an external amp? An unrealistic scenario to be sure. 
 
I switched to my Noble Audio K10 custom IEMs and was somewhat disappointed. The DX1 has rather large amount of gain which means volume is unnecessarily high. There's very little usable range with sensitive headphones and IEMs seem to universally show more background hiss than I'd like. This is disappointing since the older models were very usable with IEMs. The only good match I was able to find was using my Lear LCM-5 custom IEMs with their Monitor Tune Adaptor. This brings impedance way up into the 300 ohm range and drops sensitivity as well, allowing these otherwise highly-sensitive IEMs to work well even with tube amps. The DX1 is an excellent match in this case, but unfortunately this is not representative of the usual IEM experience. 
 
Since the headphone amp section isn't significantly changed - the new opamp still drives the same amplifier chip - I strongly suspected the DAC portion was responsible for these improvements. To test this, I let the DX1 do DAC duty with some heavyweight dedicated amps - the SimAudio 430HA, Violectric V281, and Questyle CMA800R. I would normally reach for my Stax setup in this situation but my KGSSHV amplifier has just a single pair of XLR inputs and is thus not the easiest to use with a pair of single-ended DACs. In any case, using external amplification confirmed my theory - the DAC portion of the DX1 contains the exciting sound signature, while the headphone output remains largely neutral. I do think the Muses opamp allows for a more revealing performance but it comes at the expense of background noise on sensitive headphones. So it's a trade-off which some people might prefer not to make. Swapping the headphone opamp is always an option but I haven't spent time on that just yet. It would be fun to try out something like the Burson Supreme V5 discrete opamp though I'd have to double check the literature to make sure the Audinst circuit meets the proper voltage requirements.  
 
It sounds like I'm complaining about the headphone section. And to some degree I am. I'm thinking Audinst has reached the limit of this particular setup and may need to revisit their choice of TPA6120A2 next time around. That said, the DX1 still sounds remarkably clean and clear using the right headphones. K812, as mentioned, but also the LCD-2 and HD650, and to a lesser extent the HE500. I wouldn't go any brighter than that - I'm thinking HE560 is going to be a problem - but stick with neutral or somewhat darker headphones and you'll be pleased with the results. K812, a seemingly bright headphone at times, seems to be an exception which somehow just works really well regardless. 
 
As a DAC, I'm far more enamored with the DX1. It doesn't feel like a weak link even when mated with very nice amplification. I even ran it in a speaker-based setup using a Jeff Rowland pre, Parasound Halo amplification, and Sonus Faber speakers. And guess what? Among these multi-thousand-dollar components, the little Audinst didn't stick out like a sore thumb. In fact it sounded right at home while playing DSD tracks fed by a Surface Pro 3. The bold, exciting sound remains controlled in the upper mids and highs, with very little glare, and is backed up by an impressively solid low-end response. As enjoyable as the mx2 was, I put it in this system and it quickly feels out of place. Boring, dry, flat; a cardboard cutout of what the DX1 is capable of. 
 
I find DSD capabilities to be generally useful despite the limited amount of music available. I actually started ripping my SACD collection and am enjoying that stuff more often than my collection of DSD downloads purchased from various sites. The selection feels more relevant for day to day listening. The process is no fun but I've finished most of my discs so I can't complaint much. I'm glad the little DX1 can handle DSD and DXD too, but I wouldn't call that a must-have feature on a device like this. It's becoming more of a standard thing and if it matters to you, great, but I suspect many people won't care all that much. 
 
More important to me is the improved overall performance. Take the combination of superior DAC, vastly improved USB processing, and those expensive Muses opamps, and the DX1 becomes a formidable competitor in this crowded field. The problem, however, is exactly that - there are TONS of excellent devices to choose from in this space. If someone could stretch to $499 I heartily recommend the Grace Design M9XX. It's arguably the better DAC and very easily the better amp. Only problem is the limited availability - Massdrop and Grace Design only launch batches here and there, and it's often sold out. Audinst is available right this second and trumps many others I've heard in this class such as the Pro-Ject Headbox DS and PS Audio Sprout (though I find the Sprout terrible so it's not really tough competition). Actually, now that I think of it, this is a somewhat unusual pricing area. Lots of stuff is available around $200-300, much of it portable or semi-portable. And then there's a lot out there in the $500 to $600 range, most of it decidedly non-portable. The Audinst fits in between those two categories in both price and feature set. 
 
 
 

 
CONCLUSION
Overall I find the Audinst DX1 to be a solid if not quite amazing entry into the sub-$500 category. It does everything you might want, and sounds (mostly) enjoyable while doing so. The sonic signature is something like a junior version of the excellent Matrix X-Sabre DAC - bold, exciting, and highly engaging. I find it to be an improvement on the HUD-mx2 but I can see how some people may not like this new sonic direction. I do question the high gain on the headphone output but in every other way the device is fairly impressive. Back to my original statement, I'll conclude that the Audinst HUD-DX1 certainly does qualify as another worthwhile budget option to consider. 
 
 
 
 
 
 
 

 
 
Another day, another interesting Massdrop exclusive. It seems to be a trend by now. The first collaboration we saw was with AKG, resulting in the hugely popular K7XX. While based on the discontinued K702 65th Anniversary Edition, the K7XX has some customization in terms of colors, along with a major price drop compared to the original. That's always welcome. Next came the K553Pro - now a standard model in the AKG line and available elsewhere, it was nonetheless exclusive to Massdrop for several months upon release, and again had a lower price than elsewhere. See the trend?
 
Next, Massdrop collaborated with pro audio veterans Grace Design to come up with the Grace m9XX USB DAC/amp. That little dynamo seems to represent the direction Massdrop wants to go with these things - not just rebadging or exclusive early releases (although those may still have their place) but actually working with a designer to create a unique product. And of course releasing it at a very competitive price. 
 
