Note: THIS IS A REPUBLISHED REVIEW
This review was originally posted at head-fi.org all the way back in 2012. It was written by Chris before he started Headphoneer, and now it is time to publish it here where it belongs.
The WA2 has not changed much at all, quoting Woo Audio as of April 2023, “…no other changes for WA2 aside from removing the pre-out to improve on the headphone output. WA2 is our longest production amplifier and the current production is best sounding to-date. There are no plans for a 2nd gen model…” It was a nice feature to have the preamp output, but the sonic performance of the headphone output is at least as good as it was.
The WA22, however, has been through some changes, and gotten the “2nd generation” suffix to is name. The WA22 2nd gen. features improvements that lower the noise floor and enhance the output power. Using improved output transformers the already powerful amplifier gives even more power, not that you really need it, the original is powerful enough for most headphones. It also features a fully-balanced preamplifier output, which used to be an optional $400 addition. This this makes the 2nd. Gen. amplifier more expensive. Further it now converts the unbalanced signal to balanced. The first generation did not do that, so if you used the ubalanced input you only got half the power output. That could actually be practical when used with high sensitiv headphones, functioning as a “low gain switch”. I have connected my DAC to the WA22 with both inputs, getting a low and high gain option. For sensitive headphones the WA22 gen 1 can be a bit to loud, making it a difficult to adjust the volume if you don’t have a source we have volume control of course.
The current USD price is 1499 for the WA2 and 2699 for the WA22. Standard tubes included.
Hopefully we get to review the new versions sometime in the future.
The WA22 and WA2 has been used as reference gear on The Headphoneer website since the beginning and has been compared extensively to a range of amplifiers in various reviews. Feel free to check it out. Just search for WA2 or WA22 in the search box here on the site.
Here comes the original review. Happy reading!
INTRODUCTION
I have had the privilege of having these two beautiful amplifiers side by side for a couple of months now. I assume I am not the only one who has been wondering about which one to get, so I’ve tried to contribute with a subjective write-up, including rather subjective track-by-track side-by-side comparison. I have limited the number of headphones to two sets, the HD650 and the LCD-3.
DISCLAIMER
Just to get it clear. I prefer “unbright” sound. I like LCD-2 rev.1, LCD-3, HD650, FostexT50RP. I prefer the Stax 007 to the 009. I’ve owned the HD800 and T1, but both were too bright for me. I think “natural” sound is more appealing than “neutral”. I think “timbre” is more important than “PrAT”. However. I enjoy high levels of detail and transparency, but I am willing to tolerate less of that if the tonal balance feels better – which often means less treble tilted. I do enjoy a powerful presentation, but have a preference for warm, full bodied bass to super tight bass.Thus, I foresee that many head-fiers will disagree with my subjective experiences presented in the following text.
WHAT IS THE DIFFERENCE ?
Price (2012): WA2 is 1090 USD (Stepped attenuator as in WA22 199 extra), WA22 is 1990 USD.
The 2023 USD price is 1499 for the WA2 and 2699 for the WA22 2nd Gen with preamplifier outputs . Standard tubes included.
Output impedance:WA2 is ca 70 ohm +/- 15% (source) depending on tubes.WA22 has a high/low impedance knob similar to the WA6SE – which is measured to 15 or 50 ohm ref. Ken Rockwell review WA6SEWattage: WA22 is significantly more powerful than WA2, but WA2 has more wattage than a lot of headphone amps, especially compared to other OTL tube amps.Functionality: WA22 is fully balanced headphone amp only. For roughly 400 USD you can get a custom balanced pre-amp output. There are RCA and XLR inputs, flip switch on the back.WA2 doubles as a pre-amp in standard version. 4 inputs selected on front panel knob.
WA2 is a SET OTL, (Single Ended Triode, Output Transformer Less) – among the purest of tube constructions. OTL’s (and tubes) generally are better at voltage swings than current, and is usually regarded better for higher impdance headphones. However, WA2 delivers quite a bit of wattage, and I find it to be a good match for the planars/orthos I have tried. These orthos has got a flat impedance response curve, which makes impedance matching less important. There are also people who raves about the WA2 with low impedance phones, especially as well Denon D7000. (see CNET and EnjoyTheMusic reviews)
WA22 is also a Triode, but transformer coupled and fully balanced. It delivers 1,5 Watts into a 30 ohm headphone. It has two options for output impedance, which is quite neat. Often I seem to prefer the low impedance planars with the high output impedance. It makes the sound a bit thicker. A very nice function, you got two amps in one. With HD650 and HD800 it is almost always the High imp setting that works best. I have not tried it any HQ low impedance traditional dynamic headphones.
