I just got a 5150 III half-stack on friday. Happy to report that this amp kicks all kinds of ass!! As many have already said, the EVH cab is crucial to getting that tone. I have two Bogner cabs which sound good with the 5150...but the EVH cab just smokes with this head (and with my other amps as well). The clean can stay totally clean but also can be pushed to break up in a very usable way. The second and third channels both sound very raw and stay very clear even with gain dimed. Mine came with a combo of Sovtek 12ax7WCs (slots 1 & 5), EH (slots 2,3,4,6) and LPS (slots 7,8) pre-amp tubes and Sovtek 6L6 WXT power tubes......