The latest project is a joint venture between Massdrop and Fostex. While Fostex may be primarily known for their popular line of planar magnetic headphones (beloved by DIY modders), they also make studio monitors and lots of other gear - including the highly regarded TH-600 and TH-900 headphones. Those models are an evolution of the older Denon D7000 family which Fostex actually created for Denon.
 
Massdrop collaborated with Fostex resulting in a new member of the family which, in keeping with Massdrop's naming conventions, is dubbed the TH-X00. And it's very obviously a sibling of the existing models. We get the same magnesium frame, and the same long 6N oxygen free copper cable with fancy 1/4" termination. Massdrop's version has some variation which distinguish it from either sibling without departing too far from the successful formula. 
 

 
 
The first, and most obvious difference, is found in the cups. While the TH-600 has black magnesium cups, and the TH-900 uses beautiful Japanese birch maple coated with Urushi lacquer, the TH-X00 cups are mahogany with a clear coat finish. Mahogany is a hardwood with plenty of inherent variation. So each TH-X00 has potential to look somewhat unique - think Audio Technica woodies or the Lawton Audio aftermarket cups, where the theme is always the same but subtle variations do exist. Check out these pics to see how the look has subtle changes based on lighting and angle. These are VERY nice cups, better imho than the original D7000 and up there with some of the better aftermarket options I've seen.
 

 

 

 

 

 
 
 
The next difference is the driver itself, which I'm told is very similar but not quite identical to the others. All models use drivers sporting 50mm "Biodyna" diaphragms (a Fostex name for bio-cellulose) and powerful neodymium magnets.The TH-900 claims a 1.5 Tesla magnetic flux density for a sensitivity of 100dB/mW, and the TH-600 claims 1 Tesla resulting in 94dB/mW. That's the main difference between them in terms of specs. I'm told the new TH-X00 is rated at "over one Tesla" which may place it somewhere in between the two siblings. Interestingly, sensitivity is listed on the box as being the same as TH-600, so I really don't know what to make of it. 
 

 
Last but not least is the unique pad design which is completely different from that of the TH-600 and TH-900. While those models use a somewhat thin pad which is generally rounded, the TH-X00 has a thicker, asymmetrical design, angled much like the old JMoney pads if not quite as thick. They may actually be closer to the original Denon pads from the D7000 and family. I'm having trouble recalling those since I almost immediately swapped mine out and never used the stock pads again. In any case, Massdrop says the TH-600/900 pads made a huge contribution to their sound signature; and not necessarily in a good way. These new pads are designed to help "tame" the somewhat bright/harsh top end, making for a more smooth, natural presentation. 
 
 
 
 

 
 
LISTENING
First, let's start with the basics. If you've ever worn the similar Denon or Fostex models you'll know exactly how this goes. They are well made yet very light weight which is refreshing in this world of heavy planar designs. The headband, which at first might not seem particularly well padded, ends up being perfectly comfortable due to the low weight. The adjustment mechanism feels solid, with the yolks using the improved hinge system from the Fostex TH models. Apparently the old Denons were known to fail in rather high numbers (mine never had an issue). That, or they just squeaked like crazy. So Fostex changed the design to use a self lubricating washer - problem solved. 
 
If you're new to the "family", and looking for a great sealed headphone... be aware that these things don't isolate much. The somewhat loose fit combined with the cup design makes for little sound reduction in either direction. So, you'll hear people talking in the room next to you, and they might hear your music if played loudly. They still don't leak as much sound as a true open headphone. We're talking isolation/leakage just barely surpassing "semi-open" models like the beyerdynamic T1. Keep the volume reasonable and you should have much trouble - just don't expect complete silence and isolation. 
 
Impedance is 25 ohms meaning these things can be driven comfortably from low power sources. A quality smartphone will sound very respectable (you'll need an adapter for the 1/4" plug though), though it obviously won't unleash the full potential of this headphone. They don't need a powerhouse amp in terms of juice but definitely scale well with more a resolving chain. A higher gain desktop amp may actually be problematic when it comes to range of volume adjustment. I ran into that with a few devices including my Questyle CMA800R which sounded killer but was tricky to dial in "just right". I ended up having excellent results with many of the better integrated DAC/amp units I have on hand. The Questyle CMA800i, B.M.C. UltraDAC, Aurender FLOW, and Anedio D2 all drove the TH-X00 exceedingly well. Those results are clearly linked to all the units having very low output impedance, very low noise, and reasonable gain. And, of course, the Massdrop exclusive Grace Design m9XX was a dynamite pairing. It has all the juice one might need, and that top-mounted volume control is a joy to use. 
 

 

 

 
Unfortunately, my ears prove somewhat incompatible with these new pads. The initial fit seems cramped, like I have to maneuver my ears in a certain way and almost "tuck" them into place. If not, the rear of the pads sits on the helix of my ear, which is not the most comfortable thing for long term listening. The pads are made of a protein leather which seems very similar to those on the TH-600/900 (which Fostex calls "eggshell membrane"). I didn't have trouble listening to the TH-900 for hours, so I'm thinking it's the shape I have an issue with rather than the material. Massdrop tells me they have not heard any other complaints from other testers so this is likely an issue unique to my big, weird head. If you achieved a good fit with the Denon D2000 and friends, you'll likely be fine with these too.
 
Having fit issues makes it somewhat tough to judge these as I normally would. I just can't put in the hours of listening required to nail down a final conclusion. So I'll have to temper my excitement a bit. Thus far I REALLY like what I hear though. TH-X00 seems to take everything I loved about my old D7000 as well as the TH-900, fixes a bunch of the problems, and sells it for a much lower price (I'll get to that shortly). What's not to like?
 
