Intro and Background
 
[size=11.0pt]Doug Savitsky, founder of ECP[/size] Audio, was nice enough to come over to my house and deliver a loaner unit of his L-2 tube amplifier.  Doug also lives in the Chicago area, so this was much safer and easier than having him ship it.  And it was fun for me - Doug is a very smart guy, and i enjoyed hearing about his amplifiers from him.  He told me a lot about the L-2.  He also told me he thinks his solid state amp, the DSHA-1, is the better sounding amp. Oh well.  I'm a tube guy, mostly, and I wanted to audition the L-2.

Doug's amps are very well made, and very nice to look at:
 






 
The topology here is quite interesting.  I was kind of surprised, and initially a bit put off, that it used balanced inputs, since it is a single ended amplifier.  But there is a very good reason for that, which is that the L-2 uses an input transformer, according to Doug: “The balanced connectors take advantage of the input transformer. With XLRs, the input signal is not connected to ground which helps eliminate noise.” Fair enough.

Further, the L-2 uses a “Parallel Feed” topology.  I was not familiar with this, so I asked Doug about it, and he said:
 
Quote:

In traditional transformer coupled tube amps (often referred to as "series feed"), such as the Trafomatic, Balancing Act, or Donald North's stuff, the transformer is in series with the DC (direct current) feeding the tube. This means that the DC flows through the transformer. DC saturates transformers cores (making them unable to pass a signal) so in order to accommodate this, the transformers must be altered. Specifically, they need to have an air gap in them, they need to be larger, and they need to be made from a material that does not saturate easily (M6 steel). All of these things lower the fidelity of the transformer.

Parallel feed (parafeed for short) changes this topology a bit. Instead of running the DC through the transformer, you instead use a different load for the tube (a choke, a resistor, or a constant current source (CCS)) and capacitor couple the transformer to the circuit. This allows transformer that are not air gapped, are made from better core material (nickel in the case of the L-2) and that are smaller, all of which increase fidelity.  Neither parafeed nor single feed are necessarily "better," but there are times when one option is a better choice. The reason to use single feed is that a transformer is an energy storage device. This means that a transformer loaded tube (single feed) can swing higher than B+ in voltage. So, for a power amp, this makes sense. For instance, a 300B based power amp with a 300V power supply can swing several hundred volts below and above that 300V supply. To do this with a CCS loaded parafeed might require a 500V supply which would mean an extra 30W of heat to dissipate making an already inefficient amplifier much more so. (a choke loaded parafeed can do the same thing as a single feed amp, and in that case, it is just a preference of one topology over the other -- Bottlehead amps are generally parafeed done this way.)

The tradeoff to the above is lower fidelity. That is, the gapped transformer that can swing the volts much be large, gapped, and steel. In headphones, where we only need a quarter watt, this efficiency need drops away. The L-2 wastes less than a watt across the CCSes loading the tube, which seemed OK. And, the advantage is the ability to use a better transformer.

Two more notes -- one oft mentioned con to parafeed is that the transformer is capacitor coupled to the circuit, that cap being in the signal path. This can be an issue in that this can form a resonance circuit (typically resulting in a bass hump) but sizing the cap appropriately eliminates this. Moreover, the parafeed cap as it is called is typically ~5uF in size (small enough to allow the use of a high quality cap -- I use V-Caps) where as with single feed, the final power supply cap is in the signal path, and this is generally a large electrolytic. So, this is really not a downside.

Second, and this is the real advantage of parafeed, as the name suggests, AC and DC current paths are in parallel, rather than overlapping. This means that the AC signal current loop is well controlled in parafeed, travels through less components which tend to be of higher quality, and does not interface with the power supply.

Click to expand...

 
 
There is even more information on this here, for those interested.  http://ecpaudio.com/pdf/parafeed_basics.pdf
 
[size=11.0pt]I present the above information purely as background and FYI.  I’m not taking on faith that any of that really makes the amp sound better.  It’s well reasoned, of course, as Doug knows what he is talking about from a technical perspective, but every amp maker has their own biases.  What matters to me is how it SOUNDS.

I auditioned the L-2 using a variety of my sources, analog and digital.  I ended up using mostly the Ultrasone Edition 8 and Audio Technica W3000ANV, mostly because  the L-2 only outputs about 250 mw, and my other two headphones are the Audeze LCD-3 and Hifiman HE-6, which require more power than that in my opinion.[/size]
 
Sound Thinking

The ECP L-2 is definitely not what people probably imagine tube sound is going to be if they have not heard a lot of tube amps.  It has a very smooth sound, yes, but it's also very neutral and detailed, and not in any way overly warm, lush, ripe, or plump.  In fact, it is much less of all of those things than many tube headphone amps I have heard.  It is much closer totally to my RedWine Audio amp, for example, than it is to my Leben or Decware.  It's quite far from the very lush Decware. 

None of that is meant to be any sort of indictment of the L-2, though.  It has a very enthralling sound that is very nuanced.  Detail retrieval is absolutely first rate, but not due to some shoved forward treble abnormality.  No, it's real detail that comes from suberb transparency, and from a crystal-clean presentation.  As always, this usually works well, but if you are playing a hard, bright sounding recording, guess what? You will get sound that is hard and bright.  There isn't a lot of editorializing going on here.  Play crap, and you will get crap.  Play something well recorded, even reasonably so, and you will get very, very good sound.

I'm not talking here about only being able to enjoy "audiophile approved" recordings.  Yuck.  I was captivated playing "And You And I" from Yes's "Close To The Edge".  I have played that song hundreds of times.  But I actually stopped what I was doing when it came on, shut my eyes, and got lost in it. 

Part of that was definitely a function of the remarkable soundstaging ability this amp has.  The stage is not projected all that far out in front of your head, and yet it has an impressive depth and width to it.  Image specificity was also first rate.  Very nice.

Comparatively Speaking

So an obvious comparison would be with the Trafomatic Experience Head One, which uses the same output tubes.  It's about 2/3 the price, and while also output transformer coupled, with a switchable impedance capability, it is a different topology.  Unfortunately, I no longer had the Trafomatic, so I am going just from memory, but I do think there were some similarities, with the ECP getting the edge in terms of nuance and soundstaging.  I was always very impressed with the Trafomatic, though, and I don't think it is very far behind the ECP.

Slightly more expensive is the Leben CS300, which is my "reference".  The Leben of course is also a speaker amp, and has multiple inputs, a bass control, balance control.  On the other hand, it's transformer coupled with only one winding (32 ohm) for headphones, and doesn't like high impedance cans that much.  It has a lot more output power, though, amd as such, for the LCD-3, ot was a much better choice than the ECP.  And the CS300 also has a more organic, and slightly lusher sound to it.  With the W3000ANV, though, I do think the ECP slightly bests the Leben in terms  of detail retrieval, which is saying a lot, as I think the Leben is excellent in that regard.  The same story for soundstaging - the ECP is just a wee bit ahead.  I slightly prefer the Leben's tonal balance, and its lusher midrange, but for many people, I imagine it will be the reverse. If I had to choose one amp for the W3000ANV, it would be the L-2.
 
And the same for the Edition 8.  The Ed 8 is very efficient, and while I like it a considerable amount with the Leben, I slightly prefered it with the L-2.  The Ed 8 lapped up the L-2's delicacy, and sounded more nuanced than I ever recall hearing it.  That was fun.
 
 
Other musings

Any nits to pick? Well, as I mentioned, the amp does ride the line toward being bright.  It is important to note that the L-2 is NOT bright, and I found it's neutral voice quite alluring.  But it is not lush or warm, and so as always, one should careful what headphones one pairs it with.

Ergonomically, I also have to say I really dislike external power supplies connected with super thick cables that are hard to connect.  That's what you get here.  Worse, the umbilical is on one side, and the power cord the other.  Yuck.  It means there is no good way to place or display the PS, which completely negates the nice looking chassis the PS is in.  I much prefer onboard power supplies.  I'm sure there is a good technical reason for having an external PS, such as a lower noise floor, less hum (and there was blissfully no hum or noise I could hear even with very efficient headphones).  But that said, I still had a very hard time trying to decide where to put what is a fairly compact amplifier because of the PS.

And then, there is the price.  The fact of the matter is this is a terrific sounding amp with the right headphones, but only fairly efficient headphones need apply, given the somewhat limited power output available (averaging 250 mW).  You can use both high and low impedance headphones, which is great - assuming a reasonable sensitivity.  $2,500 is a LOT of money for a headphone amp.  I know that the cost of goods of the L-2 is very high, and when you see it, you understand why.  The price seems justified in terms of the cost to make the product – but that doesn’t increase the number of people who will buy a $2,500 headphone amp that requires fairly efficient headphones.
 
Final Thoughts

But I understand that there are trade offs. And the fact is that I was VERY tempted to buy one just for my W3000ANV, but I cannot justify the expense.  Pity...I will hate to see it go.  For those who have the money, and want a compact, nice looking, well made headphone amp to use with high end, high-sensitivity headphones, the L-2 would be a very good choice.
 

REVIEW: Meier Audio Corda Classic solid state headphone amp.
 
Introduction
 
My first serious headphone amp was the Meier Audio Corda HA-2 Mk II.  It was something of a revelation to me at the time – I had never heard a headphone amp that sounded as good.  I didn’t have much experience with headphone amps back then, and the HA-2 mk II was a huge cut above anything I had experienced.  The crossfeed was especially important to me as I first got used to headphone listening as a serious alternative to speakers.
 
I’ve probably listened to over 100 headphone amps since then.  Meier has cranked out a pretty steady of very fine headphone amps since that time, including, most recently, the Concerto, which I thought highly of.  The Corda Classic is based on the Concerto, with some feature additions, and some tweaks (like, says Meier, using the nicer and costlier Nichicon FG caps rather than the FW of the Concerto).  The Classic does have selectable two-stage crossfeed, which is a hallmark of the better Meier amps, and often a useful feature.  It also has the subtle bass compensation circuit for the crossfeed, which can be handy regardless of whether one is using crossfeed, to compensate for recordings.
 
Dr. Jan Meier offered to loan me a Classic for review, to which I happily agreed. Most of the time I will not review products that are not already commercially available, and I never review pre-production prototypes. In this case I agreed to review a production unit in advance of the release date, as Meier's reputation is such that I was not concerned that the unit would not come out. [Note to people who are not long-time readers of my reviews - I almost always review only loaner units from manufacturers, although I will occasionally buy units to review.  Such loaner units are provided at no cost to me for the review period, but are NOT "freebies" - following the review I either return them or, on occasion, I will purchase the review loaner]. 
 
 
The Classic, like many solid state amps, outputs significantly more power into low impedance loads than high impedance ones.  Jan provided me the following information:
 

1. Maximum output current: 500 mA / channel
2. Maximum gain factor: 4,9 x (+14 dB)
3. With a source signal of 2V rms the limiting factor normally is the gain factor. Maximum output voltage becomes 9,8 V rms.
4. At 600 Ohm: 160 mW / channel
5. At 300 Ohm: 320 mW / channel
6. At 50 Ohm: 1.9 W / channel
7. At 30 Ohm: 3.2 W / channel

 
As such, I thought it mated very well with the Audeze LCD headphones, The Ultrasone Edition 8, and with the Audio Technica W3000ANV.  It also sounded good with the Beyer T1, which is 600 ohm, but the T1 is VERY efficient.  Something like the 400 ohm AKG K-340 would probably not do well (but I no longer had a pair to try it).  
 
Looks are also “classic” Meier:
 


 
 
Info from manufacturer’s website: http://www.meier-audio.homepage.t-online.de/classic.htm
 
Build quality is very good, with a solid but non-fancy chassis, and, mercifully, an on-board power supply that would make many modern speaker/power amps blush.
 
I auditioned the Classic over several weeks, using the headphones mentioned just above, plus the Ultrasone Edition 8.  I compared it to the Red Wine Audio Audeze Edition with the LCD-3, and to the Trafomatic Experience Head One with the AT, Beyer, and Ultrasone cans.  As always, my comparisons were done by using an SPL meter to match levels to within <1dB, and calibrated at 80 dB A weighted peaks. 
 
 
Sound
 
As with the majority of Meier products I have reviewed, the Corda Classic provided what I felt was essentially neutral, transparent, clean, and generally “out of the way” sound, more or less directly connecting source to headphone, within its power delivery limits.  The real departures from that come when you start to play with the features. 
 
It's a little difficult to describe the soundstaging of a Meier amp that employs crossfeed, and you can subtly change it.  There was no crossfeed setting that gave me the depth or holographic imaging of my Trafomatic or Leben amps, but the soundstage was nonetheless quite convincing.  The soundstage does shift with the two stages of crossfeed, as it takes on better center focus but loses some channel separation.  The effect is actually fairly subtle most of the time, but on some recordings I much prefer the crossfeed on.  The soundstage gains depth and moves out of the head, which is a pleasant effect.
 
The bass contour can also drive you a bit mad…is it better with or without?  Hard to tell.  I generally used it when the crossfeed was on, and not when not, but I actually sometimes preferred to use it regardless.  The nice thing with both of these features is you can always choose not to use either of them, and in this case the Classic is still a very neutral, transparent, and high quality amplifier.
 
