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Ground Loop Issues

I know this topic has been kicked around many times on this website, but I have not found the answer I am looking for. The current setup has a pair of Bryston 7B-ST monos plugged directly into a 20 amp dedicated circuit. The rest of the system is plugged into a Chang (CLS 9600)power conditioner which plugs into a separate 20 amp dedicated circuit. The rest of the system is a Denon CD player (DCD-1650), ARC LS3 or Cary SLP88 preamp. I also have a VPI table and ARC PH3 phono stage, but they have been removed from the system while I try to figure this out. Right now the only way I can get rid of the hum and noise is to use a cheater plug on the preamp (either preamp)and flip the switches to float the ground on the Brystons. I am baffled as to why I would have to float all of the 3-prong plugs instead of either the preamp or the amps. I should also mention that this same problem exist when I put my spare Hafler amp (9505) in the system. I don't think the problem is the equipment. Any advise is appreciated. Thanks, Scott
jdt332

Showing 1 response by ckoffend

ckoffend
684 posts
 
May not be your solution, but something I found interesting in a similar circumstance. We have a three way light (dim, medium, regular/bright) in the same room as my system, different outlet/different circuit. My wife put a standard light bulb in this lamp (vs. a 3-way light bulb). Whenever the lamp was turned on to anything less than full/regular/bright, I got a buzz through my amp.

Once we put one of those small flouresent lights into a overhead light that had a dimmer connected, whenever it was set to dim (even very slightly) it results in audible issues.

Not sure if either may be an issue in your case, but thought I would share this experience FWIW.
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