Ground Loop Hum


I think that although this subject is covered within the forums that it's worth it to give a solution again as it is a very common and annoying problem. I experienced a hum coming from my speakers after upgrading to a more powerful amp. I knew from the buzz that it was a 60Hz signal from the alternating current in a ground loop. I tried all manner of grounding manuvers and decided to live with it, but then came across an easy solution, less than $10. Here's what you do. First, go to home depot and buy a bunch of 3 to 2 prong (i.e., ungrounded) adapter plugs. Then use one of these on EVERY piece of equipment that you have plugged in (turntable, tuner, speed control, preamp, phono amp, etc), except for the amp, which you leave as a grounded 3 prong plug. Since all the equipment is ultimately interconnected via the amp, none of it remains potentially dangerously ungrounded. And, since there is only one grounding source, the potential for a loop is greatly diminished. Worked like a charm for me.
carja
The only thing that is grounded is your amp. You removed the ground off all the other stuff. The grounds are not interconnected via the amp.
This is not a recommended solution even though it might be effective. The ground connections are there for a reason! If you defeat this you introduce the possibility of shock and fire hazard.

A better solution is to find the culprit and have the AC wiring in it corrected to eliminate the ground loop! Although this is a common problem in older gear there really is no excuse for it in modern equipment. A plan B is to use an isolation transformer to deal with the ground issue.

Or you could hope that your house does not get damaged by fire and that you live to tell about it...