I would love to say a lot more about its sound, but there really isn’t that much to say, which is a good thing, really.  The Classic doesn’t have much of its own flavor.  It won’t power crazy-hungry headphones like the Hifiman HE-6, but aside from that, it was revealing enough to allow me to easily hear the difference between some DACs I was comparing while it was here.  I thought it was good enough to be the main amplifier for headphones costing 2-3 times what the Classic itself cost, which makes it something of a bargain.  It did a good job with detail retrieval, and was nicely extended at the frequency extremes. 
 
If I had to pick a few nits, it doesn’t provide quite the level of iron fisted bass control of the LCD-2 and -3 that I get from the RedWineAudio Audeze Edition, and it doesn’t have quite the same extension at the very top of the frequency range, either.  There were also a few times when things seemed to get a little congested on the Classic with the LCD-3, whereas the same piece of music, at the same level-matched volume, did not sound congested on the AE.  And the AE may be just slightly more transparent.  But otherwise, the difference between the two was not that significant driving the Audeze headphones.
 
Driving the Ultrasone Edition 8, the Meier again basically stepped aside sonically.  I thought the Trafomatic Head One was a little more open sounding in the mids, and has the slightly more holographic soundstage.  But remember that the Trafomatic is a significantly more expensive amp.  When keeping that in mind, the Meier did very well indeed.
 
I really wish I still had the Concerto around to compare, but in my Concerto review, I felt that the Concerto could on occasion be just the slightest bit bright.  The Classic seems to have resolved that, as I never heard even the slightest bit of brightness from it.  Nothing stuck out at all in its frequency response. If anything, the Classic is just the tiniest bit warm, but only slightly.  And you can subtly change that with the bass level switch.  So you can really do some nice system matching that way.
 
 
Summary
 
If you want a neutral, clean, transparent solid state headphone amp that performs at a very high level without costing a fortune, the Meier Audio Classic is a very good option, IMO.  I still find that almost all mid-priced solid state headphone amps, for me, lack a little bit of musical realism, compared to what I hear from tube amps.  Many will call this effect a coloration, and perhaps it is, although I think it’s more complex than that. And it could certainly be considered a personal bias of mine (although clearly shared by numerous others).  In any case, the Classic isn’t going to be confused for a tube amp.  I still prefer to listen to headphones through thermionic valves.  If it were MY $700, I would buy something like the WooAudio WA6.
 
But many people don’t want to mess with tubes, and in the under $1K price range, the Classic has a lot going for it.  While not exactly cheap, the Classic does provide good value in terms of sonics, rated output, and features, IMO.  Jan Meier has a deservedly excellent reputation in the head-fi community, and I think the Classic is a good example of why.  Another excellent product overall from the estimable Dr. Meier.
 
 

Introduction
 
Fang from HiFiMan asked me to review the HE-300 headphones.  I have been a big fan of HiFiMan’s planar magnetic headphones.  But the HE-300 are not planars – they are dynamic driver headphones.  While they look similar to the other HiFiMan headphones, their similarity is really only by look – they are MUCH lighter than the planar series.  They are also much more efficient – at 93 dB/1mW@ 1kHz efficiency, and 50 ohms impedance, they can be driven by just about anything (although of course a good quality amp is still going to yield the best results).
 
Structurally, they are identical to the other HiFiMan headphones:
 


 
 
I find them to be quite comfortable overall, although I have a medium sized head - I think on a larger head the clamp might be a bit strong.  I do think the stock cable is too thick and stiff, but the cable is easily replaceable and there is already a fairly robust group of aftermarket cables for the HiFiMan HE series headphones.  I used a Q-Audio cable aftermarket cable with them for part of the review, and I thought it improved the sound slightly, and the ergonomics MASSIVELY.  Of course, it cost about as much as the headphones do…
 
 
The Sound
 
The HE-300 have a very robust sound, with strong and powerful bass, a slightly warm and forward midrange, and a fairly clean and smooth treble.  While they do not break any new ground here, the overall sound is engaging, and enjoyable.  They are definitely not for the detail freak, and if you like a leaner, more treble oriented sound they probably are not the best choice.  The sound worked well for me, though, as I tend to prefer a somewhat warmer, lusher sound and that is what the HE-300 provides.  While they are not the most transparent headphones that I have ever heard, to be sure, they provide a good level of clarity and transparency in their price class.
 
The HE-300 are definitely warmer and bassier than what anyone could consider neutral.  That said, they are what I think many people would call “musical”, or “fun”.  And that’s not to say that they are hopelessly colored by any stretch of the imagination, but they are for sure voiced on the rich side.  There seems to me to be an emphasis in the 80-120 Hz range, and the treble response sounds like it is slightly shelved down.
 
As such, female vocals were well served.  I also greatly enjoyed some Nat King Cole I listened to on reel-to-reel from the HE-300 – in fact I plugged them right into the headphone jack of my Pioneer RT-707 reel deck, which drove the HE-300 incredibly easily and effortlessly.  I also had no trouble driving them with the Meier Corda Classic, the Meier Stepdance2 portable amp, and any of my vintage amps.  They sounded great with the Trafomatic Experience Head One as well, although that is a much more expensive amp that is likely to get paired with the HE-300.
 
Michael McDonald’s terrifically recorded “Motown” sounded great, but there was very clearly some added bass emphasis, and the lower mids were voiced rich.  The impact of this is that the HE-300 never sounds harsh or strident at all.  I think this will appeal to a lot of folks – I get a lot of inquiries about a headphone that’s not bright.  The HE-300 fits that description quite well.  On the other hand, fans of headphones like Audio Technicas should probably look elsewhere.  The HE-300 is not going to be something that people who like a brighter sound will like.
 
A headphone that is voices warm/lush, like the HE-300, can also seem to lack treble detail at times.  If you listen carefully, it doesn’t actually lack detail – they are there, they are just not being pushed at you.  On the flipside, the mids on the HE-300 can be a bit too forward at times, and so on some recordings you can get a little bit too “midrangy” sound.  I felt that this was the case on Peter Frampton’s “Show Me The Way” – his voice was pushed up front father than I know is what’s really on the recording.  This was only occasionally the case, but this is the tradeoff you get at this price point, IMO.  If you want to get a less colored but equally as musical a sound, you have to step up the ladder – to something like HiFiMan’s own HE-500.
 
The soundstage also is pushed out in front quite a bit, as a result of the frequency response curve.  The soundstage is not very deep, but it is quite wide, and image specificity is good.  Again, good performance for the money, but nothing even close to what you get from something like the HE-6/T1/HD-800/LCD-2, etc etc.
 
 
Conclusions
 
Funny how things progress – I’m not the best person to review the HE-300.  My own headphones that I own are significantly upmarket from where the HE-300 plays.  I no longer have any headphones that are in the same price class as the HE-300, which would be best compared to headphones like the Beyer DT880/990, or the Grado 325i, Denon D2000, or the Audio Technica ATH-A900.  All of these are in the same price range as the HE-300.  I have once had all of them, but I don’t anymore, unfortunately.  At least from memory, the HE-300 competes well in this group, albeit with a distinct personality.  It does not stand up competitively to the much more expensive group of cans I currently own, including HiFiMan’s own excellent HE-6, which is one of my references.  But the HE-300 sound very good for the money, IMHO, and I liked the way it sounded as its colorations lean the way I do, and I wouldn’t hesitate to recommend them as a good potential choice in the $250 price class, with the caveats above.  For a warm, rich listen, it fits the bill well.

REVIEW: Schiit Audio “Bifrost” DAC
 
Introduction
 
By now, Schiit probably needs no head-fi introduction, and so I will not be providing one.  I will also not be making any jokes about the name.  Sorry.  That was so last review
 
I had asked to be sent a review loaner of the Bifrost when the announcement was made about its existence.  Schiit was nice enough to oblige – unfortunately it arrived at a very bad time for me at work, and I was able to spend a good amount of time casually listening to it, but not much time really evaluating it, or writing about it.  I have finally been able to do some of that, although this review isn’t going to be quite as complete as I had hoped.
 
For this review I fed the Bifrost either the toslink output of a Pure i20 digital iPod dock, or USB from my Sony Vaio.  The audio out from the Bifrost was in turn sent to either a Meier Corda Classic, a vintage Marantz 2285 receiver, or the Leben CS-300.  Headphones used were the Beyer T1, Audeze LCD-3, Hifiman HE-6, and Audio Technica W3000ANV.  The Marantz also drove B&W N805 speakers, and I spent quite a bit of time listening to the Bifrost via speakers.  I compared the Bifrost briefly to the MHDT Havana, the Audio by Van Alstine Vision Hybrid DAC, the Red Wine Audio Isabellina Pro DAC, and the HRT iStreamer.
 
There is not much to discuss in terms of the operation.  I’m glad the power supply is onboard; I hate wall warts.  Coax, toslink, and USB inputs; single pair analog outputs.  In the traditional Schiit chassis:
 



 
 
The Sound
 
There have been some “robust” discussions lately about headphone FR, and what measurements of them mean in terms of what we hear.  In stark contrast to that is something like a DAC: Any well designed, modern DAC will measure completely flat in the audible domain, and as such, any differences we hear in sonics really cannot be directly attributed to measured frequency response, as the measured frequency response of a modern DAC is, in almost every case, going to look identical to any other DAC.
 
And yet, if you read this or any other audio site or magazine, people clearly hear differences in DACs.  I certainly do. But I cannot point to a frequency response chart and say “this is why it sounds this way”.  Outside of the frequency response, there are things like jitter rejection that can be measured and have an impact on things like transparency.
 
All that said, I do in fact find the Schiit to be very neutral in the frequency domain.  The Bifrost comes across as essentially uncolored.  Nothing jumps out as being out of balance, even over extended listening.  I would say this is what we should expect from a modern, solid state DAC, and the Bifrost delivers it.  I consider this high praise for a DAC. Certainly bass drum and guitar  from Dream Theater’s “On the Backs of Angels” were plenty full and deep, and very subtle percussion on Steely Dan’s “Aja” was easily discerned, so there is good presence at the frequency extremes.
 
The Bifrost does a very good job of detail retrieval – better than I expected, in terms of what I have heard from other DACs in this price range.  It is also very good in terms of being transparent and grain free, although it doesn’t set any benchmarks here versus higher end DACs (about which, more later).  On its own, it comes across as being pretty free from grain, and being very transparent.  I think it performs well for its price class in this regard, and even beat another more expensive but popular DAC in this regard. 
 
The soundstage thrown by the Bifrost was also good, especially in terms of image stability and specificity.  It was not as holographic as my higher end references, nor was it either as deep, or wide.  But again, taken on its own, it performed well.  The very holographic soundstage on the Porcupine Tree song “Stars Die” was very satisfying, and I didn’t feel like I was missing anything via the Bifrost.  It was very well fleshed out, and Steven Wilson’s voice was well defined and centered, versus the much more spread out harmony vocals.
 
 
 
Comparisons
 
I did level-matched comparisons with three DACs, as mentioned above.
 
Let’s get two things out of the way with ease.  First, the Bifrost absolutely stomps the iStreamer.  The iStreamer seems grainy, veiled, threadbare, and thin sounding by comparison.  It’s not even close.  It’s funny, because taken on its own, I always thought the iStreamer was decent enough, but on the comparison to the Bifrost, if does not fare well.  Granted, it’s 40% of the cost of the Bifrost.
 
On the other hand, the Bifrost was noticeably outclassed by both the AVA Vision Hybrid and the RedWineAudio Isabellina Pro DACs.  In this case, the Bifrost is less than 25% of the cost of the either of these DACs, and it shows.  I found the AVA to be better to some degree in every single respect.  More transparent, less apparent edge and grain, better microdetail, better microdynamics, more natural ease in terms of musical flow, better bass slam and extension, and a smoother and more extended treble.  Midrange on the AVA is drop-dead, breathtakingly beautiful without being at all colored – on the Bifrost, the mids sound thin by comparison.  The Isabellina was pretty much the same story.  The Bifrost was a little closer to the performance of the RWA DAC than it was in the case of the AVA, but still, it was clearly not in the same performance league.
 
But again – that is only by direct comparison.  I don’t think of the Bifrost as grainy or thin.  It is just more that way than the higher-end (and at $2K somewhat expensive) AVA and RWA DACs.  It really isn’t a fair comparison, either, especially knowing Schiit has a much more advanced (and expensive) DAC in the works. 
 
 
The comparison to the MHDT Havana was more interesting.  The Havana is NOT neutral sounding.  It’s a NOS DAC with a tube output.  I like the sound, but the sound is, well, kind of “vintage” – warm and woolly.  And boy was this apparent when compared to the Bifrost.  The Schiit DAC sounds MUCH more neutral than the Havana.  And yes, compared to the very warm Havana, the Bifrost sounds thin.  But it also sounded more open and transparent, has better treble detail, and had more apparent midrange resolution.  Frankly, the Bifrost turned me off so much to the Havana that I sold it.  It’s just too colored, in the end.  Pretty sounding, but untruthful.  The Bifrost is more truthful, even if sometimes there is less beauty in the truth.
 
