He plays a JSX through two Lab Series 4x12s, and usually has it set with the presence and resonance both all the way up, treble around 8, mids around 2 or 3, and bass at 9 or 10, on the Ultra channel, which has an active EQ...meaning that those settings are REALLY scooped, boomy, and harsh
so last week after practice, i suggested perhaps we could try starting off the next practice (tonight) with everything at 5, and tweaking from there until he liked what he heard. when we got there tonight, i made sure everything except volume was set to 5, and then had him play with the band for a couple minutes while i turned it up to a usable level, and asked him what he wanted me to do with the EQ. amazingly, he didn't even ask for any changes from anything, with it all still set at 5...didn't ask where his amp's balls went, and said it sounded so much clearer. it stayed set that way all night
now to get some new tubes in that amp... (it's had the same ones in it for about 3 years )
Even I know to change tubes more frequently.