Big Sound 2015 Wrap: My Take on the Headphone Amps

I'm breaking up my last two posts on Big Sound into amps here, then headphones next—keeping the pageview gods happy, don't ya' know. Also, I'm not going to individually mention the DACs because they all sounded very good, very similar, and were not the primary focus of the event. I just don't have much to say about them other than were I in the market for one of the three, I'd probably choose the Yggdrasil due to it's relatively low cost and good feature set...and it sounded punchy and dynamic to me, which I like.

BigSound2015_Wrap3_Photo_TyllsScoreNeed to get this out of the way before I start with the amps though: my blind test scores. Maybe a little above average for the group. I could have done better if I wanted to spend a half a day and hard concentration doing it...but A) that's a lot of work and didn't want to do it, and 2) the participants did it within and hour or so—they wanted to get on with the headphone listening, of course—and without a lot of practice. I reckon my scores show that it's hard even when you've done it a lot...and probably that 59 year old ears ain't as good as they used to be. Romaz has some good ears!

In my upcoming headphone article, I'll tally up the participant's scores on headphones. Most didn't score amps in meaningful ways, so there won't be any participant tally on amps. You'll just have to go through the articles and glean the info through the narrative.

Okay, on with the show:

My take on Big Sound Amps
I have to preface this by saying that there are a lot of really good, high-end amps out there and just because it didn't show up at Big Sound doesn't mean they're not as good as those that did. I'd love to have had a TTVJ Pinnacle to complement the Woo—not that the Teton didn't hold its own quite well—but Todd didn't have one available. And I'd have loved to have seen how well the new Cavalli Carbon would have compared in the group—it's far less expensive than the Big Sound amps, but it does sound really good. (Caution: trade show impressions!) Anyhow, you should consider Big Sound gear as a representative sampling of good high-end gear, and not a comprehensive survey.

(If interested in the headphone amp measurements, go to the "Getting Some Numbers" article.)

In order of least likely, to most likely, to please me for the long run, here are my thoughts:

Bakoon HPA-21 ($2995)
BigSound2015_Wrap3_Photo_BakoonThis is a current drive amplifier. The topic of what a current drive amplifier is, and the nature of their performance is extremely complex. I will eventually do an article about soon as I figure out/learn the details and do a few tests and measurements myself. Suffice it to say I think the idea is very interesting and likely to hold promise, but it's also very difficult to implement without significant trouble interacting with the varying impedance of some headphones.

One thing that current drive promises to achieve is very well controlled transient performance. I thought the Bakoon did an excellent job of producing a quick, clean treble. In my experience, one sure sign of excellent treble articulation is how smooth it sounds. I've sat in the circle with the Mure String Quartet once and the strings had zero stridency to them; they were absolutely smooth. For me, the Bakoon had this character: articulate, but very smooth transient detail.

Unfortunately, it reacted strongly with the HD 800's huge primary driver resonance hump (nominal 300 Ohm, 600 Ohms at resonance) making the HD 800 exhibit a nice warm bass at first listen, and then the realisation would arrise that it was overly wooly sounding. With the flat reactance of planar magnetic cans, the Bakoon was more well behaved tonally, but the poor damping factor and the fact that PM headphones tend not to image as well as the HD 800 tended to negate the speed advantages of current drive, it seemed to me.

I'm really not sure what to think yet and recommend caution when considering a current drive amplifier, but I will be hanging on to the Bakoon and will be acquiring a few more current drive amps to play around with this technology and report back. (It'll take a while.)

Burson Audio Conductor Virtuoso ($1495 w/PCM1793; $1995 w/ESS1908)
BigSound2015_Wrap3_Photo_BursonThe Burson was one of the least expensive amplifiers of the bunch—probably the least when you consider it has an integrated DAC.

The unit at Big Sound had a wobbly knob; it's most likely something loosened up during shipment. This put the amp at a bit of a perceptual disadvantage. Also, due to limitations on available dedicated DACs, the Burson was often running off its internal DAC, which was understandably inferior to the multi-thousand dollar DACs elsewhere driving amps in the system.

