I have a Triple X and while I like the base tone it can be somewhat limiting having George Lynch type tone ALL the time. I realize that the circuit will always sound more or less like itself but would lower output preamp tubes make the gain knob more usable? There is a lot of gain in this amp and dialing the gain down for more of a heavy 70's style sound gives less than awe inspiring results. The clean channel is not bad, better than you would believe given what people say. Also thinking about going to EL-34's but given the volume I play at most of the time I don't think it would have much of an impact.