The first thing that strikes me about these things is the bass impact. This was something I loved about my D7000, and loved even more about the TH-900. Yep, it's still here, not at all diminished. It hits hard and goes extremely low, with killer sub-bass extension that few other headphones can match. I like to think of the LCD-2 as having great bass but when I compare the TH-X00 to my LCD-2 (pre-Fazor) I'm surprised to find the Audeze somewhat soft in comparison. A little indistinct, where the Massdrop/Fostex collaboration has more definition, or more meat for lack of a better word. Bassheads will love this sound, though I suspect most "regular" folks will too. This is not the type of droning, overbearing thump that tends to annoy... this is excellent, high quality slam which does not step on the mids in the least. If you listen to classic rock or jazz or grunge or pop, these will sound energetic and fun, not necessarily neutral but not too wacky either. If you play something with more propensity to show off bass - Pendulum, Blackmill, Pinch & Shackleton, that sort of thing - the TH-X00 will rumble like few other headphones - but even then it won't become a one trick pony like a Darth Beyer. The bass gets low and loud but remains controlled and doesn't come at the expense of any other frequency.  
 
The next aspect I enjoy is how open sounding these are. Completely different from the stereotypical "boxed in" feel of many closed headphones, these things could easily be mistaken for open or at least semi-open cans. Soundstage is large and effortless. It won't compete with my HE-1000 and HD800 but for a "closed" headphone it is among the best I've heard. Imaging is accurate but falls a bit short of the best. Still, nothing to complain about here, these things are impressive. You'll definitely want to drive them from an amp with low output impedance. These are among the lowest impedance full size headphones you'll find, so tube amps are generally not such a good match (though I'm sure exceptions can be found). 
 

 
Highs are one area where I feel the TH-X00 is actually better than the TH-900. I don't hear the same sharpness around 6 or 7 kHz, yet I also don't feel they have diminished capacity for revealing microdetail. While my Stax or HD800 won't feel threatened by the detail retrieval here, the TH-X00 still digs deep enough to satisfy in most situations. I'd call it a good balance, where cymbals ring out with characteristic splash, and brass instruments have the appropriate amount of "blat". I can see how die-hard TH-900 fans might find this model lacking in excitement... but I could also make a case for them being thrilled that the treble is less splashy without losing much energy overall. It's hard to say as everyone describes the TH-900 a little different. Regardless, I think these will prove less polarizing overall due to their superior technical performance. 
 
Midrange initially seemed more forward compared to my recollection of the TH-900. After more listening I'm still not sure if that's really the case, or if it's merely a byproduct of the superior treble-to-mid ratio. But when I listen for that characteristic midrange dip from the TH-900, which seemed centered around the critical 500Hz range (give or take), I'm not really hearing it here. Maybe just a touch, but very, very minor. I heard a D7000 not long ago that I really enjoyed, and the owner told me it came from one of the last batches made prior to the line being discontinued. It sounded remarkably better than any D7000 I had heard before. I've heard other reliable sources (Tyll included) mention the same thing. Apparently Fostex got their act together on the later models, resulting in a more linear presentation than before. Well, I'd say the TH-X00 has a lot in common with those. Mids are still lush and creamy, but this time around singers aren't buried quite so deep in the mix. This headphone makes a great counterpoint to the HD800 for those times when I just want to let the music flow. 
 
Did I mention these things will go for $399? Yep, $399 for what is arguably a better headphone than the $1,299 TH-900. Very likely better, based on my admittedly limited experience, than the TH-600 which after recent price drops still goes for $599. The Denon D7000 was $999 before being retired and this TH-X00 is easily on par with that as well. So we're talking killer value here, without a doubt. 
 
My only reservation is the earpad fit. They just don't work all that well - FOR MY EARS. Not saying that will apply to anyone else but me. Which makes me curious to read the other reviews once this posts, as I can't reliably say this same sound will be heard by others. I had grand plans to pick up a bunch of different pads and see how they work, but unfortunately I ran out of time. So far all I have is the velour pads from my K7XX which don't fit permanently but do stay in place when worn, as a sort of "proof of concept". They sound different, more neutral in the lows and a tad brighter, but still quite enjoyable. This leads me to believe I'm in for quite an adventure rolling pads. I can't even recall which ones actually fit without too much trouble. Alpha Pads? Beyerdynamic velours and gels? HM5 pads? Surely at least SOME of those will fit well. I may have to try the Lawton angle pads too. I wish I still had my old JMoney pads as those were just about perfect on my D7000. 
 
In any case, Massdrop and Fostex have achieved something pretty special with this release. I almost feel bad because new TH-600 sales will probably drop like a rock after these come out. Maybe Fostex has plans to retire the 600/900 soon anyway. If you're in the market for a "fun" or "musical" headphone, don't want to spend a fortune, don't want something so ridiculously colored that it only works with a few genres, and aren't willing to put up with major flaws just to get your bass fix, the TH-X00 is absolutely recommended. 
 
The product page can be found HERE and ordering goes live on Friday the 27th. This drop will be limited to 2000 units.

Ever hear of Pure Piper? Neither had I until the company recently sought me out, asking if I'd be interested in trying their new A2 device. They found me at a good time when I happened to be (briefly) all caught up with reviews, and their pricing ($269) seemed very reasonable. So I agreed to give it a shot, making no promises as to what the result might be or if I'd even publish a write-up at all. This is actually pretty standard for me - I get a LOT of gear passing through that I don't end up writing about, for various reasons. 
 
