MINI-Review: Woo WA22I had the WA22 prototype here for two weeks for the Colorado meet, while jack took the first production model to the NJ meet that same weekend. It had a pair of RCA 12AU7, Sophia Princess 274b rectifier, and a pair of Sylvania 7236. And I compared it to my WA6 and EC ZDT.
I hooked up the WA22 to my PS Audio DLIII via XLR out with anti-cables interconnects, and my WA6 via PS Audio RCA out with anti-cables RCA interconnects. I used HD600, HD800, K1000 and woodied D2000 with 4-pin XLR, with a single ended adapter so I could listen to both amps with the same phones. I also used Grado HF-2 and woodied D7000 single ended with both amps.
Compared to my maxed WA6 (with PDPS and Sophia Princess 274b rectifier and a pair of RCA 6DE7) the WA22 had a bigger and wider soundstage with more depth as well, and better channel separation, with gobs more power - even single ended it was better. Dynamics were great, and it never seemed to run out of power with everything but the K1000.
Moving from the WA22 to the WA6 resulted in the sound becoming more forward and narrower. Interestingly the WA6 sounded great until compared with the WA22, and the tonal balance and detail of the two amps was very similar. It was mostly in the soundstage, separation and power where the WA22 ruled. The WA6 cannot begin to pretend to drive the K1000 though. The WA22 was also very close to my Eddie Current ZDT, except the ZDT was clearly better with K1000 and slightly better with D2000. With Grado HF-2 and LA7000 the WA22 and ZDT became closer in sound quality again.
I was very impressed with the WA22 prototype, and for a while considered selling my WA6 to get one, but in the end the WA6 still makes a good amp for the bedroom since the ZDT gets too hot to keep in there.