 
Summary
 
So where does that leave the Bifrost?  At its price, it is a very nice piece of kit, and a good value.  I don’t think it is setting any performance benchmarks in absolute terms, but it provides very solid performance at its price point, and I think Schiit has packed a lot of performance in this DAC at $450.  I regret that I no longer had my similarly priced Music Hall to compare it to, but I was not that impressed with the Music Hall (which is why I sold it).  The Bifrost isn’t going to slay a pile of $2K+ DACs anytime soon, but I don’t think that was Schiit’s goal for it.  For a DAC in the $500 price range, it gets the job done very nicely.  While I may have become “spoiled” by my reference DACs, Schiit should be commended for providing a high performance product at this price.  In the current world we live in, a DAC has become the focal point of the majority of music playback systems.  It’s THE source for most people.  Given that, having a good quality DAC like the Bifrost available at this price point is a very good thing. 
 

REVIEW – Audeze LCD-3 planar magnetic headphones
 
Introduction:
 
The announcement was a well-kept secret, and it hit the head-fi community like a ton of bricks.  Audeze was coming out with a new headphone, the LCD-3, which would feature a new driver, new pads, slightly uprated cosmetics, and would cost $1,950 – roughly double what the popular LCD-2 cost.  Explosions ensued.  There were lots of people very upset about the much higher price.  I was intrigued.  I sought out a pair at CanJam, and having liked what I heard in what was admittedly a very difficult environment to judge open headphones, I asked Alex from Audeze if I could get a review pair sent.  He obliged, and here we are.
 
Audeze made huge strides over the 18 months the LCD-2 were in production in terms of improving ergonomics and comfort, and these are all in play in the LCD-3 – much softer leather earpads, leather headband, angled cable exits, etc.  The LCD-3 has a metal cable exit rather than the extruded wood.  I think this is a very wise move.  Not sure it’s a cosmetic improvement, but given that there were quite a few reports of splits in the wood of the LCD-2’s cable junction, I think this was a wise move.
 
Personal opinion: I like dark wood, and I prefer the darker wood of my original LCD-2 over the Zebra-wood of the LCD-3.  The wood finish is nicer on the LCD-3 to be sure, but I like darker wood.  That’s just me, though.  Many will like this look better.  The dark brown leather is VERY nice looking, and matches the grill color well.  Judge for yourself:
 



 
 
As you can see, the LCD-3 comes in a ver nice wood box, and includes some leather conditioner, as well as balanced and unbalanced cables.
 
I think the LCD-3 are much more comfortable than the LCD-2, also, and this is largely due to the MUCH cushier pads.
 
 
Review parameters:
 
Sources uses: RWA Audeze Edition DAC, AVA Vision Hybrid DAC, MHDT Havana DAC, all playing lossless music files.
 
Amps used: RWA Audeze Edition, Leben CS-300, Trafomatic Head One, Meier Audio Corda Classic; Marantz 2285, Pioneer SX-1980, Sansui 9090DB receivers.
 
Headphones compared:  Audeze LCD-2 R1, Sony MDR-R10, Beyerdynamic T1, HifiMan HE-6
 
Cables used: ALO Cain Mail balanced, Q-Audio unbalanced
 
 
Sound:
 
So, before we can possibly tackle the question of value, we have to first decide how the things SOUND.  And there is no doubt that they sound excellent.  But that isn’t good enough.  A high-end headphone must go beyond that.  It was OK for the LCD-2 to sound “just” excellent.  The LCD-3 needs to sound even better – it has to be at the pinnacle of headphone sound to play at this price point.
And, in the opinion of this reviewer, it is indeed.  The LCD-3 has a coherency, transparency and top to bottom consistency of sound that rate it as the very best headphone I have ever heard.
Take just one example – Diana Krall’s “Do Nothing ‘til You Hear From Me” from “Stepping Out”.  The bowed cello solo in the middle is the most lifelike reproduction of a cello I have ever heard.  The stand-up bass is deep and powerful but with a truly astounding level of definition.  And Diana’s vocals are cleanly rendered in a very lifelike way. 
 
That deep bass was very much in evidence again on Mastodon's "The Hunter", by the recent album of the same name.  Bass is as deep and powerful as one could even ask for, and actually manages to best the LCD-2 in terms of definition and taughtness while not giving up any weight.  This is as good as bass performance gets via headphones.  The LCD-3 have no equal that I have ever heard in this regard.
 
Midrange performance was also absolutely first rate.  There is a slight lushness to the mids, I feel - I'm not sure how else to describe it.  I know one head-fier has described the LCD-2 as "creamy".  I am not sure that's the word I would use, but the mids are surely beautiful, while not sounding colored in any way. I think you can see this in the frequency response chart below, there is a small measured dip at the upper end of the midrange, and I think this is what keeps the mids from ever crossing over into overly-bright territory. 
 

 
 
Nonetheless When guitar has bite, the LCD-3's reproduce the bite, but not in a way that's painful - in a way that seems always very natural.  "Cosmic Egg" from the Wolfmother album of the same way evidences this nicely.
 
I think it bears mention that, from the FR chart above, supplied with my review pair, the FR is not markedly different from the LCD-2 FR charts I have seen.  Nonetheless, the LCD-3 are more neutral sounding than the LCD-2.  I liked the LCD-2’s slightly dark tonal balance a lot, but there is none of that in evidence with the LCD-3.  I would definitely not call them “bright” though.  In fact, I found them to be so neutral as to be difficult to get a handle on sometimes.  I started listening to them on my vintage Marantz 2285.  I thought they sounded very good, but thought they were missing something at the top that I was sure I had heard at Can Jam.  So I quickly moved them to the Red Wine Audio Audeze Edition, and there it was – that treble extension that I hadn’t noticed before that the vintage Marantz lacks (probably not surprisingly).  The RWA AE was much more adept as driving the LCD-3 than the Marantz.  The 2285 doesn’t lack at all for power, but doesn’t seem to have the nuance that the AE does.  And the LCD-3 laid this very plain, in no time at all.
 
All that transparency and neutrality isn’t always a universally good thing, though.  There was a degree to which the LCD-2 allowed one to listen to sub-par recordings and not immediately be struck by how poor they are.  Not so with the LCD-3.  The Waterboys “This is the Sea” from the album of the same name came up on my iPod (which goes digitally via the Pure i20 into the RWA AE’s DAC) and I thought “wow that sounds really, really awful” – but that is just how that recording sounds.  It’s sinfully bright, and that is how the LCD-3 rendered it.  Up right after it was Nickel Creek’s “Best of Luck” from “Why Should the Fire Die”, and that sounded TERRIFIC, as I would expect.  All well recorded material sounded really, really good, and in fact, was the best I have ever personally heard from a headphone, including my beloved Sony MDR-R10. 
 
The LCD-3, though, are better than the MDR-R10.  They are more even in frequency response, and just slightly more transparent.  The R-10 have a phenomenal midrange, and so do the LCD-3.  The R-10 have a little peakiness in parts of the treble, though, that I do not hear from the LCD-3.  And the bass on the R-10 is also a little pronounced in the midbass and a little lacking in the very deep bass versus the LCD-3.  I find the LCD-3 to be a remarkably neutral transducer.  I do not hear any obvious frequency-response aberrations with the LCD-3.  In this way it departs from the LCD-2 – the 3 is more neutral sounding to these ears, and this is most germane in the treble.  The LCD-2 featured a shelved-down treble, which I personally liked, but as such it was not flat from 20Hz-20kHz.  The LCD-3 has much less of this in terms of both the measured performance, and even less in terms of what I hear.  And yet, the treble is not aggressive or biting, but VERY pure and sweet.  Again, the LCD-3 will not hide a recording with a nasty treble though.  If it’s there, you will hear it. 
 
And I think that defines the LCD-3 for me.  The combination of a very neutral frequency response and an almost startling transparency are its hallmarks.  The vast majority of the time I enjoyed listening to music through the LCD-3 more than I ever have with headphones.  Alison Krauss’s new record, Paper Airplane, is a terrific recordings, and it sounded just terrific on the LCD-3.  Alison’s vocals were beautiful.  Same for Steven Wilson’s, on “Postcard” from his new and terrifically recorded “Grace For Drowning”.  The song is just haunting, and it sounds beautiful on the LCD-3.  Then again, I have some metal records that are super-aggressive sounding, and the LCD-3 laid them bare.  Such is life.  For those I will probably stick with the LCD-2.  But one cannot blame the messenger!  I know such recordings are harsh.  No surprise the LCD-3 renders them as such.
 
One result of the combination of the neutrality and transparency is an outstanding retreival of detail and resolution.  Other headphones I have heard force detail at you my pushing the mid treble up.  That's not what is happening here.  The resolution is due to the transparency.  This is something I have found in evidence in all planar magnetic headphones (and speakers) I have heard - and it's very much in evidence here.  There are some very subtle percussion elements in Opeth's "Death Whispered a Lullaby" from "Damnation" that I had never really noticed before, but that I was able to hear on the LCD-3.
 
I also spent some time comparing the LCD-3 to the HifiMan HE-6. I find the HE-6 to have just a touch more treble energy than is neutral, although overall I find the HE-6 to be an absolutely outstanding pair of headphones, and I listen to them at work almost daily.  The LCD-3 were just better, in every dimension, IMO.  Which isn’t to take away from the HE-6, but I found the LCD-3 to be more neutral, and just slightly more transparent.
 
I spent the majority of my review time listening to the LCD-3 on the Red Wine Audio Audeze Edition, since I felt that it had made the LCD-2 sound about as good as anything else, and wanted to give the LCD-3 a very clean signal.  I also played them on the Leben CS-300, the Trafomatic Head One, the new and several of my vintage receivers.  I also listened to it on the new Meier Audio Corda Classic, on which they also sounded great (review forthcoming on the Meier).  They sounded great on the Pioneer and Sansui receivers, but not as good on the Marantz, as mentioned above, just because the LCD-3 exposed a treble roll-off on the Marantz I hadn’t been aware of.  The LCD-3 definitely benefit from the best you can give them, but they sounded very good from everything I listened to them on.  
 
So it also was with sources.  The RWA DAC, my MHDT Havana, and my AVA Vision Hybrid DAC all sounded good, and all sounded different. And to a degree I wasn’t quite used to.  It was very easy to pick out the differences.  The LCD-3 will make a good source reviewing tool!  The Havana is the warmest, the RWA the most neutral, and the AVA in the middle.  This was plainly apparent.
 
Lastly, let’s talk about soundstage.  The LCD-3 is excellent in this regard, but in this one area I don’t think it is quite state of the art.  I think the LCD-3 is better than the LCD-2 in this regard, especially in terms of image specificity.  But the R-10 is better in terms of image definition and specificity.  The LCD-3 projects the soundstage out in front of the head somewhat, which I really like – it does NOT feel like the sound is just between your ears, at all.  The width is outstanding, and so is the depth.  But the images are just not quite as well defined as I hear on some other headphones, like the R-10, or even the Beyer T1.  That said, I am not an imaging freak, and I value tonality and transparency higher.  And so for me, the LCD-3 is as good as it gets.  But if soundstage gymnastics are your primary thing, I think I would probably go with something like the HD-800.  The LCD-3 is “merely” excellent in terms of soundstaging ability.
 
 
 
Summary:
 
So, overall, where does that leave us?  I think the LCD-3, as a whole, is the best headphone I have heard.  I have never owned any electrostats, but I have had several pairs for review, and have heard quite a few others, and I prefer the meatier sound of the LCD-3 to any of those.  But again, that’s not a direct, detailed comparison.  Someone else will have to offer that.  However, the LCD-3 is a big improvement over the LCD-2, and handily beats the Beyer T1 (which is a headphone I like a lot).  I prefer the LCD-3 to the HE-6 as well, and even prefer it overall to the MDR-R10.  And folks, that’s saying a mouthful.  Does that make it worth the asking price?  For me, beyond any shadow of a doubt.  But I liked the LCD-2 a great deal as well, and of course, like all reviews, this one is my personal opinion, and nothing more.  Only you, dear reader, can decide that for yourself.  I sure hope you get a chance to hear a pair, though.  I don’t think you will be disappointed.  I am buying the review pair.  No way am I letting these go.

Starting Up
 
Todd The Vinyl Junkie offered me the opportunity to review the latest offering from Apex, the “Arête” headphone amp.  Which of course I jumped at – it looks like a nice design, and I had thought very highly of the Apex Peak I reviewed last year.
 
