Update: while I loved the Nitro with KT88'S, I found I really couldn't run the gain above 9 o'clock. Just too much saturation and bass--as a result, didn't cut in a band mix. Got some Ruby EL34BSTR from Laura and now it destroys, both alone and in the mix. Winged =C= EL34'S sound great in it as well; I prefer the mids of the Rubys.