B-52 AT-212 problem

[noahc72]

I bought a B-52 AT-212 tube amp from a guy who said it worked great if you found the right plug to plug it into, but would usually blow the GFIs in his house. It worked fine in his garage. I brought it home and plugged in it (power switch off bypass switch on bypass) and it immediately tripped the circuit breaker, not just the GFI.

Any idea what the problem would be?

[52 Bill]

The obvious answer here is that it is drawing too much current for the circuit breaker. These amps should work fine with your basic 20 amp line circuit, so there may be a problem with the tubes, or the power supply.

Does the amp have the correct value fuses installed?

[tboy]

If it trips the breaker even with the power switch off, that narrows down the possibilities considerably. There has to be a short somewhere upstream of the power switch. The first thing to check would be the power cord. It has a removable cord, so remove it and check it for shorts with a multimeter. If you don't have a meter, or don't know how to check it, then I would strongly suggest taking the amp to a qualified technician. I hope it goes without saying that you shouldn't plug the amp in again until the problem is found and corrected.

[noahc72]

When I bought it I was hoping it was just the power cord, but I've tried a few and they all produce the same result. It looks like it was the right fuse, but I'm taking it to a tech tomorrow.