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
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Bob - I asked since I've never had coax interconnect. Grounding shield on both ends is really bad, using shield as return is even worse. In addition coax cables, used in video applications, have not the greatest copper since at high frequencies signal travels only on the surface (often silver plated). Blue Jeans cables can still sound great (I don't question that). Capacitance, they are so proud of (12pF/ft) is nothing special (typical for polyethylene) since best cables have 3.5pF/ft and my cable has 5.1pF/ft. In order to get this capacitance foamed teflon in oversized tubes is required but it's expensive.

I am not talking about ground loops. If transmitting end (let say preamp) has ground/case at different potential than power amp's ground/case then it places this potential on the shield. Shield couples this difference (AC) to signal wire (referenced to different GND). When shield is grounded on the amp side then it has exactly the same level as the reference level of the signal wire and doesn't couple anything.
So what alternatives to BlueJeans do you guys think I should try? I need to stay around that same cost, unfortunately ($40 per cable max).
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Djembeplay - I did not read your posts about cables carefully. If it's Blue Jeans cable and is grounded on both ends, like Bob says, then switching cable direction wouldn't make any difference.

It is difficult to find something in this price range (and I don't have a lot of experience). You might be able to find used AQ King Cobra (previously Python). It is very nice and neutral cable.