I'm about to buy a used 1987xl 50w plexi that has a master volume mod on it. I can't try it out because it's pretty far away from me. What exactly does the master mod allow me to do? Does it just mean i can crank the loudness knobs and play at a lower volume or will I still lose gain when I turn down the master volume? Sorry if this seems like a stupid question but I don't really have any experience with single channel amps.
In normal circumstances a master volume mod would give you a volume control for the pre amp and a master volume control.