Ground noise and hum: why and how to maybe fix it

[bwaslo]

Since there's no forum for BOTH SS and Tube amps, I'm putting this notice in both forums (hope that is ok). Have problems with hum when stuff gets connected together? Here's what is going on and how you can maybe fix it easily.

Please see:
http://www.diyaudio.com/forums/blogs/bwaslo/1309-ground-loop-noise-why-what-you-might-do-about.html

Thanks! Bill

 

[SY]

If memory serves, this is what Dynaco used to do. They had other grounding issues, but this trick got rid of a lot of hum.

 

[bwaslo]

Yeah, I think I've seen something similar in a Hafler amp, too (just on one channel, though, oddly?). But it's good to see that there's math there behind it, and how to perhaps apply it.