While the review unit was in transit, I did a little research on the brand and found this review from back in 2010. The A1 was the first DAC released in the North American market, sans headphone output or preamp capabilities, but otherwise having a lot in common with the A2. Their claim to fame was a discrete output stage and excellent value for the money, including a more substantial enclosure than what we usually see for around $200. That was back in a time where a company could get away with releasing non-USB capable devices. Those days have passed, and the new A2 is somewhat more modern.
 
I say "somewhat" because the device still keeps it simple. Apologies to Schiit Audio for using one of their slogans, but there's a distinct lack of "buzzword compliance" here. USB runs in adaptive mode and tops out at 24-bit/96kHz - a far cry from the recent parade of DSD and 384kHz capable models. There's also coaxial and optical digital inputs along with a 3.5mm analog input for connecting a smartphone or tablet. Outputs are single ended only, as expected in this price range. We do get separate jacks for fixed and variable output which is not something I see all that often in DAC land. Up front, a 1/4" headphone jack flanks the small 2-digit LCD display and a set of 4 buttons. Two buttons handle volume up/down, one cycles inputs, and one is used to activate the "balance" option, for adjusting left/right balance on the headphone output. Again, not something I see very often, nor something I have any particular use for. 
 

 
Internally, the A2 is reasonably capable. DAC duties are handled by the Cirrus Logic CS4398 - again, no buzzworthy Sabre chip on board. Digital inputs are handled by the venerable Cirrus CS8416 while the USB transceiver is a Bravo SA9023. The Bravo is a somewhat rare 24/96 capable budget chip about which very little information is available. However, based on what I could find, this solution is superior to the competing Tenor TE7022 in every category: better jitter rejection, support for the 88.2kHz sample rate, and improved interfacing with digital audio receivers. As such, this affordable chip is a great choice for a budget design like this, where many others still use the old Tenor solution. Interestingly, the A2 is one of the few devices I've encountered to reliably accept 176.4kHz and 192kHz over Toslink. Most DACs top out at 96kHz when using optical. So, while USB is limited, both SPDIF inputs can go all the way to 192kHz, if that matters to you. 
 
 

 
The power supply is a linear design complete with torroidal transformer, which is not often found in this price range. A lot of budget DACs simply don't have the real estate to handle a linear power supply, so they opt for an external power brick or wall wart. This one aspect is likely responsible for the difference I hear between this device and so many other budget contenders. I'm reminded of the excellent Parasound Zdac and Zdac v2, both of which are based around a beefy power supply despite their relatively compact size. The Parasound models are similar to the Pure Piper in that they may not have the latest and greatest USB implementations, but nonetheless prove worthwhile due to their solid grasp of design fundamentals. 
 
 

 
Pure Piper uses a Cirrus CS3310 digital volume controller which should theoretically be superior to the on-chip scheme of the CS4398. This chip lies in the signal path of the "variable" line-out and the headphone amp, but not the "fixed" RCA output. The A2 uses opamps such as the OPA2134 and OPA2604 for low pass filtering and I/V conversion, with a capacitor coupled output stage using large Pure Piper branded caps. Headphone output is a classic NE5532 driving a discrete transistor buffer. Output impedance is around 4.5 ohms, so there may be issues driving some IEMs due to impedance related interactions. The amp tops out at nearly 2W at 32 ohms so most headphones should be very comfortably driven.
 
 
 

 
Build quality on this thing is surprisingly good. It's not flashy, but in a way still looks like a more expensive device. It helps that many in this price range are really compact or else just look like toys, while the A2 has a proper enclosure and is larger than most. It really is built like the proverbial tank, reminding me somewhat of the original Matrix M-Stage headphone amp, or the Apex Peak/Volcano combo I used to enjoy so much. The only evidence I find of cut corners is the captive power cord. Since the device uses a linear power supply rather than the usual switch mode solutions often found in affordable DACs, it's more complex to offer universal voltage. So the unit is designed to work with 210V-230V wall power only, and the cord can't be replaced. Instead, Pure Piper sent the A2 along with a small voltage converter to allow use in my region. I'm not sure if that's a common thing they always do or if it's special for the review. It's a little cumbersome but gets the job done well enough. 
 

 
 
 

 
Now, on to sound. The Pure Piper A2 is surprisingly capable for a sub-$300 device. It's got a dynamic, full-bodied presentation that remains detailed and thoroughly engaging. I'd call this a "musical" sound without the negative connotations that word can sometimes bring. Low end heft and extension are more convincing than most of the affordable DACs I've tried. There's a slight bloom involved, so don't expect strict neutrality, and the level of control isn't on par with something like a Resonessence Labs Concero (which, to be fair, costs roughly twice as much). But I think most people would really enjoy the end result here. Mids are thick and rich, while upper mids and highs seem very slightly accentuated. It's just a slight boost, small enough to go unnoticed at times but also to add drama with certain music. The highs do seem a tad rolled off in the extreme upper registers. It's enough to notice missing "air" as compared to higher-end sources, but not something I would complain about in general. Overall it's a crowd pleasing signature which works well with the majority of music I throw at it, being something like a junior version of the Matrix X-Sabre thanks to its exciting sound signature. The Pure Piper isn't as refined but again that's to be expected considering the price discrepancy. 
 
The fixed outputs sound pretty much identical to the variable output, so apparently the volume controller chip placed in the signal path has no audible impact. That, or the device just isn't transparent enough to show a difference. I listened long and hard for this - I expected at least some small difference to rear its head at some point. I thought I might have heard it initially, but it vanished whenever I tried to nail it down. So, bottom line, both outputs sound close enough to be indistinguishable. And I actually like having both outputs available. I threw the device in a desktop rig using a pair of Serene Audio Talisman powered speakers connected to the variable output, along with a NuForce HA-200 headphone amp being fed from the fixed output. This might be a somewhat uncommon setup, but the A2 allowed it to happen.... so I won't complain. Without the multiple outputs I would not be able to accomplish the goal.
 
