What I like about Woo....
I own both a Woo WA22 and an Eddie Current Super 7. I have owned the Woo 22 for quite a while now and until recently was not all that thrilled by it. Seemed to be immune to 6SN7 tube rolling. I even bought some Mullard CV181s. The sound was always about the same. Very detailed, but honestly a bit dry...reminded me of the Luxman P1-u I used to own. What really makes the WA22 sing is the 6F8G tube (with adaptors). I am using RCAs and Tung Sols and, for whatever reason, those tubes just improve the liquidity of the amp in a big way. Mind you, the Woo is not a lush sounding tube amp, but it now sounds a lot more inviting and enveloping than with any 6SN7s I tried with it.
Now, the Super 7 is a different animal. From the get-go, it has a more enveloping sound than the Woo. The music just flows so invitingly. Although Eddie Current got a reputation for "hard" sounding amps when the Zana Deux was king of the mat, that is not my impression. The Super 7 is about as close as I have heard to my Singlepower Extreme, a stellar sounding amp, regardless of all the build quality issues. The mid-range is rich, warm, and detailed. And it also has better bass than the Woo, which presents fast bass, but not the same level of detail as the Super 7. Overall, the Super 7 sounds more like a SET amp...it presents a very deep soundstage, with lots of detail. The Woo sounds more like my Pass Labs amp. The only weakness of the Super 7 is that with very low impedance headphones (IEMs like the JH16s), I hear a bit of tube hiss, not noticeable when music is playing. But the Woo is completely quiet with every headphone I have used with it.
I would say the Super 7 outperforms the WA22 in terms of sound quality. Craig Uthus deserves his stellar reputation. Turning out the first batch of Super 7s for $1350 was an incredible achievement.
But one reason I probably will never sell the WA22 is its fantastic build quality. I don't expect to ever have to return it for repairs. The Super 7 also has good build quality, but has a slightly more DIY feel to it than the Woo. I have learned the hard way, from my trail of tears owning a SInglepower Extreme, that build quality and reliablity should be cherished. The Woo just has the feel of an amp that will last forever. For that, Woo Audio deserves a tremendous amount of credit.
And now that the Super 7 retails for the same price as the Woo 22, it is a closer call between the two amps. In all honesty, a complete toss up that depends on what type of presentation you prefer. If you like rich-sounding tube amps, or use medium or high impedance headphones (anything above 30 ohms), the Super 7 will sound better.
If you like a cleaner, faster presentation, something closer to solid state with only hints of tube warmth, if you are driving very low impedance headphones (Grados or custom iEM's), and really want an amp that is built like a Sherman tank, then the Woo 22 will do the trick.