Joel, I went for the more compact platform and single chassis of the WA6. It fits on my desk, next to my computer monitor and my Audeze Deckard SS Class A DAC/AMP. So essentially I have two systems on my desk. Solid State Class A and Tubes.
The WA6 is a Single Ended Triode topology which I strongly prefer with tubes in general. The WA6 was ordered with the Sophia Princess 274B rectifier tube and 13EM7 output tubes.
Sonic signature is as follows. I prefer the WA6 with 300 ohm headphones. Tubes like the higher impedance and this tube amp while offering a switch for two impedance scenarios, to my ears at least, has sounded its best with 300 ohms.
I will speak in the context of WA6 and HD600 as a "system", as it is rather pointless trying to describe it by itself. It will sound different enough with different headphones.
The HD600/WA6 combination with the Sophia and 13EM7 tube upgrades sounds lush, musical, engaging, seducing. Very romantic and relaxed presentation that offers enough leeway to listen to ANY genre and virtually ANY recording quality without fatigue. Bass control and articulation is more than fine and actually beats my main system/speakers.
Midrange is liquid gold. Highs are well controlled and non-fatiguing with enough of a sparkle and shine up top to keep things interesting but this is not your analytical/highly resolving setup if that is what you want.
This is your multi-hour listening marathon combo. The more you listen, the less you want to stop listening.
What is the tradeoff? By comparison to the Audeze Deckard which itself is a Class A, very musical and engaging DAC/AMP combo. The Deckard also drives my WA6 through its variable output section. The Deckard solid state presentation offers just a smidgen more bass articulation, transparency, sparkle and perceived resolution. Minor not major differences here. With the HD600, I can listen for hours with either and I do! Longest listening session was just shy of 6 hours recently. It was magic.
So it also very much depends on the mood. Sometimes I want to engage with a slightly more realistic and less technicolor presentation, so I can dive into the cooler and refreshing but never chilly or cold mountain lake of the Audeze Deckard Class A and sometimes I want to stay and bathe in the warm oceans of the WOO coast. Either way, the combo is fantastic for Jazz, Classical, Vocals and even Rock. The smooth, supple, lush and forgiving sonic signature does not offend the ear but tends to sugar coat everything just enough to be very enjoyable and palatable.
I can not compare to any other WOO amps as I have only briefly heard the WA2 not the 22. WA2 was fantastic. Very similar to WA6 but with a smidgen more magic, openness and sparkle.
Joel, I think if you are looking for a very romantic and analog sound, you want to be headed for the SET/OTL topology. I would suggest the WA2.
You want the single ended triode and output tranformerless topology with the HD600 or the ZMF Headphones if you ever decide to get either. The combo is magic and you have the PHC1 guarantee on that.
