US 224 'whine' noise

[deshead]

My US224 has started generating a 'whine'. It's the weirdest thing: it only happens when I run software that generates sound. Sonar mostly, though it's also present when I play a file with WMP or Winamp.

Some other perplexing details:
- The pitch of the whine seems to be exactly 1Khz. (Maybe 1024Hz?)
- The software doesn’t need to be sending an output signal. If I press “play” in WMP, and turn the volume down or pause, the whine's still there. (It disappears when I press 'stop' though.)
- I have tried unplugging everything but the USB cable from the US224.
- None of the controls on the US224 affect the whine. The fader positions are irrelevant, and even when I have the line-out knob turned to zero, the whine continues at the same pitch and volume (as long as WMP or whatever is still active.)

That last point suggests to me that it's some kind of interference. And I did just get my new Wharfedales (thanks Deepwater.) But even if I remove the new speakers from the chain, and move the US224 across the room, I can hear the whine in headphones or the old mix-checking PC speakers. So maybe it's a grounding/dirty power issue? But then, why would the whine disappear when my computer stops trying to send audio?

I'm stumped. Has anyone had a similar experience?

Thanks
-Des

 

[bigwillz24]

any thunderstorms in your area lately?

Reason i ask is cause i had a similar problem with a 428 after a storm knocked the lights off. Had to send it in to be fixed cause one of the capacitors was blown.

 

[deshead]

any thunderstorms in your area lately?

Crap, yeah, there have been ... bummer.

Thanks for the response.

-Des