I've been out of the country working for quite a while and, therefore, was unable to work on any of the projects I'd started before I left. However, I've been back for about a month now, and I immediately resurrected my 3300 project. I tried to bring it up today, of course, with a dim bulb tester. Everything turns on fine, but there is a signal only to one channel, and even that signal is so weak I have to turn the volume up all the way to get just a whisper of music. The other channel appears dead, even after swapping channels with the cord, swapping cords, and swapping channels out of the amp. Additionally, when the unit turns on with speakers hooked to it and connected to the amp, on power-up, both woofer cones suck back toward the magnet, and then slowly return to normal position. Now, this pre never worked properly. Someone gave it to me because it wasn't working. When I powered it up, before I ever took it apart, it did the same thing to the speakers, alternately sucking and releasing the driver cones toward the magnets. Also, there has always been a problem with the power switch. I cleaned and nursed it, but it only stays on. The switch clicks when the button is depressed, but it doesn't disengage and it doesn't hold the button back in the on position. The button always jumps back to the off position, even though the power remains on. The leds are all on/lighted up, but there is something terribly wrong. But nearly every part is brand new, other than the switches and the transformer. Any thoughts? Obviously, I need to swap out the power switch, if I can find a replacement, but I'm doubtful that's the source of the problem.