[Fido2]

OK, I have my Woo HP amp plugged into the same outlet as my speaker amp. Just recently I started hearing like a ground fault hum through my speakers. When I unplugged my Woo HP amp the hum immediately stopped. The Woo amp was not turned on at the time either. Any idea what could cause this?

Also I must say that I heard the hum while watching TV through the stereo. I have not noticed it through regular stereo/music listening with the TV off.
I have noticed no hum from the Woo itself while listening to headphones either, just through the TV/stereo listening.

TIA

 

[Skylab]

One of the most notorious causes of ground loops is cable TV. If you have your TV hooked up to your stereo, this could be an issue for you.

You can potentially solve this problem with a balun assembly on the cable hook-up, but first, just try disconnecting the cable feed from the TV and see if you still have the hum.

 

[Fido2]

Thanks Skylab. But why would the hum stop when I unplugged my headphone amp? The hp amp was off at the time also. weird...

 

[Uncle Erik]

You can pick up an isolation transformer on eBay pretty reasonably, sometimes for $20 or less. One of them will fix the ground loop.

 

[john57]

Quote:

Originally Posted by Fido2 /img/forum/go_quote.gif Thanks Skylab. But why would the hum stop when I unplugged my headphone amp? The hp amp was off at the time also. weird...

That because you pull out the connection that was going to the amp power plug ground. Classic ground loop I had the same issue in the past and I used the pervious poster fix and works just fine.