I recently bought an Ampeg Svt400-T and its really quiet. I've tried all combinations of speakers, cabs, wiring, mono-stereo, 810's, 410's, 210's, 115's. you name it i've tried it. The volume just isn't there. My buddy has the same head, and he has beaten that thing up, and its way louder. I've taken it to 2 different ampeg service techs, and they said it was a limit defeat switch is stuck on. I was wondering if anyone had a different idea or has come across this same problem. The head is all solid state. Any help or suggestions would be greatly appreciated.