My take is that its actually a decent amp at its price with those features, and worth an audition when shopping, but the Conductor Virtuoso didn't quite play in the same league sonically as the more expensive amps. For me it was less refined sounding and less engaging.

Schiit Ragnarok ($1699)
BigSound2015_Wrap3_Photo_SchiitThis is where the picking gets hard. The Ragnarok and all the remaining amps were really good; all having strengths and weaknesses comparatively that make it somewhat silly to rank them in a particular order. A lot of this is guided by personal values.

The Ragnarok is a beast of an amp, and like all the Schiit gear, available at a really attractive price. It's a perfect complement for hard-to-drive headphones in balanced mode. And it's also a 60 Watts/channel speaker amplifier, if you happen to want an integrated amp as well. One unusual thing about this amp is that it uses a circlotron circuit topology that inherently delivers a balanced output. The unbalanced outputs of the Rag, in Jason Stoddard's own words, are utility outputs—they work, but the amps isn't designed to optimize them for great sound.

I thought the sound in balanced mode was very good, especially with the planar magnetic cans. Well balanced bottom to top and had heaps of power to spare in all areas. To my ears it fell a bit behind some of the other amps in terms of finesse and air, however; I did feel it as a bit lifeless relative to the best amps of the bunch. I'd consider this amp a pretty damned good solution if you've got balanced planar magnetic headphones and need to drive some small-ish speakers, but I don't feel it's the best solution for HD 800 owners looking for world class resolution.

Violectric V281 ($2299)
BigSound2015_Wrap3_Photo_ViolectricThe sound of the V281 was solid and right down the middle. Plenty of weight in the bass, and good balance and evenness broadly; the feature set is very good (it even has a balance control); and the build quality seemed quite good. The only problem I had with it was a modest lack of engagement relative to the other amps; it didn't sound as smooth and liquid to my ears.

None the less, it showed itself as competent, and even a favorite for some of the Big Sound participants. I certainly would feel pretty good about having one of my own were I your average headphone enthusiast. The Violectric is a very versatile and competent headphone amp.

Eddie Current Black Widow ($1248)
BigSound2015_Wrap3_Photo_EddieCurrentThe Black Widow ranks as high as it does based strongly on it's relatively low cost and surprisingly musical (read "colored in a good way") sound. The words that come to my mind are "meaty musicality."

Based on the sound, a number of the participants thought it was tube amp. Romaz, who did so well on the blind tests, loved it and said of it, "From a value standpoint, however, I would probably go with the Black Widow once again. At $1,200, this headphone amp easily presents the best bang for the buck of the group." I agree; if you like a warm, powerful sound, this amp is a sweet choice. I'd be careful of pairing it with warm headphones as the combination might get a bit too wooly, but with leaner headphones like the Ether, or more so the HD 800, this amp might make for a really sweet set-up. When I get the time, I'll ask Craig Uthus for a review loaner. This amp makes me smile.

Woo Audio WA-234 ($15,900)
BigSound2015_Wrap3_Photo_WooHell, it's a toss-up whether to put the WA-234 first or the Teton. In the end I find myself having to give the Teton the nod due to the very high price of the Woo...and terrifically good audio performance of the Teton.

But make no mistake, the WA-234 is a spectacularly cool amplifier not only possessing great sound but giving the proud owner the ability to play around with many tube variations using the unique tube switching keys that effectively re-wire the amp for various tubes. Let's just say, if you've got a boat over 40 feet long and are a vacuum tube aficionado, this just might be the amp for you. I have to admit that when I had a half hour to just kick back and listen late in the evening, this is the amp I'd fire up.

Apex High Fi Audio (TTVJ) Teton ($5000)
BigSound2015_Wrap3_Photo_TTVJHere's how good the Teton is: In the blind test rounds, people had a very hard time telling the Teton from the Moon 430HA. Most participants, it seemed, could clearly tell the difference between the Woo tube amp and the solid-state amps...they even mistakenly, on occasion, identified the Black Widow as a tube amp. The Teton is so well behaved that it's a bit of a chameleon: it has the smoothness and natural speed of a tube amp, without being overly romantic in its character.

