Andy,
I agree with Celtic66. I just bought the Fully modded Cayin TA-30 from Paul. I absolutely love it. I'm sure your
Epos M12's will love it, as well. I'd recommend
replacing the stock Cayin EL-34's with Electro-Harmonix, or down the line, Mullard's. As, finances permit! Also, if you need more bass slam, the Cayin accepts KT-88's. Paul offers a 14 day return policy. Even if you decide that the Cayin is not your"cup of tea", you can easily sell it because it's in such high demand. Rightfully so!
Good luck in your search.
mmaudio