2. amps-preamps
  3. 1236409165

Strange ground loop...?

Hey,

I just hooked up a new amp and I'm having a strange noise issue. Only in my right channel, I get this high-pitched whine... maybe around 2khz. My left channel is dead silent.

The problem seems to be an interaction between my DAC and my amp. If the DAC is off, the amp is silent.

The amp is an 84' yamaha, so the cord has no ground. There is a ground screw, though, and I have connected that to my power conditioner, hoping this would solve it... nope.

I've tried plugging the amp straight into the same outlet that the power conditioner is plugged into (into which the DAC is plugged in). That actually did work... but I don't want to run my amp straight into the wall.

I suspect I just need to find a proper place to run that ground wire...

Any ideas?
djembeplay
kijanki's avatar
kijanki
3,575 posts
 
Bob - It makes sense, but why reversing interconnects makes difference? If it's BlueJeans then it's grounded on both ends and reversing it would not make any difference. He says that in one configuration of ICs noise is gone.

Why is it only in one channel - ground loop should affect both channels. Something is fishy here. Could it be defective cable? He mentioned that switching to Monster Cables eliminated noise completely.
djembeplay OP
169 posts
 
Ok, test complete. Yes, this is essentially the same test as when I swapped one cable out for the Monster cable.

The result was the same. There is no distortion. The bass is clean and there is no hint of any "whiny" interference noise as I change the volume.

It's like whenever two LC-1 cables are used in tangent, this is the formula for opening the gates of hell...
jea48
2,944 posts
 

The problem seems to be an interaction between my DAC and my amp. If the DAC is off, the amp is silent.
Djembeplay
Bob going back to this statement of Djembeplay.
If it was a ground loop hum problem wouldn't the hum still be present with the DAC turned off?
djembeplay OP
169 posts
 
WAIT! NO! I was mistaken. Upon closer listening, I do still have some distortion in my right channel... right channel only. And this is only with lower frequencies.

The 'whine' sound is certainly gone though.
djembeplay OP
169 posts
 
Ok, so... now I'm going to bypass my pre-amp all together and run straight into my amp from my DAC via a 2ft LC-1 cable.
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