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Classe' preamp ground loop hum. Help!

I just bought a Classe CP-60 preamp. When I hooked it up i got a vicious ground loop hum. I mean a wicked hum, like if I was running cheap speakers they would be toast. Checked all outlets on circuit, perfect ground. Disconnected everything but amp, preamp and source. Still ground loop hum. Hooked up Sony TAe9000ES in place of Classe', ground loop hum goes away. Do i just have a defective preamp? Suggestions? Advice?
ignatz
ignatz OP
32 posts
 
Narrod- Forgive my stupidity, but is there any other way to lift the ground on the pre-amp than removing the third prong from the existing power cord or getting a new ungrounded ( two prong)power cord?
sol322
426 posts
 
Ignatz get a "cheater plug" just two ends and yor get ground free + reverse capability for testing..
simply_music
8 posts
 
Ignatz. The easiest way to do that is just go to your walmart, k-mart or home depot and buy a cheap plug-in multi plug for about $3.00 and take a pliers and break the ground on it and plug the unit you want to lift into it but may I suggest that you lift the amp first and if no improvement then the pre but not both and if that works just get a power cord and cut the ground. Now this is all assuming that the noise is there even with the volume is down and in both channels, right? I am a Class A dealer here, you can drop me an e-mail if you would like and if the problem persists and if your dealer can't help.
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