Woo Audio: htttp://www.wooaudio.com/products/
Woo Tube Compatibility Chart
THE SOUND
They both share what I guess is the Woo “house sound”. Not dark and warm, rather smooth, yet very precise and detailed. Great soundstage. Actually I originally got the to compensate for my former T1’s brightness. I thought that the WA2 (my first tube experience) would add a real dose of warmth to the midrange and roll of the treble enough for me to tolerate the T1. It didn’t work out that way. Some say the WA22 has warmer mids than the WA2, I disagree. But I would say it is more upfront. I feel the high mids are more present in the WA22.
WA22 generally has more bite, sharper edges, is faster, and in a way “thinner” sounding. WA2 is tender, more full-bodied, polite, lush. Not laid back and dull, but a bit less sharply defined. However, it kind of makes things more subtle in a way. If this is really so or just that I am lead to listen more for subtleness with the WA2, I do not know. The peaks are slightly higher and sharper with the WA22, slightly smoother with the WA2. They smoothness of the WA2 is not the warmish type. It is not smooth as honey, but smooth as silk, if you see what I mean.
If I were to use negative vocabulary, the the WA2 would be the flatter and duller one, while the WA22 is the edgier and intrusive one. But I’m not going to put it that way. Every trait has its pros and con. I must emphasize again that they are indeed of the same family. They share more similarities than differences. On some tracks they vary more in presentation than others. They favor different parts of the recording, which draws your attention slightly more to this or that. Both have excellent soundstage and detail, they are great amps.
Focusing on the differences, how would I decribe the comparative advantages of these two beautiful amps in a few words? Well, this is what comes to my mind. But remember, this is comparative – compared to one another, not to other amps:
WA2: Tenderness, timbre and a full-bodied and coherent sound.
WA22: Speed, precision, detail and dynamics..
TRACK BY TRACK
The tracks chosen is from the music I like to listen too these days, but I picked each of them because I find these specific tracks to be good for spotting traits in audio gear. I’m sorry about the lack of well known tunes, but have included direct links to a listen-preview-services. (If the links not work, google is your friend, and I think Amazon has them all – also for pre listen straming).
I have used my own ranking, the SPR – Subjective Preference Ranking. This is only based on what I prefer. Not what sounds most impressive, detailed or whatever, just which amp made me enjoy the music the most. I played all tracks several times with each amp, switching back and forth in varying intervals until I was sure I had made up my mind.
“Subjective Preference-Ranking” explained:
= indicates equal preference, not necessarily that it sounds the same, A >= B indicates A slightly preferred to B , A > B indicates preferred to and A >> B highly preferred to.
Tubes in WA2 on this test: 5998 + Mullard CV2492
Tubes in WA22: RCA6080, Rayethon 6SN7, 5U4G. (I used TS5998, Sylvania 6SN7 and EML5U4G too – but the main differences between the amps are the same).
Source: SB Touch – Lavry DA11 – Nordost Baldur RCA (Y-Split to both amps)
FEEDING THE HD650
Track 1 and 2 – Ipa/Lorena/Ting/Mossabacka. Alternative jazz, fabolous percussion details, bass, intense sax. After about 9 minutes, the track “Ting” has some intense solo drumming, the drum skin licks your ear canals..LISTEN HERE The WA22 has more punch, sounds crispier, faster, better separated. It suits these tracks especially well. WA2 presents a more polite, less edgy and fuller sound, but on these tracks the WA22 really makes the material shine. WA22>>WA2.
Track 3- Radiohead – Kid A -Morning Bell
Rock/Electronica -male vocals
LISTEN HERE The faster WA22 makes the percussive elements stand out more, bass is better defined. However, the vocals feel better on the WA2, which isn’t a slouch in the other aspects either. WA2>=WA22
Track 4 – Ola Bremnes/Hav av tid/Hav av tid
Folky singer songwriter, challenging bass – long deep notes.
LISTEN HERE The WA2 presents the bass surprisingly well, and has an edge on the WA22 on the vocal presentation.
WA2>WA22
Track 5 – Jørn Øien Trio – It should be obvious
LISTEN HERE This percussion based track should favor the WA22. It hits harder and feels more precise. However, it is thinner sounding, and I prefer the WA2 more elegant presentation by a hair..
WA2>=WA22
Track 6 – Jøkleba – Nu Jøk – Muggen Fallskjerm
LISTEN HERE This is also percussion oriented, and I expected the WA22 to win But again, the precision of the big brother makes doesn’t make that much of a different, WA22 feels more restrained in a way, hard to explain, but I prefer the presentation of the WA2
WA2>WA22
Track 7 – Flaten/Kornstad/Christensen – Mitt hjerte altid vanker 1 – For himmerigs land maa man kjempe LISTEN HERE Here, the WA2’s tender mids brings the music out better IMO, but the cymbals have definitely more shimmer with the WA22.
