#1
boogie 50 cal.

in the lead channel, i've got the gain knob, the master vol, and the lead master vol. all working at once. question is, what's the difference between the master and the lead master volumes?
#2
Gain is probably the amount of Pre amp gain.

Master Volume is probably the overall volume of the amp. This will lower all the channels.

Lead Master is probably just the Lead channel volume.