The Arête is really as much small pre-amp as it is headphone amp.  It has three line inputs and a line output on the rear, as well as the ¼” single-ended headphone out on the front.  The chassis is nice enough looking and well but not over built:
 


 
 
The Arête, by today’s standards, is not a ultra-high-powered headphone amp, although it has plenty of power for the overwhelming majority of headphones.  The published specs are:
 
[size=10.0pt]Max output level into 150 ohms @ 1kHz: 7.4V RMS / 21V P-P / 360mW
Max output level into 33 ohms @ 1kHz:  4.7V RMS / 13V P-P / 670mW
Peak output current: 220mA[/size]
 
(Further information can be found here: https://www.ttvjaudio.com/store/comersus_viewItem.asp?idProduct=717)
 
 
 
[size=10.0pt]The Arête worked well with the Beyer T1, but likely only because the T1 is very, very efficient/sensitive.  It likely isn’t outputting more than 100 mW or so into 600 ohms.  There was plenty of power for the LCD-2, IMHO, but the Arête was not even close to powerful enough to do justice to the HE-6.  They sounded thin and brittle compared to more powerful amps.  The Arête is not going to do well with high impedance headphones unless they are also of reasonably high sensitivity, and ultra-low sensitivity ortho/planar headphones also need not apply.  A headphone of reasonably high sensitivity, like 90 db/mw in the low impedance range, and high 90’s in the high impedances, is likely going to work best, in order to provide nice headroom.  I am a fairly low volume listener, tending to listen mostly in the 70 dBA range – I calibrate my listening levels to 80 dBA peak.[/size]
 
 
Listening Up
 
The primary defining trait of the Arête is one of being very transparent and very neutral – within its power abilities, comes very close to being a straight wire with gain.  It was very easy to discern the differences between sources though a given set of headphones with the Arête.  The sound was unfailingly clean, and never harsh, but neither is there any prettying up of untidy recordings.  In fact, using an iPod on shuffle (via the Pure digital dock and my AVA DAC), the change from one song to another could sometimes be very jarring due to the differences in the recording quality between the tracks.  Nice. If you want a very neutral, straight line reading of your music, with very little editorializing and good clarity, the Arête is a good choice.  But don’t be upset if bad recordings sound…well…bad.  Don’t shoot the messenger!
 
On the flipside, good recordings were highly enjoyable.  Listening to Joanna Newsom’s “Cosmia” from “Ys” was an absolute pleasure.  The very lush strings and Newsom’s plucked harp were set in contrast to her squeaky but very emotive soprano – exactly as they should be.  It was super enjoyable.
 
The Arete also delivered all of the power of Yes at full throttle in the driving “Madman at the Screens”, the third part of the phenomenal new “Fly From Here” suite.  Chris Squire’s driving bass line which propels the piece was very nimble, well defined, and full via the Arete.
 
The T1 sounded very good with the Arête.  This combination formed a very open window into the music which was very wideband and dynamic.  The soundstage was very wide, deep, and well defined.  It was not quite as deep or holographic as I get from any of my 4 top-tier tube amps, however.  Whether this is real, or a coloration of the tube amps, I cannot be 100% sure, but soundstage depth and 3D realism, while good with the Arête, is not this amps strong suit, and if you are a soundstage freak, I wouldn’t put this amp at the very top of my list.  It’s not a slouch, but there are better in this regard.  I still marginally prefer the T1 with the Woo WA22 and the Trafomatic Experience Head-one, but neither of these amps is as strictly neutral as the Arête (the WA22 is very lush; the Head-One is very close to dead neutral with just a small amount of tube lushness in the midband).
 
With the HD-800 it was a different story, for me personally.  I don’t really like the HD-800’s high-frequency sonic signature, and as such, the Arête’s neutrality laid bare the HD-800’s 6 kHz treble peak, and I didn’t really enjoy the pairing.  I much prefer the HD-800 on the WA22.  The WA-22 is coloring the HD-800, for sure, but in a way that they need to be colored, IMO.
 
The LCD-2, on the other hand, again sounded GREAT with the Arête (I’m talking here about “rev-1” LCD-2’s).  The Arête seemed up to the job of powering them with no real problems.  The combo here did a very fine job, and I think the pairing is synergistic.  This would be a fine SS amp choice for LCD-2 owners.  The clean and neutral presentation benefitted the LCD-2, which themselves are very clean and neutral.  Since the LCD-2 have a remarkably flat response aside from a slightly shelved-down treble, they have nothing to “hide”, and the Arête lets you enjoy their presentation unfettered.   Songs like “Blackest Eyes” from Porcupine Tree’s “In Absentia” which feature both melodic and frenetic sequences were very well served.    Ditto the Ultrasone Edition 8 and JVC DX-1000 – the amps neutrality served these headphone very well, and I enjoyed them both very much with the Arête. 
 
Unfortunately I did not have another well known stand-alone solid-state headphone amp with which to directly compare the Arête.  The Arête delivered competitive (though a bit different) sound to my Trafomatic Head-One tube headphone amp, which is similarly priced to the Arête with Volcano (see below).    I don’t believe in making “value” judgments about products beyond comparing other products of similar price, and based on that, the Arête does seem competitively priced.  For many, $1,500 for the Arête/Volcano is a lot of money to spend on a headphone amp, and you can get excellent performance that is very close to this level from amps half this price.  Nonetheless, the Arête delivers a competitive performance in its price class, IMO.
 
 
Powering Up
 
I received the Arête with the standard power supply, and the “Volcano” option.  ALL of my comments about the sound made above were with the Volcano.  I tried the Arête with the stock PS, but the sound with the Volcano was significantly better.  While the Arête is still a nice amp with the stock PS, I would very strongly encourage people to consider the Arête and Volcano as one “product” (my experience was the same with the Peak).  There is a definite increase in the sense of dynamic ease as well as the transparency.
 
 
Summing Up
 
The Arête provided a very clean, clear, open, and neutral sound.  It’s not a massive powerhouse, nor is it an amp to be used if you want to “pretty up” the sound.  But if you want an amp that will give you a wide open window to the music you are feeding it, and you have reasonably efficient headphones (or maybe better stated, you are not trying to use it with the most power-hungry of headphones), the Arête will deliver the sonic goods.  With those characteristics in mind, I can recommend it.  For me personally, it wasn’t a great sonic match for the HD-800, and wasn’t powerful enough for the crazy-power-hungry HifiMan HE-6.  But with the T1, Ultrasone Edition 8, JVC DX-1000, and LCD-2 it was terrific.

Mini-review: HiFiMan HE-500 Planar-Magnetic Headphones
 
Fang from Head-Direct was kind enough to loan me a pair of HE-500 for review.  The HE-500 are billed as a more efficient version of the HE-6, although there are some other differences, both in design and in sonics.  They are also a little different looking, in that the casing is a very nice gun-metal grey:
 


 
 
Taken on its own, the HE-500 are really an exceptionally good headphone.  While they still require a somewhat powerful headphone amp, I was able to drive them with no problem from the Woo WA2, WA6, Trafomatic Head One, Decware Mini-Torri, Musical Paradise MP-301 mk2, and Leben CS300XS, all without any issues. 
 
The sound overall embodied the principle qualities I have come to love from Planar headphones - a very transparent, open, and smooth sound, that is free from the graininess that is present on even the finest of dynamic driver headphones, with the lone exception of the Sony R10.  The mids especially have a transparency that is very beguiling.  The HE-500 are very smooth sounding as well - in some ways they have the smoothest of all of the HiFiMan planars, especially in the treble.  The treble is very smooth, clean, and unfatiguing.  The mids, as mentioned, are very smooth and open, and sound very uncolored.  The bass is full, and fairly tight, with just a touch of mid-upper bass warmth.  Overall the sonic picture is quite neutral, with perhaps just a very small amount of warmth - not a bad place to be for many users.  The soundstage has very good image specificity, and depth is excellent, although it is not as wide as the very best.
 
All forms of music were well served, but I especially enjoyed the new CD by Alison Krauss and Union Station, which arrived about the same time as the HE-500.  Alison's delicate soprano was beautifully and accurately delivered, and the string plucking and tone were excellent.  The HE-500 also had no problem keeping up with very fast metal like Symphony X's "Sea of Lies", or complex prog-rock like in King Crimson's "Red".
 
Versus the HE-6, assuming one is using a powerful enough amp to drive them, I find the HE-6 to be just slightly more transparent.  Bass is slightly deeper, and slightly better defined.  The mids were just a very small amount drier, and the treble is just slightly more pronounced and seemingly extended, without being in any way edgy (although the HE-6 treble CAN be edgy without proper amplification).  If one already owns a VERY powerful amp, the HE-6 provide better absolute performance than the HE-500, IMO.  However, they are $300 more expensive, and they have much more stringent amplification requirements to achieve these results.
 
Compared to the LCD-2, again I very slightly prefer the LCD-2, as I find them to offer a slightly more natural sound (although the HE-500 are still excellent in that regard), and very slightly more nuanced. The LCD-2 are also just slightly more efficient than the HE-500.  But the fact is, I could live very happily with any of these three Planar headphones, and I prefer ALL three of them to any Dynamic headphone currently available.  The HE-500 easily outperform the HD800, Beyer T1, Rudi Chroma MD-1, Denon D7000, Ultrasone Edition 10 or 8.  And given the HE-500's price, they have to be considered a bargain, as far as high-end headphones go.
 
 

REVIEW: Musical Paradise MP-301 MK2 vacuum tube integrated amp
 
Introduction/Overview
 
I received a review loaner of the MP-301 Mk 2 from Garry at Musical Paradise in Canada.  I had a good experience previously with the original MP-301, and had reviewed it favorably a couple years ago.  I was anxious to try the improved MP-301 Mk 2, for several reasons:
 

• It has a switch between speakers and headphones, an important feature which the original lacked;

• It had two inputs, with a switch;

• It uses 6SJ7 driver tubes, which I have a lot of nice NOS varieties I got from the time I owned the Darkvoice 337;

• I liked the look of the amp from the prototype pics I saw.  Here are some pics I took:

 




 
 
The MP-301 Mk2 is all pentode – two power pentodes (6L6, EL34, or KT-66) and two sharp-cutoff pentodes for the driver tubes (6SJ7, 6SK7, or 6SD7).  Garry advised me that the MP-301 Mk 2 is designed primarily as a speaker amp, and asked me to test it with speakers, which I did, as you will read below.  That said, I review products mainly on head-fi, and so the focus of this review was on headphone use.
 
The MP-301 Mk 2 is designed in Canada, but build in China.  This does help keep the costs down.  The amp is output transformer coupled, which means that it delivers more power to low impedance headphones than a typical OTL (output transformerless) tube amp will.  MP provided the following specs for the headphone output:
 
output power (True RMS) for headphone is 1.53W for 32ohm, 0.79W for 62ohm, 0.16W for 300ohm, and 80mW for 600ohm
 
So the amp provides the most output for lower impedance headphones.  However, as you will read below, it is most prone to some potential hum with lower impedance headphones.  If you plan to use low impedance headphones (below 50 ohm), there is a mod that Musical Paradise will do to better accommodate low impedance headphones.  Future versions will apparently offer a switch for headphones of different impedance.
 
For those thinking of using the MP-301 Mk 2 to drive headphones like the HE-6 or AKG K1000 from the speaker taps, I was told by Garry from Musical Paradise NOT to connect any headphones in this manner.  He said this could cause output transformer damage, since the transformers are not designed for such high impedances.  So I did not try that.
 
One other thing I think should have been included is a power on LED.  Other than the switch and the glow of the tubes (which in spite of my clever pics don’t really glow all that brightly), there is no indication that the amp is on. 
 
 
Adventures in Tube Rolling
 
Those who know me or who have read my other reviews know I almost never use stock Chinese, Russian, or any current production tubes even for one second.  I have a large collection of NOS tubes and almost always find these to be better. 
 
So I first powered up the amp with my best shot – Mullard EL34 power tubes and Tung-Sol mesh-shield 6SJ7GT’s from WWII.  Unfortunately, I was greeted with an unacceptable level of hum.  I decided to run the amp in for a few days in hopes this would go away.  But it did not.  Low impedance headphones were worse than higher ones.  The hum was barely noticeable with 600 ohm Beyers (but the MP301mk2 is not really a good choice for 600 ohm Beyers due to the relatively low power delivery at that impedance).  It was a little too audible with the LCD-2.  It was totally unacceptable with the Edition 8. 
 
I tried two other sets of Tung-Sol 6SJ7GT, but no change.  I then tried some Sylvania 6SJ7WGT, and they were a little better, but not better enough.  I then gave up on the EL34’s, and swapped in some Tung-Sol 6L6WGB power tubes, but that did not really do much to reduce the hum.   
 
So I ordered a pair of 6SK7GT's, which Garry from Musical Paradise suggested might have less hum than the 6SJ7GT. I put these in, and I still had just a bit more hum with headphones even with the Sylvania's than I really find acceptable, although otherwise the sound was excellent.  So I continued on.   I put the stock driver tubes in, and there was almost no hum with any headphones. This was using NOS Tung-Sol 6L6 output tubes.
 
Encouraged, I tried another pair of really nice NOS 6SJ7GTs - Raytheon Bantals. Success! Another pair of totally quiet tubes. I'm not sure exactly why some of the NOS driver tubes I tried would be quiet - two of the pairs I used had been used in my DV337 when I had it and were completely silent in it. But at least the stock driver tubes work perfectly, and so do the Raytheons. The stock preamp tubes are really pretty decent sounding. The Raytheon 6SJ7GT's I am using now are a little smoother in the treble, and just a little warmer overall. But given the difficulties in getting quiet NOS preamp tubes, I think my recommendation to people would be to upgrade the power tubes, leave the stock preamp tubes in there, and see how you like the sound, and if you like it, leave it! The stock preamp tubes with the NOS Tung-Sol 6L6WGB tubes I put in sounded very good.

