This amp sounds great in overdrive mode, which is half the reason I wanted it so bad. However, I was expecting significantly more clean headroom on this amp. With the master volume full up, anything past barely cracked on the preamp knob makes the amp start to break up. I guess the amp could be biased hot in the power section, but I was wondering if anyone else had any suggestions on how to make the amp cleaner. Any tube rolling or other suggestions? I was hoping for a very loud clean tone with the master up, and enough gain for old school rock with the master down and the preamp knob up past noon. HELP?!