That amp looks pretty sweet in the dark shots.

This is some serious gear with a very decent design I'm a bit surprised about the hiss issues and that there's no option to optimize this. It's quite annoying when it happens to your favorite IEMs/cans...

Well to be fair, a bit of hiss on sensitive headphones/iems from a massive tube amp pushing 5 watts per channel is not at all unexpected. In fact I would be pretty shocked if it didn't happen.

Thanks a lot for the review. BTW, where have you had your K812 modded? Best, Érico.

Thanks for a definitive review of this amp. Everything a potential owner of the amp could want to know is right here. Re a 24-stepped pot: I've had trouble w/pots like this in the past. Depending on the exact amp/HP/DAC combination, it's too easy to get trapped in the bottom 1-2 steps w/far too much volume above. If I was in the market for this amp, I would be asking Cayin to upgrade the 24-stepped pot to a DACT unit or 47-step Goldpoint pot. Great review!

My K812 was modded by Peterek who seems to have either retired or taken a hiatus from the biz.

Wonder how this would drive KSC-75s.

I heard this amp in a number of occasions with Utopia, HD800, LCD4, Susvara, HE1000. It has a typical 300B sound. Directly compared to a great SS amp like the AGD HE9, this amp has a sound which emerges from the bottom. Not that the tonality less neutral, but the soundscape seems more rooted to the ground than being floating in the air. And by comparison, I actually like this amp better than my Eddie Current BA, and the best SS amp I heard, the HE9. Definitely one of the very best amps around.

Thanks for a great review!