I'm in the process of picking up a vintage early 70's Ampeg V4B through a reseller that knows very little about the amp other than the fact that it has recently been re-tubed. The power section tubes are 7027s that look new so I'm pretty psyched. The amp sounds good, but I didn't get to play it long enough to figured out all of the beta. The channel 1 input and channel 2 input are apparently designed to get different sounds. Does anyone know what the different inputs are for? I've looked up the pre-amp schematics on the web, but I don't really understand the schematic enough to figure out the intended purpose of the two inputs. Any info on these amps would be helpful. Also, any suggested power amps to run as a slave for more power?