this was an earlier thread from about a year and a half ago:
There was a lot of argument and resulting trial and error there, and the consensus seemed to be 100wpc min but vintage amps don’t always apply to the same rules as I can personally vouch for. I’m not familiar with that amp, but I didn’t look it up before you linked it. You may be ok with that, and I would bet it’d do better for you than the 789.
As for the polar opposite of the A2C, the Audeze XC will not be super comfortable, but I’ve been using mine a lot more since I installed Roon and the Audeze EQ is built in-it makes a big difference. I own the wooden backs, and it doesn’t look like they sell those any more. The weight reduction may be nice with the carbon version, but the wood is very pretty. My favorite closed back, and maybe my favorite headphone even though I own “better” is the ZMF Eikon