Hand wired, Transistor based Overdrive. Post knob controls the volume, Pre controls the gain, Bright control is your tone stackâ€¦ adding more bite as you turn it up. The Premium sounds like a very natural amp gain. Itâ€™s open and raw, gets great feedback when cranked, and stacks very well. These are nowhere in the realm of TS overdrives, so if thatâ€™s what you want, look elsewhere. Warm and bluesy, saturated full stack, bright gain boost for solosâ€¦ itâ€™s in there. No buffers, True Bypass. 9V battery or neg. ground DC jack.