 

 
One thing I noticed about the DAC section of the A2 - it is very susceptible to transport quality. This is something I used to find quite prominent back in the day, which has somewhat lessened on modern DACs. Especially those with quality USB inputs. I no longer think asynchronous USB is a magic bullet, as it was originally purported to be. However, modern DACs tend to sound at least "pretty good" even with basic USB signals from any old computer. DACs like the A2, using adaptive USB and lacking any specific jitter reduction techniques (ASRC or FPGA for example), remain highly transport dependent. It does better with my Surface Pro 3 than my cheap little Acer laptop, and better still using a dedicated server such as the B.M.C. PureMedia or Aurender X100L. SPDIF is just as sensitive - it likes my YBA Design CD player as transport quite a bit more than my basic Sony Blu-Ray player. The aging CS8416 is not the best DIR for jitter reduction, and the Wolfson WM8805 or TI PCM9211 would have been superior alternatives. But a lot of designers seem to prefer the old 8416 for some reason.... I've heard much talk of it having a more "musical" sound to it, so perhaps it was chosen in spite of the other (technically superior) options. The A2 would very likely respond well to jitter reduction devices like the Audioquest Jitterbug, Uptone Regen, iFi iPurifier, et al. I don't have any of those specimens on hand at the moment, so I'm basing that assumption on the results I get using a DDC such as a Resonessence Labs Concero or Audiophilleo 1 with PurePower. Obviously those are both overkill considering the cost, but the point remains that "decrapifying" the incoming signal pays dividends with this device.
 
The amp section drives most headphones with plenty of juice. Planars like the LCD-2 and HE-500 hit with characteristic authority, showing the benefit of this powerful amp stage. Dynamic headphones like the AKG K812 and Ultrasone Edition 12 also show increased punch which may or may not be a good thing... at times I felt like it made things more exciting, while other times it went a bit too far. I'd say the integrated amp section is also warm and exciting, similar to the DAC - meaning the combination ends up being a bit much at times. It does a credible job 90% of the time, with most music and most headphones. But I did notice an unpleasant "tizz" which shows up on certain female vocals. Folk singers Alison Krauss and Abigail Washburn, two of my favorites, are not very enjoyable with the AK T5p, AKG K7XX, Ultrasone Edition 12, or any number of other headphones. Same with Canadian singer/songwriter Chantal Kreviazuk - I've never heard her sound sibilant like this before. Darker models like Sennheiser HD650 are more palatable but still not ideal. It's odd because, using the same problem-inducing headphones, I can still enjoy other female vocalists (Kristin Andreassen, Thao Nguyen, Aoife O'Donovan, Sarah Brightman, etc) without a hitch. They may have an accentuated presence in the vocal range but that sibilance is nowhere to be found. So, apparently it's a case by case thing.  
 
Unfortunately, the headphone amp is not a good match with sensitive IEMs. There's an unavoidable hiss which is overpowering, and the output impedance isn't a good match anyway. So scratch IEMs off the list. I do not hear any hiss with full size headphones, no matter how sensitive. 
 
Ultimately the Pure Piper A2 is a satisfying if somewhat unremarkable device, and I mean that in the nicest possible way. It's strength ends up being its lack of significant drawbacks, where many entries in this range have one or more glaring flaws. The build and appearance of the A2 are quite good for the money. And the powerful headphone output is more impressive than most other budget integrated DAC/amps I've experienced - especially with planar magnetic headphones. A solid argument could be made that a majority of a system budget should go towards the headphones themselves, with ancillaries being a distant second. Following that logic, I'll happily recommend the A2 as paired with an HE-560 to name just one example. Are their better devices to be found? Of course, though none currently come to mind in the sub-$300 range. Pure Piper may not be a well known player in the North American Market and honestly I don't think this device will change that situation much - but the A2 shows me they can make a solid product for a very reasonable price.
 
A quick browse their website reveals much more than the A1 and A2: I see some far more advanced DACs, some big Class A amps, preamps. speakers, cables and various accessories, and even some headphones. Looks like they have a full line of gear that isn't currently available outside their home market. If the quality of the A2 is any indicator, perhaps they should reconsider their distribution. The company seems to have recently started selling on eBay which is where you can purchase the A2 if you find yourself intrigued enough to give it a shot. 

Nowadays, there's more headphone-oriented gear on the market than you can shake a stick at. Headphones are abundant. Headphone amps come in a wide variety of styles, prices, and topographies. And plenty of DACs now feature quality onboard headphone amplification. It's a headphone lover's dream.

Things were not always this way. Go back about 10 year, and there was far less of.... everything. In particular, if you wanted a quality all-in-one DAC/headamp solution, choices were rather limited. The major contenders came not from audiophile brands but rather the pro audio world. We had the Benchmark DAC 1, the Lavry DA10, the Grace Design Model 901, and - to a lesser extent - the Apogee Mini DAC. All offered what was considered at the time to be exceptional D/A conversion, with at least a reasonably nice headphone output, in a decidedly pro-audio oriented package. And the price on most of these approached $1k which was not a small sum back then. The Grace Design unit set itself apart by selling for $1,500 and by referring to itself primarily as a headphone amp - D/A conversion was also part of the deal, but the lack of analog outputs meant headphones were the only way to listen.