My only caution is the Teton, with its relatively high output impedance (OTL tube amp, around 120 Ohms) might not be a good match for low impedance (under 100 Ohms) dynamic driver headphones. On the other hand, low impedance planar magnetic cans seem to perform quite well with the Teton as long as you're not looking for an amp with extraordinary slam and dynamics. If I were in the market for a tube amp, I'd go for the Bottlehead Crack if I was on a budget, but if I had some serious dough to part with, the Teton would be at the top of my list. Unreservedly recommended.

HeadAmp GS-X Mk2 ($2800)
BigSound2015_Wrap3_Photo_HeadAmpWere I personally in the market for a solid-state amp, this would likely be it. Though tilted ever so slightly to the lean sounding side—which is not my preference—the treble performance of the GS-X Mk2 is simply superb. It was Bob Katz's pick of the litter (disregarding his DIY M3), and pretty much all the participants heard it as a terrific performer—though some were troubled by it's slightly lean character.

Add to the superb sonic performance an absolutely flawless and not extravagantly expensive fit-and-finish, the HeadAmp GS-X Mk2 is firmly in its place as a world-class solid-state headphone amp. Lust-worthy is the adjective that rushes to my mind. If I can get my hands on one for an extended period of time, I'd review the heck out of it.

Simaudio MOON Neo 430 HA ($4300 w/DAC)
BigSound2015_Wrap3_Photo_SimaudioThis amp will be going back to Simaudio when they pry it from my cold, dead fingers. Okay...until I find something even better for my needs—which is likely to be a while, it seems to me. The Simaudio Moon Neo 430HA is a reviewer's dream amp; I'm replacing my AURALIiC Taurus Mk2 with it. The AURALiC is lovely, but the somewhat better sonic performance and killer feature set make the Moon a terrifically versatile amp, able to excel in broad manner without giving up much at all in any one aspect.

Yes, the GS-X Mk2 bests the 430HA in terms of treble resolution by a modest margin to my ears, but the flexibility of a broader range of inputs and outputs; a super-dooper volume control that offers the finest control of volume setting I've experienced; and a very competent built-in DAC make it irresistible for my needs as a professional reviewer. At its price, I think many headphone enthusiasts simply in it for the pleasure may want to consider the Teton or GS-X (with an outboard DAC), but if you're the kind of enthusiast that has a lot of headphones and wants an amp that will do it all, and do it well, the 430HA may be just the ticket. I love it, and will be reviewing it soon!

Next post...last one for Big Sound 2015...the headphones. Stay tuned!

Equipment List

Front End
NAS - Synology DS414 ($479)
Renderer - Aurender W20 (~$17,600);
Digital Distribution Amps - Four ATI DMM100 Digital Matchmakers
and one DDA212-XLR digital audio distribution amp ($1450).

Power Conditioning
PS Audio, two P10 power regeneration station ($4999) and four DecTet conditioned plug strips ($499).

AURALiC Vega DAC ($3499)
Simaudio MOON Neo 430 HA ($4300 w/DAC).
HeadAmp GS-X Mk2 ($2800)
Schiit Ragnarok ($1699) and Yggdrasil ($2299)
Burson Audio Conductor Virtuoso ($1495 w/PCM1793; $1995 w/ESS1908)
Woo Audio WA-234 ($15,900)
Antelope Audio Zodiac Platinum DSD DAC, Voltikus Power Supply, and 10M Rubidium Atomic Clock. ($13,045)
Apex High Fi Audio (TTVJ) Teton ($5000)
Eddie Current Black Widow ($1248)
Violectric V281 ($2299)
Bakoon HPA-21 ($2995) current output headphone amplifier.
KGSSSRE (Kevin Gilmore Solid State Special Reviewer's Edition E-Stat Amp ($Unobtanium)

Sennheiser HD 800 ($1599)
Audeze LCD-3 ($1945) and LCD-X ($1699)
JPS Labs Abyss AB-1266 ($5495)
Stax SR-009 ($4450) and SR-007 ($2350)
HIFIMAN HE-1000 ($3000)
Mr. Speakers Ether ($1499)
Enigmacoustics Dharma (~$1200)
Audio Zenith PMx2 ($1398)

Digital cables by AudioQuest.
Cable complements for wiring entire systems will be from: Nordost; JPS Labs; WyWires; Cable Pro; AudioQuest, and Cardas.

