I hear a lot about the Tourmaster, but every time I have played it I havent been very impressed. Maybe I'm an idiot but after 4 different sittings of about a half hour each I've concluded that it is a mediocre amp.
you know i felt the same way the first time i played through the head. i was at guitar center one day playing through a jsx and some very odd individual wheeled in the tourmaster head and cab. he was tweaking away at the controls and proceeded to crank it (playing through some hollowbody) and it sounded awful. of course he thought it sounded amazing, lol. after chatting with the salesguy for awhile, he turns to me and asks me to play through the amp (i'm guessing because he played like a novice). i was really in there to try out the jsx, so i didn't put a lot of effort into tweaking and completely readjusting his whacked out settings (gain, presence and treble at 10, lol), but i wasn't impressed. i had read a lot of good stuff though, so i vowed to come back and try it again one day.
when i tried the combo the other day, i did pretty much like microdmitry suggested and turned all controls (except for volume of course) to 12 oclock. the tone was very warm, punchy, thick and harmonically active, even at a low volume. i only got better as i turned it up. i was playing through a standard explorer (the real reason for my visit) which has fairly hot ceramic pickups and it was heavenly. one other thing, when i went back in again to just look at the amp, i noticed all the channels were set for 10w, which makes since it sounded so good at low volumes. you may want to play with that (on the back of the amp) because i'm sure it makes a world of difference headroom-wise and tonally.