At the time, I cycled through all four models in my search for headphone bliss. I quickly eliminated the Apogee as being sub-par compared to the trio of Grace, Benchmark, and Lavry. All three models had their strengths and weaknesses, such that I enjoyed them all in their own way. This was a hot topic on forums at the time. It seems like many headphone enthusiasts were coming to the same conclusions I was: the Benchmark was crazy detailed but somewhat bright and unforgiving. The Lavry was creamy smooth and could be described as the most "analog" sounding. The Grace was perhaps the most balanced of the lot. All three models had their fans and a few detractors too, as is usually the case with most gear.

The m901 was my favorite option for driving my reference headphones, which at the time consisted of models like the Audio Technica L3000, Grado RS-1, and of course the Sennheiser HD600 which was standard issue for enthusiasts back then (and probably still should be). I wasn't in love with the 901's DAC portion, but the headphone stage was phenomenal. I often paired the Lavry as DAC with the Grace as amp, playing to the strengths of each model. Then along came the Grace m902 which I felt significantly improved the DAC section. While perhaps still lagging slightly behind the Lavry, it was close enough for me to sell the DA10 and stick with a one box solution for a time. It was also novel in having a USB input with which I took my first steps in computer audio. Very few devices had USB inputs at that time. But as other stuff hit the market I eventually moved on - you know how it goes. Grace had success with their m903 and more recently the m920, both of which seemed competitive in their field. I have heard both but not extensively. My point is, Grace Design has made catering to us headphone enthusiasts a priority for over a decade by now, so they have some expertise on the subject.







The range between $1,000 and $2,000 is jam packed with killer DAC/headphone amp combos. I'd say that's probably where you'll find the best value, in terms of gear that approaches state of the art but doesn't cost more than a new car. As you drop lower than that, it becomes more of an exercise in priorities. I'm not saying there aren't some solid devices out there. There's just usually some sacrifice involved. Maybe the headphone out isn't all that great. Maybe the USB implementation isn't on par with the alternatives. Maybe the amp does great with full size cans but doesn't play well with IEMs, or maybe it's the other way around. The trick is figuring out how to minimize weaknesses while packing in all the stuff us HeadFiers want most. Not a lot of devices nail those objectives.

One option, however, recently made its way to my audio rack, and it's worth talking about - the Grace Design m9XX. The product of a joint venture between Grace Design and Massdrop, the m9XX will go for $499 and should be available to order in a few days. It's a Massdrop exclusive, just like the AKG K7XX which I enjoyed so much - bonus points for sounding marvelous when paired together.

Now, for $499 I don't expect miracles from an all-in-one device. Typically we might get a pretty good DAC with a mediocre headphone amp, or vice versa. Not this time. The goal of the projects seems to have been packing most of the audio magic of the m920 (which at $1,999 is very highly regarded), stripping away many of the potentially unnecessary features, and ending up with a killer, somewhat minimalist device which performs way above its price.

While the m920 and previous generations were all half-rack sized (just like the Benchmark gear and many other popular DACs), the new m9XX is a compact little thing. At 4 inches wide, 5.25 inches deep, and less than 2 inches tall, this thing takes up very little space. Which makes it perfect for desktop duties where a larger device just wouldn't fit so well. I called the m9XX "somewhat" minimalist because, while it may lack quite a bit compared to the m920, it still has a reasonably advanced feature set considering the compact size.

Let's explore: on the input side we get XMOS-based USB capable of hi-res PCM as well as DSD64 and DSD128. There's also a Toslink input with the usual 24/96 cap. Outputs come in the form of RCA line-out as well as dual 1/4" headphone jacks, one of which automatically mutes the line-out when a headphone is inserted. Notably, Grace includes their proprietary crossfeed option for those who might find it appealing. This is a welcome feature as not many devices in this price range have the option. And Grace's crossfeed implementation has always impressed me, being less heavy handed than most - I find it particularly useful with older recordings using hard-panned mixes which clearly favor speakers over headphones, but it's subtle enough to use on modern mixes if the mood strikes. With certain headphones and music, it really does help bring the recording further "out of head", while in other cases it isn't as useful.

And that's about it. There really isn't much more room to add inputs or other options even if Grace wanted to. As it stands, they had to use micro-USB connections to save space. Yes, I said connections in the plural.... let me explain. The right side is what I'd call a "normal" USB input. It handles both power and data, allowing me to use the m9XX with my Surface Pro 3 without a mess of cables. This configuration gets us what Grace calls "low power mode" which delivers something like 160mW per channel RMS into a 32 ohm load, and roughly double that into 50 ohms. This is plenty for your Grado, Audio Technica, Ultrasone, and other sensitive headphones, and more than enough for pretty much every IEM on the planet. I also believe Grace Design is being careful not to boast using peak power, which is often done by marketing departments. If they wanted to sound more impressive they would mention the peak output for a single channel which is quite a bit higher. Need more power? That's why Grace supplies that extra USB input. By adding a second USB cable for power and using an adapter similar to a cell phone charger, the m9XX jumps up to over 1,000mW per channel at 32 ohms. Now we can run most planar magnetic headphones with very satisfying results. And with a corresponding boost in voltage we also get excellent sound with higher impedance models from Sennheiser and beyerdynamic. Again, very impressive considering the compact dimensions of this thing.

Let's talk user interaction, as I find it very well done here. The entire top of the enclosure is reserved for the multi-function knob which spins and presses to accomplish volume control and option selection. Hold it down to access the menu, which leads to options like crossfeed, startup volume memory, and 4 selectable digital filters. The display is a simple two-digit LCD with another small dot being used to indicate "on" or "off" for a function - see my pictures to help illustrate. It's a surprisingly simple yet effective system which I got the hang of immediately. The volume knob reminds me a bit of the old Ortofon HD-Q7 amp, which is quite a compliment with respect to aesthetics and usability. In fact, this entire design is somewhat reminiscent of that under appreciated little amp, which I've always felt absolutely nailed the design portion if not quite the sound quality category. The large button/knob on the m9XX is very precise, matching perfectly with the volume adjustment which is handled in .5dB increments. Overall the m9XX is a joy to use which isn't something I can say about every DAC, including some expensive models.