It’s still a bit disappointing that three pairs of NOS 6SJ7 and one pair of 6SK7 tubes all hummed unacceptably. Also, one of the stock power tubes I received was bad - loose base, and was crackling badly when used. There was, however, no hum with the stock power tubes either, confirming my suspicion that the driver tubes are what are prone to hum problems. The power tubes had NO impact on the hum issue at all. Changing them did NOT help, at all. ONLY changing the preamp tubes helped. So of multiple pairs of preamp tubes, only the stock tubes and one pair of Raytheon 6SJ7GTs were quiet.  And I do not believe there is any magic to the Raytheons – it was just luck, I think, that this pair was quiet in the MP-301 Mk2.  I'm not exactly sure why, although I do know that this type of sharp-cutoff pentode is prone to hum in audio applications. Too bad - it's a great sounding tube, but given the hum problems, it may not be an ideal choice in a low power audio amp.

Anyway, with my NOS 6L6 tubes and the either the stock preamp tubes or the Raytheon 6SJ7GT’s, the MP 301 mk2 worked well and sounded good.  I could finally get to the review!
 
 
Sound - Headphones
 
Again, the MP-301 Mk2 isn't designed primarily to be a headphone amp - it's more designed as a speaker amp with the convenience of headphone use. But with the right tubes and headphones, it's a very good sounding headphone amp, especially for the money.
 
The MP-301 Mk2 was actually at its best driving the LCD-2 and the new Hifi-Man HE-500.  It has enough power to deliver all the volume I needed with either of these headphones.  It’s putting out about 1.5 W into the HE-500’s 38 ohms, and about 1W at the LCD-2’s impedance.  Given their sensitivity rating, that is plenty of juice for all but the nuttiest headbangers.  You can forget about using the HE-6 with these though – not enough power for those.  The Beyer T1 and HD800 also sounded pretty decent, but the only reason the T1 worked well is that they are super-efficient.  The MP-301 Mk2 only musters 80 mW into 600 ohms. 
 
I really liked the sound with any of these though, and the basics of what the MP-301 Mk2 offered with headphones sonically was pretty similar.  The overall sonic picture is one of a soundstage that is well defined, with good lateral placement, but that is deeper than it is wide.  The midrange is definitely vacuum tube based.  The 6L6 has a well-deserved reputation as being good sounding for being a fairly powerful tube, and I found the all-important midband to be generally clean, just a bit in the rich side, and perhaps just a little but forward in the lower mids at times. 
 
Female vocals were very good – in fact ALL vocals were very good.  Strings sounded sweet but had the right amount of both body and string.  I especially enjoyed some of my favorite female-fronted goth metal with the MP-301 Mk2.  The new album from Sirenia, “The Enigma of Life”, was highly enjoyable, and Ailyn’s sometimes delicate and sometimes powerful vocals were well presented.  I also enjoyed the wonderful new recording from Alison Krauss and Untion Station, Paper Airplane, quite a bit on the MP-301 Mk2, for the same reasons.  Diana Krall’s sultry semi-hushed vocals on “Black Crow” from “The Girl In The Other Room” were just beautifully rendered, and was the attack of her piano.  In fact, this excellent recording was well rendered in general by the combination of the MP 301 Mk2 and the HifiMan HE-500.  Also, the stunning performance of “Loser” from the recent Gateful Dead release of their 1989 concert in Philadelphia “Crimson, White, and Indigo” was very well rendered, with both Garcia’s voice and guitar sounding exactly as they should.
 
Bass performance was good.  Bass weight in the mid and upper bass was pleasing.  The MP-301 Mk2 does not plumb the absolute depths, and bass is a little looser than the best, but like other pentode/transformer coupled tube amps I have, it is better than many OTL amps in terms of bass definition.  Still, if you are a bass texture freak, this isn’t the amp for you.  There was plenty of weight to Phil Lesh’s bass on the aforementioned “Loser”, but I know that recording super-well, and there was some depth and definition missing.
 
Same up top.  The treble is sweet, and never harsh at all, but compared to better amps, it lacks a little detail and extension.  I preferred the MP-301 Mk2 with the HifiMan he-500 over the LCD02 for this reason – the LCD-2 plus the MP-301 Mk2 at times could seem a little dark.  Many know I do NOT find the LCD-2 to be dark sounding on its own, but when the amp is a little dark, which the MP-301 Mk2 is, IMO, then the LCD-2 will not “cover” for this.
 
I spent a little time comparing the MP-301 Mk2 to the WooAudio WA6, which is the closest amp I current own to the MP-301 Mk2 in terms of price and topology.  In terms of its use as a headphone amp, the MP-301 Mk2 is not really competitive to the WA6.  Which is NOT to say the MP-301 Mk2 isn’t good, but the WA6 is simply much better as a headphone amp.  As well it should be – the WA6 will not drive speakers, and is more than 2 times the price of the MP-301 Mk2!  Still, treble and bass extension and definition on the WA6 were audibly better, no doubt, as was soundstage width.  Still, let’s recall that the MP-301 Mk2 is $260!  It’s really important to keep that in mind when considering the above.  What the MP-301 Mk2 delivers for $260 is impressive, indeed.
 
 
Sound – Speakers
 
I had given my original version MP-301 to my son to drive a pair of B&W DM601 S2 bookshelf speakers.  I thought that sounded great.  He wanted something with remote and iPod integration, though, so I bought him a Cambridge Audio integrated unit.  I dropped the MP-301 Mk2 back into that system for a little bake-off. 
 
First of all, the MP-301 Mk2 had no problem driving the DM601’s to nice levels in my son’s bedroom.  Earsplitting, no, but plenty loud enough for my wife to yell at me to turn it down!  I noticed very little hum with speakers, and even then only with my head fairly close to the speaker, and of course no one actually uses speakers like that
 
The sound with speakers was basically as I described above – the overall sonic signature wasn’t different.  The sound was very pleasing overall, and really very good for the price.  Kind of amazing, actually.  I preferred the sound from the Musical Paradise over the Cambridge Audio One+, which offers more features but is more than twice the price of the MP-301 Mk2.  There are limits to how much volume you can get out of the MP-301 Mk2 with speakers, and I wouldn’t even try to use it with tower speakers in a big family room.  But with moderately efficient bookshelf speakers in a modest sized room, the sound was quite good, and definitely competitive with other speaker amplification options for such applications.
 
 
Conclusions
 
I have always said that reviewing budget products is tough.  It’s relatively easy to pick out and focus on their problems, and not spend enough time on their strengths.  It’s no different with the MP-301 Mk2.  Musical Paradise has worked hard here to keep the cost of this product down, and given its price, it sounds very, very good.  It’s actually great that you can get this much good sound for this price, and from speakers or headphones!
 
That said, there are some concerns, for sure - it's unfortunate that it seems to be very sensitive to the tubes used in it.  This was kind of frustrating, although one can avoid such issues by just using the stock tubes.  That said, several users also have received bad power tubes (me included).  And while it is quietest with high impedance headphones, it delivers the least power to these.  Being transformer coupled should enable it to handle lower impedance loads, but it has the most hum issues with these.  And the fit and finish was nice in some ways, but only fair in others (the lettering/stenciling on mine was somewhat poor).
Still…you cannot expect perfection for this price.  That you don’t get it should come as no surprise.  You do get an amp that sounds quite good, and will do a decent job with many speakers and headphones (though not all). 
 
So…do I recommend the MP-301 Mk2?  Sure I do.  I recommend it for people on a budget, who have moderately efficient bookshelf speakers in a modest sized room, and/or headphones between 40 and 300 ohms, and who are not dying to spend all their time and money tube rolling.  In that context, the MP 301 Mk2 is a stone cold bargain, and a fine little amp.
 

Now that I have spent time comparing the HE-6, LCD-2, Edition 10, T1, and HD800, I thought the time was right to put down a few thoughts on the HE-6, which are, when properly amped, a TERRIFIC headphone.
 

 
The HE-6 have incredibly transparency, and a very wide-bandwidth delivery that is remarkably even and smooth.  While they have just a slightly lively treble, this is more an elevation overall than a single peak, and their treble performance sets them apart from the HD800 and Edition 10, which have more issues in the treble.  The bass is just slightly less in weight and quality than the LCD-2, but nonetheless outstanding.  And the mids are just unbelievably transparent.
 
While the HE-6 can sound phenomenal, they won't unless they have a lot of power.  The best they ever sounded to me was hooked up to the speaker outputs of my Leben CS300XS, which is a 15 wpc amp.  There is no doubt that the HE-6 like a good strong amp.  But given good, plentiful power, they well deliver an amazing sonic performance for the money. 
 
To elaborate on the amplification story - the fairly low efficiency really does mean a pretty powerful amp is needed to make them come alive.  The WA6 was insufficient.  The Leben CS300XS was better (from its headphone out), but the Decware Mini-Torri was even better (since using its headphone out is basically 100% the same as using its speaker outs).  Via the Decware, the HE-6 can really be allowed to swing, and swing they do.  I later tried driving the HE-6 from the SPEAKER outs of the Leben, and this was better still.  This gave the HE-6 a better sense of ease and dynamics.
 
Even later, I used a vintage Marantz 75 wpc Receiver for the HE-6, and this was also excellent.  Much better than any of my other headphone amps except the Leben and Decware, which are really speaker amps themselves.  A speaker amp really is the best choice for the HE-6, and you can get a pretty good one without spending huge amounts of money.
 
I spent some VERY enjoyable time with the HE-6 played via the Fisher KX-100. For those unfamiliar, the KX-100 is a 60's vintage all tube integrated amp using 7868 pentode power tubes in a push-pull, transformer coupled configuration, and with speakers rated about 25 wpc. The headphone Jack is driven off the output transformer, presumably using a 32 ohm secondary winding, but I am not sure of that.The Fisher is has a classic tube sound - warm, romantic, and lush, with a plump bass and a slightly shelved down treble, with beautiful sounding mids. This works better with some headphones than others, but it was awesome with the HE-6, which are, on their own, very neutral, with just a slight treble tilt. The combination was just gorgeous - surely not the most neutral sound there is, but wonderful to listen to.Power wise it was fine. On the Fisher's own scale of 1-10, I got my normal listening level at 6.5, which is where I typically listen to speakers on the Fisher (which I use primarily as a speaker amp). The results were highly enjoyable.
 
I also tried the Meier Concerto.  At reasonable levels, the Concerto sounded very, very good with the HE-6.  I also spent some time today with the HE-6 and an inexpensive Class D speaker/headphone amp, which outputs 10W into 8 ohms, and the Concerto was so much better with the HE-6 that it was almost laughable.  I stopped listening to the Class D amp after about 20 minutes.  It really did not sound good, and just slightly above my normal listening levels, it started to distort badly.
 
For whatever reason, the Concerto does not ever distort.  I get to full rotation of the volume control, in high gain mode, and there is no distortion or clipping, and that is a level quite a bit louder than I would normally listen at, although I know from experience that it is a lower level than some people like (although those people are taking chances with hearing damage). 
 
So since there was not a problem with clipping or distortion, I tried to listen for other more subtle signs of stress, which at my normal listening levels, I really could not detect.  Overall the sound was quite engaging, smooth, and nicely nuanced.  I got nice punch in the bass, and very natural mids, with less glare in the treble than I have heard with some other amps that I know were straining.  The treble was actually really nice in combination.
 
I definitely would not recommend that people who own the HE-6 buy a Concerto to use as the main amp for them, as there is no doubt a limit to the Concerto's ability to drive them.  But if your main amp was already a Concerto, and you wanted to get HE-6's with the idea of using them with the Concerto to drive them at least for some not insignificant period of time, I wouldn't hold back.  The combination was certainly serviceable - it was actually quite enjoyable, within its volume limitations.  But the HE-6 definitely sound much better with more power than this, and will reward the listener with even better sound with more power. 
 
So as you can see, while I preferred some really powerful amps, the HE-6 are a superb headphone even driven by some pretty "normal" headphone amps.  And how much power you really need is also highly dependent on what kind of listening levels you want to achieve.  I realized once again when a friend of mine was over that I listen to headphones at much lower levels than many people do.  The last two people who have come over here to check out headphones listened at levels I personally couldn't stand.  So how much power you need absolutely depends on how much volume you're going to demand.
 
Of all of the current production high-end headphones I own, only the LCD-2 slightly nudges out the HE-6 overall for me, although for someone who likes a little more treble energy, I am certain they would prefer the HE-6.  And for me the HE-6 are still terrifically good, when powered right.  An impressive headphone.
 
It's funny - when I got the Beyer T1's, I was thrilled - they were so much better than any of the other headphones I owned.  But then along came the LCD-2, and now the HE-6, and my T1's are not getting very much head time.  The HE-6 are better than the T1, IMO.  They are more open sounding, and seem to put less in between the music and the listener than the T1, which is a good thing.
 
