Hey all. I own a Randall Rg100 G3 which is an extremely loud amp. It has two channels; clean and overdrive and they each have a separate level control, as well the master volume.

My question is (and I guess this would be for amps in general, not just mine) is: how is the tone/dynamics affected when the channel level is cranked and the master not so much, or when rolling off the channel level and having more master volume? Are the levels just there to balance channel volume or can you dial in a more precise tone by boosting the level of one knob?
Basically, the channel volume controls preamp volume and the master controls power amp volume. You'll notice that power amp volume is a lot cleaner and less compressed. This is something you can figure out for yourself fairly easily by turning one way down and the other way up, then switching them, then finding a middle setting.