The heart of the DAC design is AKM's flagship AK4490 chip. This is a fairly new model, released within the last 2 years or so, and is not all that common as of yet. HeadFi folks probably recognize it most from its recent appearance in the updated Schiit Bifrost DAC where it replaces the older AK4399 used in the first gen model. It also shows up in the new (and rather expensive) Lindemann Musicbook series. Aside from those two brands, I'm not aware of anyone else using it thus far. AKM DACs in general don't seem to be used as often as Wolfson, Cirrus, TI, and ESS, so it's hard to know what to expect. Of course, the DAC chip itself is only one small piece of the puzzle, so maybe it's best we don't come into this with preconceived notions anyway.

I already mentioned the XMOS USB implementation, which ends up processing the Toslink input as well. A unique hybrid analog-digital phase-lock loop system (PLL) helps reduce jitter which is especially useful for Toslink, being more likely fed by a lesser source such as an Apple TV. Extensive power filtration is employed to make sure the noisy USB connection isn't fouling things up. Grace uses a total of 5 power supplies including separate supplies for the XMOS implementation, the DAC, and the analog stage. 5V USB power is converted and augmented by a proprietary system allowing the device to run +/- 9V rails on basic USB power, and +/- 14V when running in high power mode with the power adapter. I won't go into it too far but again this shows the expertise involved, especially for a small and relatively affordable device such as this.

The headphone output is built around a Texas Instruments THS6012 transimpedance/current feedback amplifier. I have not seen this particular chip used in this application before. More typically, we see chip amps based on either the TPA6120A2 (quite powerful but usually requires 10 ohm output impedance for stability) or the TPA6130A2 (stable at lower output impedance but far less powerful). Nothing wrong with either, but I was pleased to see something unique being used which seems to combine the best of both the TPA options. Output impedance is well below the magic 1 ohm mark - at 0.08 ohms, listeners have nothing to worry about even with IEMs sporting wacky impedance curves. And I already mentioned the output which is very robust indeed.






Now, after all that, how does the m9XX perform? In my humble opinion: it's really something special. Neutral, resolving, clean-as-a-whistle, the m9XX is an excellent monitoring tool. Paired with a nice set of active monitors, this setup allows one to hear deep into the mix, with a level of transparency few compact DACs can match. It pairs quite well with the AMT tweeter in my Adam Audio F5 monitors - a tweeter known for its expressiveness, not to mention ability to expose sources with poor timbral accuracy. Top end air and extension are without reproach, making it hard to believe this DAC/speaker combo sells for just a bit over $1k. I've heard big rigs using expensive/exotic speakers which utterly failed at reproducing the brassy tones of a trumpet, the shimmer of a crash cymbal in all its glory, or the quick attack of a piano strike The m9XX/Adam F5 combo excels in all three of these tests, proving one needn't spend a fortune to achieve lifelike sound.

Despite its clarity, I wouldn't necessarily characterize the m9XX as a clinical, dry sounding DAC. It's got enough resolution to pull out gobs of microdetail, but it also maintains a connection with the music which is lacking in many pro-audio style DACs. The result is closer to what I remember from the old Grace 901 - balanced, organic, well rounded, not lacking in detail but not shoving it down your throat either. I actually think the little m9XX would compare favorably with the original 901 in terms of DAC performance - that would be a fun comparison if I still had a 901 around. Unfortunately I don't, but I do have several more recent DAC comparisons which might help illuminate the flavor of this device.

The Parasound Zdac V2 ($549) is a very enjoyable DAC. It falls on the warm and smooth side, with a dynamic punch that may exceed what the m9XX can offer. In contrast, the Grace unit is more resolving, cleaner, and more airy in tone, with a more precise soundstage and accurate imaging. I really like both models and would choose among them based on what associated gear makes up the system.

The Rega DAC-R ($1,195) is also a warm and smooth DAC, but I find it troublesome in that it lacks the dynamic bombast of the Parasound, while going even farther into warm/smooth territory. Consequently, it feels like a wet blanket, where music just plods along with no emotion. It can be helpful for taming bright systems but that's about it. The Grace m9XX is superior in most every way, to the point of this really being no comparison. I know a few people who really enjoy what this DAC does, but I just don't hear the appeal based on extensive listening. Maybe my unit is a dud.

The Musical Fidelity MX DAC ($999) is the first Musical Fidelity product I've actually enjoyed in quite some time. I'm told there's been some restructuring at the company and some new blood brought in - hopefully this brings about good things, as Musical Fidelity used to be a big player in the headphone world with their compact X-series components. The MX is a very pleasant DAC where nothing stands out as objectionable - a good thing considering the funky performance of the previous M1 DAC and its variants. The more I listen, the more I like it, and find it very similar to their $2,500 M6 CD player I used to own - perhaps even better. By comparison, the m9XX is just as transparent, just as engaging, and at half the price, is a far better value. And that's before we consider the headphone amp functionality. Bottom line is that I really can't tell these two apart, so there's no way I'd spend double on the MF product, despite it being a very competent offering. If you needed balanced outputs or wanted to stack with the Musical Fidelity MX-HPA headphone amp, the Grace wouldn't work as well, but that's about the only situation I can think of where I wouldn't get the smaller m9XX and call it a day.