But in any case, the HE-6 have been really impressive.  With the right amp, they have are highly transparent, have great dynamic capability, and a very wideband neutrality.  I can tell they will be a staple of my collection for a long time to come.

This is not a full review, just a rating and a few comments.  I bought my WA2 used, and was really surprised how good it is.  The WA2 is among the better headphone amps available.  It actually surprises me that it's not even more popular than it is.
 
The WA2 has some pretty impressive power delivery, and it works wonders with high-impedance cans like the Beyerdynamic T1, and is also remarkably good with the Audeze LCD-2 and HifiMan HE-5LE.  Only very low impedance dynamic drivers, where the damping factor could be an issue, and not in the WA2's sweet spot.  But with the T1, the WA2 is absolutely stunning. 
 
The WA2 is an outstanding headphone amp, and the fact that it has multiple inputs adds to the string value. 
 

This is NOT a full review, but really just a rating.  I have owned The Stealth for quite a while.  While one of Ray's older models, it still provides outstanding sound for medium-high impedance headphones, and works exceptionally well as a preamp.  It provides 90% of the sound quality as my three times as expensive Cary SLP-05 as a preamp.  As a headphone amp, it's a little on the warm and dark side, but still with excellent detail.  I prefer using the 12BH7 as the input tube, for a little livelier sound.
 
If you need a multi-input preamp with a excellent headphone out, want lots of tube-rolling options, and have headphones of medium or high impedance, then this is an amp worthy of consideration.  If you don't need the preamp features, though, it's too expensive for the performance of the headphone amp alone.
 

 

REVIEW – Schiit Audio Valhalla Tube Headphone Amplifier

 
 
What Sort of Schiit is This?
 
I read, as did many of you, the head-fi threads about the very popular and attractively priced Schiit Asgard.  But to be quite candid, I personally had about as much interest in an inexpensive solid-state headphone amp as I did in weeding behind my garage.  As such, I have never heard the Asgard.
 
Good thing I read those threads anyway, though, since I learned from them that Schiit was coming out with an inexpensive TUBE headphone amplifier.  Now THAT I was interested in.  I emailed Schiit’s Co-Founder, Jason Stoddard, and he agreed to send me a Valhalla loaner to review. 
 
When the box arrived, I actually burst out laughing – I was surprised how small the box was.  Could a real tube amp actually be in there?  The packaging was really nice, though.  The tubes were in their own sub-box, in custom foam.  Amazingly, a nice 1/8” – RCA cable was included, although honestly I think they could have skipped that and saved the money.  A ¼” to 1/8” adapter was also included, which makes a little more sense, but again, given almost all headphones come with one, not sure that was needed, either.  But hey, it was thoughtful!
 
Installing the tubes was super-simple (but of course it’s something I have done hundreds of times in other amps).  Not much else to the set-up.  I used the Valhalla primarily with the Beyer T1’s.  The Valhalla is output transformerless, and while Schiit doesn’t specify an output impedance, and while they specify it working with headphones as low as 32 ohms, typically, for dynamic headphones, anything below 150 ohms or so is going to be a bit of a crapshoot in terms of good synergy, due to the lack of damping factor you can have when the headphone impedance is near to or lower than the output impedance of the amp.  As I learned recently, planar headphones like the LCD-2 are not affected by damping factor in this way, but nonetheless they require a lot of current, which a small OTL amp like the Valhalla isn’t likely to be able to crank out.  And indeed, Schiit does not really endorse the use of the Valhalla with the LCD-2.  On the other hand, the Beyer T1, being 600 ohms, should be a great match on paper, and, as you will see, was in practice as well.
 
 

 

 

 
 
The Valhalla appears generally to be well made.  Let’s recall, we’re talking about a made in the USA tube amp for $349.  That’s pretty impressive.  The Valhalla is nice looking.  While the fit and finish was not 100% perfect, it was darned close.  And the amp was astonishingly silent – absolutely no hum or noise I could hear even with the volume control at full rotation – this was a real surprise to me.  I was impressed.
 
 
That’s some GOOOOOD Schiit
 
That said, when I first plugged it in and put on some music, I was not too impressed.  It sounded bright and veiled.  However, I know that TUBES need a good few hours of burn-in for sure, let alone amps.  So I played music on it for about 12 hours, and then tried again.  Things were quite different.  The sound was already really very good after this period.  By 20 hours, it had basically settled in.  It might have improved a little more as I went along, but I wouldn’t swear to that.  Certainly I noticed no change past 50 hours or so.
 
Here is what the Valhalla is: an outstanding sounding headphone amp for the money.  It’s dynamic, essentially transparent, and essentially neutral.  There may be a very slight top end reticence, and a very slight lack of power at the very bottom, but these were not all that noticeable really.  In general the sound was engaging, enjoyable, and was better than the majority of the under $400 tube amps I have heard.  It’s also dead quiet – I had no hum or hiss, or microphonics issues from the tubes used.   This was a pleasant surprise.
 
What the Valhalla is not: a “tubey”, “syrupy”, or overly-lush amp.  Far from it.  It has just a dash of tube romance in the mids – just enough to believe that the tubes are really in the circuit – but that’s about the extent of that.  If you’re looking to warm up your icy headphones or source with the Valhalla, I recommend that you save your money.  It will not do that for you.  That just isn’t what the Valhalla is about.  The Valhalla is a darned good headphone amp for the $349 asking price, regardless of whether we are discussing tube versus solid state.  It will, also, drive high-impedance headphones very well, which many inexpensive solid-state amps might struggle with (whereas it’s not ideal for low-sensitivity, low-impedance headphones).
 
What it also is not is a “giant killer”.  While I think it’s an excellent amp for the money, it does not sound as good as the more expensive tube amps I have, all of which outperform the Valhalla.  This is no great surprise, not is it in any way a negative to the Valhalla.  But nonetheless, it would be a mistake to buy the Valhalla hoping it outperforms $1K tube amps, or even $600 tube amps – it does not, IMO.
 
 
 
Now the details.  The mids had just a touch of tube lushness, which was nice, and in general were very well rendered.  Vocals are clean, clear, and present.   Electric guitars had the right crunch and tone.  The amp isn’t overly plump, but it absolutely never sounds threadbare or thin, which is simply the case with what I hear from a lot of solid state amps in this price range.  The performance in the mids is nowhere near what I get from something like the WooAudio WA2, Decware Mini-Torii, or the Leben CS300X, but those amps are 3-10 times the price of the Valhalla!  For the asking price the mids are good.  Compared to the WA2, they sound a little cloudy and opaque.  Maybe more than a little, actually.  But again, that’s not really a fair comparison.  Taken on its own, the Valhalla has a very pleasant midband.
 
After break in, the bass performance was pretty impressive.  The powerful kick-drum on “Bladecatcher” from Mastodon’s “Blood Mountain” was rendered full force, and was nice and tight.  It has to be full to be heard over the absolute chaos that the rest of the song doles out, and the Valhalla pulled this off.  The Valhalla was also revealing enough that I could hear the distortion that is present in this recording due to overmodulation.  Don’t blame the messenger!  It’s on the record.  The fat bass lines from Phil Lesh in “Lazy Lightning” from The Grateful Dead’s “Dead Set” were also meaty and Phull.  Phil-bombs will be plenty powerful on the Schiit (sorry, just can’t help it…)
 
The treble is a touch on the sweet side, but again, not much.  It’s nicely detailed, too.  It’s not the absolute last word in clean or transparent up top, but it’s certainly not bad.  Here again, it lacks the nuance and transparency of my more expensive tube amps, but taken on its own it’s very good performance, and especially for the money. 
 
There is also a very slight occasional softening of vocal sibilants, which some people might actually find they really like.  Patricia Barber’s voice on “Late Afternoon and You” from “The Cole Porter Mix” is pretty close mic’d, and via the Valhalla, there was a little less sibilance than is actually on the recording.  So if you are the kind of person who just HATES sibilance, whether the recording contains it or not, the Valhalla is a good choice of HP amp.  It definitely doesn’t emphasize sibilants, and at least in some cases seems to de-emphasize them a little (which of course comes at the expense of having the treble be a little bit on the soft side).  Again, this effect is slight, but it’s there.
 
Soundstaging was generally also quite good, with believable images, and decent dept and width.  This wasn’t really the strong suit of the Valhalla, and the absolutely holographic imaging that I get from my high end tube amps was not in evidence at all with the Valhalla.  One of the reasons I prefer tube amps over their solid-state counterparts, as a general rule, is for the soundstaging – I have only heard really palpable imaging via headphones with the better tube amps.  Given that in general tube amps are really not much different tonally from the majority of SS amps, in spite of what people may want to believe, this imaging ability of great tube amps is one of the things that sets them apart, for me.  Unfortunately, I did not get this from the Valhalla.
 
The one tube amp I had on hand in the same price class as the Valhalla was the J Sound Lab “Headphone” which costs the same exact amount - $350.  The Valhalla is the clear winner, there, however.  The J Sound Lab is a VERY warm, tubey sounding amp.  It colors everything connected to it in that way.  While there a few headphones I like the effect with, in general I find the Valhalla to be the much better sounding amp – more neutral and balanced, and as such easier to match sonically with more headphones.
 
 
No Rolling in this Schiit
 
Schiit designed this amp very specifically for the tubes that are in it.  They believe that for an entry-level tube amp, the benefits of tube-rolling are outweighed by the hassle and expense.  And maybe they are right.  Sure made the review easier!  But just something to be aware of.  I love tube rolling, but I already have a ton of tubes.  For someone who is new to tube amps, this really does kind of simplify things.  If you want to buy an amp and experiment with tweaking the sound by choosing different tubes, you will need to look elsewhere.
 
 
Bottom Line
 
If you want some Schiit, choose based on what headphones you have.  The Valhalla was a delight with the T1.  Many others have reported the Asgard is a delight with orthos and planars like the LCD-2.  So you want to choose your Schiit right, based on what cans will be used.  As long as you pair it with something appropriate, the Valhalla is a whole lot of headphone amp for the money.  Enthusiastically recommended – and in fact, I am buying the review unit – I couldn’t bear the idea of sending it back.  Am I going to start listening to the Valhalla and stop listening to my high-end tube amps?  Ummmmm…No.  But the Valhalla is a great reference point for entry level tube-amp performance, and so I wanted to keep it on hand as a reference.  It’s value is that good.

[size=11pt]Intro[/size]

[size=11pt] [/size]

[size=11pt]I was approached by the Malaysian distributor of Yulong (the ShenZhen YuLong Electronics Co. Ltd of China) about reviewing the D100 DAC/headphone amp.  I had previously given a relatively favorable review to the older and less expensive/ambitious DAH1 Mk II, which was sent by their China Distributor, Audiophile China.  However, I gave a not-so-great review to a different product sent to me by AudiophileChina (not a Yulong product), and AC reacted badly, and so I suppose the fact that the request came from their Malaysian Distributor may not be a co-incidence 

  But these guys were very nice to deal with.[/size]

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[size=11pt]This product already received a VERY thorough, and very favorable, review from Project86: http://www.head-fi.org/forum/thread/499562/review-yulong-d100-dac-amp-reference-quality-with-a-reasonable-price[/size]

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[size=11pt]In spite of the fact that there is no chance that I can top that excellent review, I had already received my loaner, so I thought I would give it a whack anyway.[/size]

[size=11pt] [/size]
[size=11pt]Description[/size]
[size=11pt] [/size]

[size=11pt]The following are the technical details of the D100:[/size]

[size=11pt] [/size]

1. [size=11pt][size=11pt]SNR: >120dB.[/size][/size]

2. [size=11pt][size=11pt]Dynamic Range: 115dB.[/size][/size]

3. [size=11pt][size=11pt]THD+N: <0.0005% at 1KHZ[/size][/size]

4. [size=11pt][size=11pt]Jitter reduction by using ASRC, custom made 1ppm high precision crystal oscillator[/size][/size]

5. [size=11pt][size=11pt]Using TAS1020B USB controller from Ti in adaptive mode. I2S signal then passed to ASRC and then to AD1955 DAC chip. Same THD+N <0.0005% is achieved via USB input, as compared to coaxial, toslink or AES/EBU input.[/size][/size]

6. [size=11pt][size=11pt]110/120V or 220/240 selectable operating voltage. [/size][/size]

7. [size=11pt][size=11pt]Inputs: Optical, Coaxial, USB, AES/EBU Balanced[/size][/size]

8. [size=11pt][size=11pt]Input digital signal format: 32-192 KHz, 16/24 Bit auto detection. USB input supports up to 24Bit 96KHz[/size][/size]

9. [size=11pt][size=11pt]Frequency response: 20-20KHz-0.16dB.[/size][/size]

10. [size=11pt][size=11pt]Power consumption: <20W.[/size][/size]

11. [size=11pt][size=11pt]Headphone output power: 130mW at 300Ohm, and 900mW at 32Ohm (Measured with chassis connect to AC ground)[/size][/size]

