I recently aquired an ampeg b3 115 combo (discontinued) from a pawn shop for $320. Did I do good? Ok, question: Is it safe to turn volume up past half (5)? I have done it a few times but every once and a while I will get this ungodly beep or a poppingcrackle noise. I play pretty aggressively and I like to dig in. Its 150 watts BTW. Not sure how to explain it. Kinda scared to test it out... Second: What exactly do the knobs do? Gain: ? Drive: ? Bass: duh. Ultra Mid: assuming its the same as mid. Treble: yeah. Its just Gain & Drive that need explaining. THANKS!!!