MicroMega's MyDAC, at $399, is one of the few devices here small enough to look like a direct competitor to the m9XX. Unfortunately it sounds like there were some compromises involved in achieving this small form factor and low price. It has a focus on transient attack which initially makes for an exciting sound signature, but ends up overwhelming with a busy presentation that becomes unbalanced during long term listening. This is one of those devices that you first demo and think "Wow, I love it!" but later come to hear as fatiguing. The m9XX initially seems a tad boring in comparison, with its measured, even-handed approach. Where's the bite, the snap of the music? After a short time it becomes clear that the m9XX is actually more lifelike, more organic, while the MyDAC is a neon facsimile of reality. This thing received some rave reviews a few years back, and I actually believe those reviewers were genuine in their assessments... they just threw the device in the system, listened for 20 minutes, wrote it up, and moved on. That's why I spend as much time as possible with my listening, sometimes even missing the window of new-product-buzz. I like to be confident in what I'm hearing and that sometimes takes longer than you'd expect.





$500 doesn't buy all that much performance in absolute terms... and when it does, you're typically looking at a dedicated DAC or headphone amp by itself rather than a combo unit like this. So how about that headphone output - is it compromised as we might expect for the price? Thankfully, no. The m9XX sounds very satisfying driving headphones directly. Just like the DAC portion, it strikes an excellent balance between accuracy and musicality, and pairs well with nearly every headphone I have on hand. I'm actually rather surprised at how well it does considering the size of this little box. Apparently Grace knows their stuff.

Straight from a single USB connection which translates to low power mode, the headphone out is exceptional with IEMs. I get a mild, very tolerable hiss with my EarWerkz Supra, JH13 FreqPhase, and Unique Melody Merlin, which my brain easily filters out once the music starts. The rest of the IEMs in my collection play with an essentially silent background: Noble Audio K10, 5C, 4C, and Savant, Dunu Titan, Lear LCM-5 and LCM-BD4.2, the Aurisonics AS-1b, and many others which I'm forgetting at the moment. A volume setting of roughly 50 (out of 99) is typically good for most music, leaving plenty of room to dial in more or less as needed. I'm a huge fan of custom IEMs and it can be frustrating when so many amps - somewhat counter intuitively - can't handle these easy-to-drive little things. I'm happy to report the m9XX passes the test with flying colors. A top-level CIEM can be as resolving (arguably more so) than the best full size headphones, and will often expose weaknesses in a source. Again, the m9XX passes the test with aplomb.


Moving to full-size headphones, the m9XX does a very competent job as well. As I mentioned earlier, some models do just fine in low power mode. The Astell & Kern AK T5P, a rather sensitive flagship closed back headphone, is extremely enjoyable with the m9XX set to volume 60-70. If this was my main headphone I wouldn't ever use the high power mode. Same with the Grado PS500 and the Sony MDR-1A. Of course, driving current-hungry planar magnetic cans like the Audeze LCD-2 provides an obvious excuse to run that second USB cable with the power adapter. Note that gain remains the same, but drive is enhanced. So running the LCD-2 in low power mode with the m9XX already gets me all the volume I could ever need. But the bass performance is weak, and the midrange lacks focus. The whole thing is just soft and squishy. It's clearly underpowered. High power mode doesn't suddenly let me run at lower volume settings, but it does give a clear increase in drive. The LCD-2 regains its authority, with deep, clean low notes and a more insightful midrange. This same experience applies with the HiFiMAN HE-500 and Mr Speakers Alpha Dogs too. There's enough juice on tap in high power mode to get most planar magnetic headphones jumping, with the usual exception of Hifiman's HE-6. I also prefer high power mode with my Sennheiser HD650 and other high impedance models. Interestingly, I even prefer high power mode when driving the AKG/Massdrop exclusive K7XX. It's not the most demanding headphone out there but seems to really "wake up" in response to the extra power. It's handy to have both options available.

Overall the amp section is nearly identical to the DAC - both are clean, transparent, and highly resolving, yet not analytical or dry. The end result compares favorably to any number of more expensive devices I can think of. The original Benchmark DAC 1 for example, is more chalky and etched sounding to my ears, with a glare to the upper mids and a thin character that just don't enjoy these days. When it first launched back in the day, I admit to being taken by its seemingly extreme resolution, but I eventually began to hear it as artificial and obnoxious. Their DAC 2 is far superior to its predecessor and does manage to outclass the m9XX, as it certainly should for the price. The delta is not as large as you might think though. I also prefer the m9XX to the Mytek Stereo 192, which to my ears sounds dangerously close to the original Benchmark DAC 1. The Grace model has more life and soul, sounding better no matter what headphones or speakers I pair it with. The best comparison I can probably think of is the Anedio D2 which was selling for $1,249 last I checked, down from the original $1,470. The little m9XX gives a huge portion of the same ultra-transparent, open-window type of sound, at a far lower price and in a smaller package. I still find the D2 superior but spotting a difference requires some careful listening with excellent recordings - most people would find them very similar under normal circumstances. Those who know my opinion of the Anedio will understand just how big a compliment this comparison really is.






I never intended to turn this into such a long write up. I've got paid articles in progress for InnerFidelity and Part Time Audiophile which I really should be focusing on. But this little device gets me optimistic about what can be achieved through smart engineering and knowing what users are looking for - and what they aren't. Grace Design seems to have whittled down the technology and features of their far more expensive m920 in just the perfect way, while Massdrop allows it to be sold without a huge dealer markup. The initial drop is limited to 500 units and I suspect those will go very quickly - I'm hoping (though I have no verification at this time) that Massdrop will offer more drops in the future just as they have done with the K7XX. In any case, here I am rambling on and on about it instead of working on my "real" articles. Jude will have his say on the m9XX, as will several other experienced HeadFiers, so we'll see if my experience matches theirs. All I can say is that I'm thoroughly impressed by this thing, and think it might be a new benchmark (no pun intended) in terms of sonic results for the price.