12. [size=11pt][size=11pt]Headphone amplifier with selectable sound mode button on the front panel. According to the maker, the default style Mode 1 is “natural and dynamic”, while Mode 2 “will result in a smoother sound, which is suitable for bright headphones, or if you prefer more “dark and smooth” sound”.  In practice, however, I found the two to be VERY similar.[/size][/size]

13. [size=11pt][size=11pt]Two headphone outputs with different impedances: LOW and  HIGH[/size][/size]

14. [size=11pt][size=11pt]Dimensions: 250*180*50mm.[/size][/size]

15. [size=11pt][size=11pt]Net Weight: 1.5Kg[/size][/size]

16. [size=11pt][size=11pt]Packing Size: 300 * 300 * 100mm[/size][/size]

17. [size=11pt][size=11pt]Include in the packaging: This DAC, user manual, USB cable. Power cable[/size][/size]

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[size=11pt][size=11pt]Pics:[/size][/size]

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[size=11pt][size=11pt]Ergonomics and usage[/size][/size]

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[size=11pt][size=11pt]I used the D100 in several ways:[/size][/size]

• [size=11pt][size=11pt]As just a DAC, through my RSA Stealth preamp, with both headphones and my Dynaudio powered monitors:[/size][/size]

• [size=11pt][size=11pt]via the optical input (connected to a Denon CD player for transport)[/size][/size]

• [size=11pt][size=11pt]via the COAX input driven from the coax output of the NuForce uDAC (used just for USB>coax conversion, about which, more later) being fed by my iPad[/size][/size]

• [size=11pt][size=11pt]via USB from my laptop[/size][/size]

• [size=11pt][size=11pt]As a DAC headphone-amp combo.[/size][/size]

[size=11pt] [/size]

[size=11pt][size=11pt]The D100 had no problem playing music from the USB output of my PC.  Unfortunately, it would not work directly from the iPad’s USB accessory, although the Music Hall DAC 25.2 (which I used for comparison) did indeed work this way.  No issue with the coax or optical inputs whatsoever.  It’s nice to have so many inputs. [/size][/size]

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[size=11pt][size=11pt]The front panel display shows the input, and also the sample rate, which is nice.  When synced to a source, the sample rate flickers – which may be a “feature”, but I found it annoying.  But the DAC worked without any problems.[/size][/size]

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[size=11pt][size=11pt]Sound[/size][/size]

 

[size=11pt][size=11pt]The good news is that the D100, as a DAC, provides excellent sound.  From the RCA/Single-ended outputs, it was detailed, nuanced, and robust sounding.  I found the sound to be quite neutral, but not at all bright, fatiguing, or dry.  It was also very transparent.  Small details in the music were easy to pick out, but I never felt like they were being forced at me.  The sound was unfailingly smooth and natural.[/size][/size]

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[size=11pt][size=11pt]Bass was full, weighty, punchy, tight, and deep.  The mids were very clear and clear.  There is no added warmth here – if you want that from your DAC, this isn’t where to get it, although IMHO you should NOT ask your source to warm up the rest of your system.  Sources should be as neutral as possible, IMO, and the D100 is right on in that regard.  The treble is cut from the same cloth – neither dry nor overly sweet – right down the center.  Nice.[/size][/size]

[size=11pt] [/size]

[size=11pt][size=11pt]“The Boy Who Wouldn’t Hoe Corn” from Alison Krauss and Union Station’s “New Favorite” was absolutely natural sounding via the D100 – impressively so.  I ended up using this track to A/B against the Music Hall Dac 25.2, which sells for about the same price as the Yulong, and has the same feature set.  The Yulong was definitely the better DAC.  It was more transparent, and more natural sounding.  The Dac 25.2 sounded grainy in comparison, and seemed to droop at the frequency extremes versus the D100.[/size][/size]

[size=11pt] [/size]

[size=11pt][size=11pt]The D100’s headphone amp section is actually pretty good – also notably better than the Music Hall’s.  It’s nice to have a High-Z and a low-Z output, and I found the D100 was capable of driving all of my big headphones pretty well.  Compared to the Meier Concerto, though, the D100 lacked some nuance, delicacy, and soundstage definition and air.  But for the price, the D100’s headphone amp is quite good, and for anyone interested in an all-in-one, the D100 beats the Music Hall 25.2 for sure in that regard.[/size][/size]

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[size=11pt][size=11pt]Conclusions[/size][/size]

 

[size=11pt][size=11pt]I could go on and on, I guess, but why.  The D100 is a high-resolution, transparent, neutral, very well built DAC, with lots of inputs, SE and balanced outputs, and a pretty good headphone amp capable of driving a wide variety of headphones, for $500.  That’s a pretty seriously good deal for what you get.  It beat its direct competition handily.  In fact, it was so good, I sold the Music Hall, and I bought the review unit of the D100.  It’s a nice upgrade.  Maybe you, too, need a DAC upgrade?  If so, I’d seriously consider the Yulong. [/size][/size]

REVIEW: Meier Audio Stepdance

Jan Meier was kind enough to send me an early production sample of his new Meier Stepdance portable amp.  The Stepdance is the first Meier Portable to use his “Balanced Ground” topology.  It’s designed as a performance-first portable amp, which means it has very few features (for example, Meier’s normal Crossfeed is omitted), and it also uses battery faster than his other amps, again with the goal of providing maximum sonic performance. In my opinion, this goal is achieved for sure.

Info: http://www.meier-audio.homepage.t-online.de/
 


Build Quality: A: Very attractive and sturdy chassis – same other Meier portables.  The amp is very well built, and looks nice.  I subtracted the “+” from the A because I am not fond of the Meier battery door, and I also don’t like the slight rounding of the chassis, as it makes mating with an iPod for portable use a little difficult.  But this is really picking nits.
 
Treble: A+: The treble is smooth, delicate, extended and transparent.  Compared favorably to the very extended but smooth treble of the Qables iQube, and slightly bettered the RSA P51 Mustang.  Small little nuances were registered cleanly, but there was nothing at all aggressive about the highs.  Cymbals are rendered with a smoothness and naturalness that belies the level of extension and detail that is also very much in evidence.

Midrange: A+: Superbly open, transparent, and clean sounding.  The mids were smooth and enjoyable, if just very slightly warm, although there were times I thought I heard a little extra warmth, and times I felt they were nothing short of completely neutral.  In any case the mids were very seductive and natural sounding for sure.  Outstanding for a portable.  Female vocals like Alison Krauss’s on “It Doesn’t Matter” sound terrific without being artificial in any way. 

Bass: A+: Full, punchy, and well defined. As deep as you could hope to get from a portable amp – and impressively so at that.  The very deep bass at the end of Porcupine Tree’s “Russia On Ice” was reproduced in full measure.  Phil Lesh’s “Phil Bomb’s” from the recent “Crimson, White, and Indigo” release were also very meaty, but with outstanding control and definition.  The punchy bass from the MFSL remaster of REM’s “Murmer” was very satisfying, as it was from “Open Car” from Porcupine Tree’s “Arriving Somewhere” live release.
 
Neutrality: A+: The overall sound is unfailingly neutral and natural.  Nothing sticks out at all.  It’s a little less dry than the iQube, and a little less plump than the P51 Mustang – right down the middle.  That’s a good place to be.  To a degree I am not used to in a portable, the StepDance really just provides power, and otherwise gets out of the way completely.  The difference between the iPad’s line out and the line out of the NuForce uDAC were easily discernable.

Soundstaging: A+: Great depth and width both, and a very palpable, well defined image. Truly excellent performance here.   Even without the hallmark Meier Crossfeed, I felt the performance in imaging was at the very top of the class.  Nice holographic presentation of Alison Krauss and Union Station’s live recordings.  The sense of all acoustics during the a-capella “Down In The River To Pray” was so startling that I had to pause the recording to make sure I was really hearing that and not some other sound!  Sure enough, there it was.  Impressive.

Transparency: A+:  Generally a Meier strength, and very much so here as well.  I found no hint of grain or messiness.  Just clean, clear, and open sound.  This makes the Stepdance really seem to provide a higher level of performance than I have come to expect from portable amps. 

So do I think the Stepdance achieves its goal of maximum performance from a Portable?  In spades.  The Stepdance is my new reference Portable Headphone Amp, against which the others will be judged.  It sets the bar very high in what can be done in a headphone amp, and rather than put money into features that many users do not want or need, it puts all the emphasis on sonics.  This is a laudable direction.  Are there trade-offs?  Sure.  It ate through a 9V LITHIUM battery in about a week of heavy use.  If you want a battery-sipper, this isn’t it.  While not huge, it’s far from the smallest and lightest portable amp I’ve ever seen.   But combined with the iPad and the NuForce uDAC (via the uDAC’s RCA outs), the sound from a transportable rig was just unbelievably satisfying. 
 
The Stepdance is slated to cost $350 USD (270 Euro in the EU).  At that price, and given its performance level, I think the Stepdance also sets the current bar on price/performance ratio. 
 
The Stepdance now resides in the top "Level 1" in my rankings: http://www.head-fi.org/forum/thread/214588/review-portable-amp-roundup-37-portable-amps-reviewed-and-compared#post_2585634

I received a V2 version of the Qables iQube from Moon Audio for review.  The V2 adds a USB DAC, and is a little larger than the original iQube.  It also how has a standard mini-USB connector for either charging or USB DAC connection, and the V2 comes with rechargable batteries.  The amp, however, is identical to the V1, which is a good idea, since I thought the iQube V1 was an outstanding portable headphone amp. 
 
The iQube is a very interesting headphone amp. It's a class D amplifier topology. It was the first of its kind as far as I know - a class D portable headphone amp. Class D has at least the potential of being more battery-efficient, and my experience with the iQube was that I did get a very long duty cycle per charge.
 
Sound quality of the iQube as an amp:

Build Quality: A+: Excellent, VERY attractive metal case. I wasn't sure at first about having the jack on the back and the volume control on the front, but I loved it in the end. There is a very slight turn-on tick. But overall, the build quality is among the very, very best, and it's the kind of thing that gives great pride of ownership.  While it's pretty big, it's also fairly light for the size.
Treble: A+: clean, clear, grain-free, extended and transparent. Great air and extension, and very natural. It wasn't too aggressive ever, but it wasn't at all soft or rolled off. I wouldn't use it with super-bright headphones. But this really isn't the iQube doing anything other than being VERY neutral.
Midrange: A: smooth, clean, and open - with amazing see-through type clarity, while being tonally very neutral. There is perhaps just a touch of reticence, but not enough to worry about.
Bass: A: Ultra-deep and powerful, with excellent definition and speed. VERY tight, but not overly generous. Again, Neutral comes to mind.
Neutrality: A+: The new king of Neutrality. Over and over again that's how I thought of it. Easily shows the difference between headphones in a flash. Only the LISA III is in the same league here. While I still love the Meier Move, it has a "sound" moreso than the iQube.
Soundstaging: A-: The soundstage was great, but it wasn't the WORLD's widest. Still, nothing to sneeze at.
Transparency: A: Nothing to take issue with here either. Try as I might to pick up some kind of issue with transparency related to the use of class D, I couldn't. I just loved it.

I have to say, I was HIGHLY impressed by the iQube as a headphone amp. As a USB DAC, I thought it was also very good - and shared the same neutrality as the amp.  The USB DAC did not quite share the same level of transparency as the amp did overall, but compared to other portable USB DACs, it is competitive with the best I have heard, if not better than them (whereas I think the iQube as an amp is among the very, very best portable amps there are).  That said, I was impressed enough with the performance as a USB DAC that I decided to buy a V2 from Drew at Moon after the review was over (and I sold my V1 that I had bought years ago).  The V2 is an outstanding product.  It's expensive, but it sound excellent and works very well.  If you can spend the $$$, and are not put off by the somewhat largish size, the V2 gets my highest recommendation.

