I bought this amp from a guy who had no idea what was wrong with it. I new it was a good amp and the price I paid for it was a steal. I took it in to get fixed and it came out sounding new, however before I took it home, I tested it at the place where I got it fixed and it seemed to have trouble with the sound. We found that it was the preamp tube and that guy told me it wasn't set/socketed correctly. When I come home to play, no sound. I tried taking the tube out and putting it back in and nothing. I even replaced the tube but still nothing. Do any of you know what may be going on before I take it in?