Headphone stands by Klutz Designs

longbowbbs's picture

Loved the whole Big Sound process Tyll! We need to start a Moon 430 fan club. I bought one too and it is not going anywhere!

ab_ba's picture

Tyll, which differences betwen amps would you call small, and which were big?

Tyll Hertsens's picture
Well, the Bakoon sounded very different with the headphones that had a high impedance swing, it was the only really different one.

The Woo was tube-like in the traditional sense; I was using the 300B, so it was pretty nicely lush. The Eddie Current stood out in the crowd with its unabashed musicality.

The rest were objectively quite close, but certainly, in long listening, they all would have their distinctive character.

chik0240's picture

Tyll, If I remember correctly I've seen the Taurus mk II in the Bigsound equipment list in the very first, while I know you rank it below the Moon Audio HA430, can you comment a bit about it's comparison to say the V281 and the burson etc? since for a "budget" audiophile this might be more interesting about their relative strength and maybe how much a professional reviewer think we will be missing with choosing either of these instead of the much more expensive options.

Tyll Hertsens's picture
I'd say it's absolutely on par with the's a very good amp. But I didn't have room for it in the comparisons, and didn't do any specific comparative listening with it, so I really don't have any comments more than that.
Mr AC's picture


Any thoughts on how the DAC in the 430HA compares to the Yggy?

Thanks for this test! Very enlightening!

Tyll Hertsens's picture
I thought the Yggy was better by a meaningful margin. The DAC in the 430HA is quite good though.
gevorg's picture

Very interesting thoughts on the amps. Price and features aside, which solid state amp gives you the most pleasant sound with HD800s? The Moon?

Tyll Hertsens's picture
...mmmmm, I'd probably prefer the Moon with my modded HD800s, but the Black Widow might pair very nicely with an unmodded pair.
Johan B's picture


Do you think that T-style amps could do an equal job considering these amps often have DC power supply from batteries? It seems a bit like overkill to put so much money on the table for an Amp that requires limited power output. Another thing I noticed from German magazines is that they measure phase shift versus power and so the power output stability? Is that possible for relative small outputs like with Headphone amps?

Tyll Hertsens's picture
I'm not sure I understand what you mean by "T-style" amps. Do you mean class-D amplifiers?
romaz's picture

I so enjoyed reading your impressions. You kept neutral for so long as you waited for everyone else to weigh in but it was nice to finally hear your take on things. I look forward to hearing your impressions of the headphones.

MCAL's picture

Tyll, thanks for spending energy and effort on this "Process". I have learned a lot. Especially refreshing is your ability to inform your readers using understandable language. For me, the next post on the 'phones themselves will be the most interesting. I have been listening to music since the late 1960's and have considered the key part of the audio chain to always be the final transducer.

zonto's picture

Hi Tyll,

Thanks again for posting your impressions. Based on the headphone amplifiers you've reviewed for Big Sound 2015 or otherwise, do you think the Moon 430HA has any competition in its functionality as a preamplifier for a stereo speaker system?

Based on what I've read it seems that there's not a unit that would integrate as well into a combination headphone / video 2.0 system as the 430HA. Many other units that manufacturers advertise as being combination headphone amplifiers and stereo preamplifiers don't even come with a remote control (something I consider essential for a speaker system).

Thanks again, and look forward to your headphone impressions!

Tyll Hertsens's picture
I think it would make a dandy pre-amp, and it's well suited for it.
Rotijon's picture

Hey Tyll,

I was wondering which do you prefer for the HD800, a ECP L2 or EC Blackwidow?

abelian's picture

Great work on Big Sound 2015, Tyll! Two questions:

1. The Woo is 15k. Throw in a TOTL DAC, say the Mirus (5k), TOTL phones (say the HE-1ks) (3k), and TOTL source (10k). That's 33k. The Orpheus can be had for 60k. Have you ever had a chance to hear the Orpheus, and how does it stack up to the stuff you listened to.

2. Is the Eddie Current Balancing Act inferior to the Teton? If so, is there a balanced amp that competes in the same range as the Teton?