[size=10pt]Introduction and Description[/size]
 
[size=10pt]I received a review loaner of the Blossom BLO-0299 from Drew at Moon Audio.  The Blossom is a pretty small-footprint amp (64 x 158 x 212 mm), which is partly possible since it uses an external power supply (about which, more later).  The Blossom is made in Japan, as incorporates a custom Integrated Circuit which the maker claims is better than any discrete-design could be – a pretty bold claim.  The Blossom has balanced inputs and outputs, and 2 gain settings, 0dB and 10dB.  The headphone out jacks are a clever XLR/1/4" TRS combo that allows a single balanced headphone, or a pair of unbalanced headphones to be connected.[/size]
 
[size=10pt]The Blo-0299 is housed in a beautiful wooden chassis, and is very easy on the eyes (unfortunately I accidentally deleted all the pretty pictures I took, so these are the stock photos, but it is a very beautiful amp in person, I assure you):[/size]
 
 

 

 
 
 
[size=10pt]Turns out it’s also very easy on the ears!  But a few things first.  I needed the high-gain setting for the LCD-2, the HifiMan HE-5LE, and the Beyer T1.  Low gain was fine for the JVC DX1000 and the Denon D7000.  I didn’t really notice any difference in sound between them, and the amp was completely silent in operation.[/size]
 
 
[size=10pt]The only balanced headphones I have are the (excellent) HifiMan HE-5LE, so I used them primarily, driven from my Music Hall 25.2 DAC, which is my only current balanced source.  The pairing was actually really terrific.[/size]
 
 
[size=10pt]But first a note about power, and the supply therein.  The Blossom comes with a pretty pedestrian wall-wart, which doesn’t really become a $1,500 amp, IMHO.  Moon audio supplied a beefy looking, $160 Welborne Labs power supply, which certainly inspires more confidence.  I did A/B them, and can’t honestly say I heard a huge difference, but if you’re spending $1,450 on the Blossom, I would go with the Welborne PS as well, for sure.  It did seem to allow for a little greater sense of ease, and slightly greater dynamics, although again, this was not night and day.[/size]
 
 
 
 
[size=10pt]Sound[/size]
 
[size=10pt]Maybe part of the reason for that is that the Blossom is generally endowed well with a sense of ease, and great dynamics.  The amp is also incredibly neutral, without being in any way overly clinical or cold.  But it was essentially without any significant character I could ascribe to it.  If there was any, it was a very slight softness to the treble, and a very slight reticence in the very deepest bass – but there were VERY subtle shadings.  The music simply flowed, incredibly effortlessly, through the Blossom.  And the window to the music was highly, highly transparent.  It was very impressive in this regard.[/size]
 
 
[size=10pt]Tonally, the Blossom was, over and over again, very neutral and natural.  Nothing stuck out at all, and I mean that in the best of ways.  Midrange was highly transparent, and very open, and free of coloration.  Tracey Thorn’s voice on Everything But The Girl’s “Wrong” was very cleanly rendered.  “Good Morning Groovy” by The Kennedys was absolutely breathtaking in via the Blossom – absolutely clean, great rendering of both brother and sister Kenndy’s voices, with clear delineation between them.  So was the deep bass synth on that track.  The double kick-drum on Circa Survive’s “The Difference Between Medicine and Poison is the Dose” was very fast and taught, and the cymbal work was very clean.  On lesser amps, that song can get pretty congested sounding, but it was very clearly reproduced via the Blossom.[/size]
 
 
[size=10pt]The soundstage was also excellent.  The HE-5LE exhibited the largest and best defined soundstage through the Blossom that I have heard with it.  The soundstage was very good, too, with the unbalanced T1 – but not better than the Meier Concerto.  In fact, when run unbalanced, the Blossom is a little less transparent sounding than when balanced (just a little), and a little less dynamic (again, just a little),.  Too bad I didn’t have a balanced T1 or LCD-2 to compare as well, but the net result was that the overall sound of the T1 running unbalanced with the Blossom was not better than with the much less expensive Concerto.  Overall the performance level there was on the same level. In fact, I slightly preferred the T1 with the Meier, although I preferred the LCD-2 with the Blossom.   [/size]
 
 
[size=10pt]And that’s where I ended up.  The Blossom is a terrific amp, no doubt.  If I have a “beef” with the Blossom, it’s that the single-ended performance was not really any better than the half-the-price Concerto.  As such, it’s hard to justify spending the extra money that the Blossom commands over the Concerto UNLESS you 1. Need balanced drive 2. Really value the beautiful aesthetics (and it is a Beautiful Blossom!).   I confirmed this by using the HE-5LE unbalanced - the performance of the Blossom unbalanced was again on par with the Meier Concerto.  On the other hand, used to drive the HE-5LE balanced, the Blossom made the HE-5LE sound as good as I have ever heard it (and that’s saying something!).  Used to drive the T1 or LCD-2 unbalanced, it was certainly very good, but I think it would have some very tough competition price-wise if used that way, and would be harder to recommend unless the buyer placed a high value on the Blossom’s gorgeous aesthetics.  [/size]
 
 
Conclusion
 
[size=10pt]So that's where I end up on the Blossom Blo-0229.  It’s beautiful, compact, neutral as all get-out, and capable of driving even some tough headphones very well.  Driving the HE-5LE balanced, the sound was truly world-class.  But unless you can take advantage of all the Blossom has to offer, meaning using it to drive balanced headphones, it’s not the cheapest date you can get to the prom.  Only you, dear reader, can decide whether the money is well spent; what I can say is that if you decide to, the Blossom will sound terrific.[/size]

The Leben CS300X has made me re-think what's possible from a headphone amp in general, and tube amps in specific.  While it has a highly musical, engaging sound, it's not the least bit tubey or syrupy - in fact it's astonishingly neutral and transparent.  Due to its being push-pull, and transformer-coupled, it works well with a wide variety of headphones.  It drove my LCD-2, DX1000, T1, W1000X, Ed 8, and D7000 all better than I had ever heard before.  It's so good I wish I had one in every room. 
 
Looks nice too:
 

 
The Leben sounds great with the LCD-2 and T1 - I could very happily live with that combination for a long, long time .

What has struck me about the Leben is that it seems to work well with all the headphones I own - regardless of impedance. But what's been really beguiling me is how great it is with the low-impedance Denons. I've absolutely never heard the Denons sound so good. Not surprisingly, none of my OTL tube amps really did the Denons justice, it would seem. I quite frankly did not think the Denon's could sound this good. The Leben lets them reveal nuance and detail I didn't think was in them.
 
I did some rolling with the CS300X.  I tool out the RCA grey-plate ^BQ5's, and put in JAN-Sylvania black-plates.  I also took out the Sylvania 5751's and put in JAN-Hytron triple-mica 5751's.  Amazingly, the Leben sounds even better.  I knew there was room for some improvement in the tubes I had in there, but these really do take the Leben up another 5-10% in performance.  The lower-gain 5751 is definitely the best choice for headphones, since the Leben has LOTS of juice for cans.  The 12AX7 might be better for speakers, though.
 
As some users have reported, I have a very slight buzz on my most sensitive headphones.  Can't hear it at all with my LCD-2, Ed 8, HE-5LE, D7000, or T1.  Very slight with W1000X.  More noticeable with the DX1000, but the DX1000 has revealed very small noises of lots of amps that I couldn't hear any noise with any other headphones.  And to be clear - all of the above is with NO music playing - can't hear it at ALL with music playing, with any headphones.
 
I can't really express how much more I prefer the Leben to the other headphone amps I have.  I want to listen to ONLY the Leben.  Unfortunately, I can't take it everywhere   But when I am at my bedside rig, it's a real treat every night to end my day with some time on the CS300X.  It's special.
 
While it's hard to get in the US, it's worth seeking out, IMO.  Very highly recommended!

The HiFiMan HE-5LE represent something of a benchmark in terms of price performance, IMO.  They are excellent sounding, with exceptional detail and transparency.  For the money, they provide a level of performance that wasn't possible just a few short years ago.
 
The HE-5LE have an incredibly open, detailed, transparent and clean sound.  The bass is deep and powerful when called for, but not exaggerated or bloated at all.  The mids are clean as a whistle - not overly lush at all, but not at all thin or brittle.  The highs are also very transparent, with perhaps just a little excess energy in a couple of spots that might make them a tiny bit bright on some systems and for some listeners, even though I did not find them so.  Soundstaging is very good, with good width and depth.
 
The HE-5LE are also extremely comfortable.  They're not super-light, but they have great pads and headband comfort, and don't clamp too hard.  They do require a pretty strong partnering amplifier, though - they need a good deal of current to really sing.  But given that, sing they do!
 
I spent quite a bit of time lately with the HE-5LE in balanced mode, via the excellent APS cable, and using the Blossom amp from Moon Audio.  This was a great pairing from the HE-5LE, and used balanced, they were even better sounding - unfailingly smooth, extended, and very detailed.  The balanced HE-5LE with APS cable and the Blossom amp is a pairing I could happily live with for a LONG time.
 
It should also be noted that the HE-5LE are very, very comfortable.  I can wear them for long periods of time, and hardly feel like they are on.  This is no easy trick, since they aren't the lightest headphone ever made - but they have very comfortable earpads, and a good overall ergonomic design. 
 
 
Especially for the asking price, I think the HE-5LE are great sounding headphones that give you a huge measure of what planar magnetic headphones have to offer without costing an arm ans a leg.  I recommend them highly.

I have had my Scoutmaster for about 6 months.  I've been enjoying it mightily. 
 

 
The Scoutmaster's most noticeable sonic trait is that it provides an incredibly quiet, deep-black background.  With my Benz LP-S, the sound is effortless, organic, and startlingly full-range.  Bass is amazingly solid and deep.  Midrange and treble are pure analog - which is to say, astoundingly lifelike.
 
VPI's are a tiny bit tricky to set up, but I have some experience with them, having had an original Aries before.  After I got it all dialed in, it's been a trouble-free performer.
 
At it's price point, only VPI's own Classic competes, IMO.  Beyond that, you have to spend MUCH more to get a competitive sound.

I was approached by Audiotailor to review a new tube headphone amplifier with a unique circuit design. Of course I was immediately intrigued by the idea. I cannot reveal the details of the design, but it does result in their being two headphone outputs, with different sound signatures. This is the principle “feature” of this otherwise well built and attractive, but otherwise unassuming tube headphone amp. The Jade is made in China, and will sell in the USA for $350 shipped – an attractive price.

Pics:






The Jade uses the current reigning king of headphone amp power tubes – the 6AS7G – as its output tube. The input tube is a 12AX7. The amp uses one of each tube, meaning that one channel rides on one section of each of these dual-triode tubes. I am a fan of the 6AS7G – it is a powerful, good sounding tube that offers a lot of inexpensive tube rolling options. And of course the 12AX7 may be the most popular 9-pin dual-triode ever. That does mean there are some expensive variants here, but there are also affordable options.

My Jade, which is an early production unit, did not come with any tubes, so I cannot comment on the stock tubes, but this is just as well – it surely would have come with Chinese tubes, and I wouldn’t even have used them. For the review I used primarily a GEC 6AS7G and a Sylvania 5751 – my experience is the 5751, which is the lower gain version of the 12AX7, sounds better and is quieter in headphone amplifier applications.

I mentioned mine was an early production review unit, and as such, there were two issues. One is that the 6AS7G’s tube socket was mounted too close to the PCB, and as such, the tube would not insert fully. I alerted Audiotailor, and they have assured me this will be fixed in the final production. It was OK for reviewing, but not acceptable for a buyer, so it’s good they will be correcting that. Also, the volume control was noisy when changing levels. No problem during listening, only when the volume was being changed.

Sonically, the Jade was terrific, but it’s a little hard to write the review since one really has to review the different outputs separately. One output is close to solid state – firm, detailed, deep bass, high resolution, very clear and transparent, and certainly not bright or edgy, but not lush or ripe, either. The soundstage was very well defined, but wider than it was deep. It was actually quite similar to the tube-hybrid Head Direct EF1 in sound, which is to say, excellent. Were this it’s only output, I would recommend the Jade, but not to people who were looking for a “tubey” sounding amp. Its sound is more “Yang” than “Yin”.

The other output was still very open and transparent sounding, but this time the sound was a little softer and sweeter on top, a little warmer throughout, and with just a little less deep bass, but with a little fatter mid-bass. Mids were on the lush side. The soundstage again was very good, but deeper than it was wide. In this case, were this the Jade’s only output, I would have happily recommended the Jade, but to people looking for a tube amp that was a little on the tubey side. So this output is the more “Yin” of the two.

What this does is make the Jade a terrific amp for people who own multiple headphones of different sound signatures. I preferred the “Yang” output with my JVC headphones, but I preferred the “Yin” output with my Beyer headphones. The differences are NOT night and day, but they are easily heard, and they do make headphone matching both easy and fun.

The overall quality of the sound from the Jade was very high for the price. The amp was very quiet. I enjoyed a very wide variety of music, and here again, sometimes I would prefer one kind of music on one or the other of the two outputs, although I normally cannot be bothered with such things. I like to set stuff like that and leave it, so once I identified which of the outputs was best on the specific headphones I was using, I would just leave them that way.
 
The Jade is not the very last word in resolution, or detail.  You can't really expect that from a $350 tube amp, and you don't get it.  But it's very musical, and highly enjoyable nonetheless.

Being a tube amp, it’s possible to tune the amp with different tube choices. I briefly used a Tung-Sol 5998, and it was just slightly less warm. So of course I slightly preferred it with the warmer of the Jade’s outputs. I did not try rolling 5751’s much – I only have RCA’s, Sylvanias, and GE’s, and I do not hear a huge difference amongst these – and what I do hear makes me prefer the Sylvanias.

The Jade will be sold web direct, and at $350 shipped to the USA, I think it’s attractively priced. For me it was definitely better sounding than the Darkvoice 336SE. It certainly compares well with the Head Direct EF1, and does offer the option of the two sound signatures. The Jade had no trouble driving any of my headphones well, but the lowest impedance headphone I now own is 64 ohms, and so the EF1 might still be a better choice for very low impedance headphones like Grados or Denons. And it’s not a giant killer – both my Singlepower amps were better, as one would expect them to be for the price and topology.

In any case, assuming Audiotailor seems to have resolved the small early production issues my review sample had, it gets an enthusiastic recommendation from me as a flexible, good sounding tube amp at an affordable price.