WA2>WA22
Track 8 – Vincente Amigo – Ciudad de las ideas – Compare Manuel (Dedicado Aueco)
Flamenco guitarist, vocals percussion. .
LISTEN HERE Here the WA22 has definitely better separation, clarity, soundstage depth. The percussive elements are more upfront, bass control is better. The WA2 does ok, but all is more relaxed, and feels (I hate to say it) slightly veiled in comparison.
WA22>>WA2
Track 9 – Emerson String Quartet – Three Madrigals for Violin and Viola Op.H 313 – I. Poco allegro
Energetic string quartet piece.
WA22 is crisper, details more u front, but the WA22 has a tenderness in its tone that is hard not to be seduced by.
WA2>WA22
Track 10 – Tord Gustavsen Trio- Changing Places -Turning Point
Slow and gentle jazz trio
LISTEN HERE WA22 tighter bass, harder sound. WA2 is softer, has more charm WA2>WA22
Track 11 – Axioma Ethica Odini Enslaved – Raidho
Hard hitting hard core death heavy screaming double drum black metal
LISTEN HERE WA22 is faster, things are better defined, details stand out more. WA2 does surprisingly well with keeping up with the speed, and its fuller sound has indeed much appeal.
WA22 >= WA2
Track 12 – Jon Balke – Rotor – Khamsin
Almost only piano single notes.
LISTEN HERE WA22 is crispier, WA2 is fuller. Both very nice.
WA22 >= WA2
Track 13 – Vivaldi 4 Seasons – Concerto Nr.4 In F Minor: Winter – I Allegro Non Molto LISTEN HERE WA22 feels more detailed, but somehow the WA2 makes my toe tap more.
WA2 = WA22
Track 14 – Solveig Slettahjell – Domestic Songs – Never Forget The Good Ones
Slow jazz female vocal
LISTEN HERE The tender presentation of the WA2 is just precious. WA22 has a harder edge to it.
WA2 > WA22
Track 15 Olga Konkova – My Voice – As Before
Jazz
LISTEN HERE This song has a very fat piano, which the WA22 handles better. Also the cajón (a spanish percussion instrument – you sit on it (a box) and hits its side between your legs) is presented in a very good way.The vocals are clearer too, without being too sharp.
WA22>WA2
Track 16 John Talabot – Fin – Depak Ine
Ambient/Electronica
LISTEN HERE WA22 makes percussive elements stand out more, slimmer and tighter bass. WA2 presents a more full bodied landscape, a more enveloping sound which is very – well, yeah – enveloping.
WA22=WA2HD650
CONCLUDING: Surprisingly, the way the two amps handled genres didn’t always match my expectations. The WA2 really lifts the so called “veil” off the HD650, if there ever was one (I do not think so – but a wronly amped HD650 can be a bit unsparkling). The HD650 just has a lovely smoothness to it, and if amped right, this smoothness can fit many genres – even black metal. The dynamic range of the WA22 sometimes steals the show, however.
FEEDING THE LCD-3
Track 1 and 2 – Ipa/Lorena/Ting/Mossabacka.
Alternative jazz, fabolous percussion details, bass, intense sax:
LISTEN HERE The WA22 has more punch, sounds crispier, faster, better separated. It suits these tracks especially well. WA2 presents a more polite, less edgy and fuller sound, but on these tracks the The WA2’s politeness suits the LCD-3 better, and opposite of the HD650, I prefer the WA2..
WA2 > WA22
Track 3- Radiohead – Kid A -Morning Bell.
Rock/Electronica -male vocals
LISTEN HERE As with the HD650, the faster WA22 makes the percussive elements stand out more, bass is better defined. However, the vocals just is adorable with the WA2, which again isn’t a slouch in the other aspects either.
WA2 > WA22
Track 4 – Ola Bremnes/Hav av tid/Hav av tid
Folky singer songwriter, challenging bass, male vocals – long deep notes.
LISTEN HERE This track really challenges the bass control abilities, at the same time as there is some male vocals that should be cared for as well. The WA22 has a tighter grip on the LCD-3, and the tonality suits this track superbly. The WA2 does ok, but this is one of the tracks which would make me miss the WA22 the most.
WA22 >> WA2
Track 5 – Jørn Øien Trio 0 It should be obvious
LISTEN HERE The crispier sound of the WA22 works well here, it feels more precise and gives more air
than the WA22, without loosing the charming tonality.
WA22 > WA2
Track 6 – Jøkleba – Nu Jøk – Muggen Fallskjerm
LISTEN HERE Same as track 5. The WA2 has has some advantages, presenter a fuller bass, but still..
WA22>WA2
Track 7 – Flaten/Kornstad/Christensen – Mitt hjerte altid vanker 1 – For himmerigs land maa man kjempe
LISTEN HERE Here, the WA2’s tender mids brings the music out better IMO, but the cymbals have definitely more shimmer with the WA22.
WA2>WA22
Track 8 – Vincente Amigo – Ciudad de las ideas – Compare Manuel (Dedicado Aueco)
Flamenco guitarist, vocals percussion. .
LISTEN HERE As with the HD650, the WA22 has definitely better separation, clarity, soundstage depth. The percussive elements are more upfront, bass control is better, all without getting edgy.
WA22>>WA2
Track 9 – Emerson String Quartet – Three Madrigals for Violin and Viola Op.H 313 – I. Poco allegro
Energetic string quartet piece
music link
The more upfront WA22 may give a higher sense of detail, but those violins on the WA2 are just so silky, so right. Ahh. Both have their right. Tie.
WA2=WA22
Track 10 – Tord Gustavsen – Changing Places -Turning Point
Slow and gentle jazz trio
LISTEN HERE WA22 presents an open and detailed soundscape. The WA2 does too, but just not as good.
WA22 > WA2
Track 11 Enslaved – Axioma Ethica Odini – Raidho
Hard hitting hard core death heavy screaming double drum black metal
LISTEN HERE As with the HD650, the WA22 is faster, things are better defined, details stand out more. WA2 again presents a fuller soundscape, its fast and delicate – presented with that silky airiness the WA2 does so well. (can’t believe I just described Enslaved as “silky”..)
WA22 >= WA2
Track 12 – Jon Balke – Rotor – Khamsin
Almost only piano single notes.
LISTEN HERE WA22 is crispier, clearer, WA2 is fuller. Both nice, but the cripiness suits this track.
WA22 > WA2
Track 13 – Vivaldi 4 Seasons – Concerto Nr.4 In F Minor: Winter – I Allegro Non Molto
LISTEN HERE WA22 presents a crispier and better defined soundstage, but the silkiness of WA2 just makes you wanna lean back and close your eyes. Tie.
WA2 = WA22
Track 14 – Solveig Slettahjell – Domestic Songs – Never Forget The Good Ones
Slow jazz female vocal
LISTEN HERE The silkiness of the WA2 is hard to beat, but the WA22 has its right.
WA2 > WA22
Track 15 Olga Konkova – My Voice – As Before
Jazz. Fat piano Female vocals. Cajón percussion
LISTEN HERE Againg, the silkiness of the WA2 wins. WA22 does a great job with the percussion and stuff, but sounds thinner.
WA2 > WA22
Track 16 John Talabot – Fin – Depak Ine
Ambient/Electronica
LISTEN HERE Similarly to the HD650 experience, the WA22 is sharper and faster, but the WA2 experience is so…enveloping.
WA2 > WA2LCD-3
CONCLUDING: The WA2 brings out the lovely smoothness, the WA22 brings out the bi dynamics. Both work good, but as with the HD650, the only times I used the >> (clearly preferred) indicators, was in favor of the WA22. The advantages of the increased dynamic range of the WA22 is sometimes very dominant. But the WA2 can be soooo sweet.
CONCLUSIONS
I was quite surprised sometimes during these sessions. The WA2 silkiness is just so appealing, and I found myself preferring it to the powerful presentation of WA22 more often than I’d thought. But the WA22 isn’t hard and harsh, it’s just that the WA2 is so smooth. However, there are certain tracks where the WA22’s extreme control just so much better. I assume, though, that others might have different tastes and prefer the clarity of the WA22 more often than I did. Also – audio preferences are not constant. The WA2 can become too smooth sometimes. After I finished the days of “reviewing” (which is a pretty exhausting way to enjoy music) I have no problem enjoying the tracks I preferred on the WA2 with he WA22. The powerful grip the WA22 has on headphones is hard not to miss once you have gotten used to it. But so is the lushness of the WA2 mids, the softer but more enveloping way it paints. None of the Woos are overly warm. They do not roll off the highs. They both do bass. They have overwhealming build quality. They are as good as dead silent thrugh the phones. They both handle the HD650 and the LCD3 very well, but wit different flavor. Both are high class amplifiers and compared to lesser amplifiers, they are outstanding on all parameters, even though they excel more on different traits. Both are recommended.
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I also wrote some comments on the Hifiman HE-500 and the WA2 and WA22 which I posted here:
http://www.head-fi.org/t/402215/the-woo-audio-2/645#post_8629243
For a second opinion, please check out MacedonianHero’s excellent WA2 vs WA22 review:
http://www.head-fi.org/t/562618/woo-audio-wa2-and-wa22-comparisons-finally-finished-whew
The WA6SE vs WA2 review by baka1969 might also be of interest
http://www.head-fi.org/t/555749/sibling-rivalry-the-woo-wa2-vs-the-woo-wa6se-review-posted-update-6-3-2011
This finishes the original review
