[Backwardsman]

Get a Corsair or BeQuiet! Dark-Power powersupply and then you will have a real good and quiet supply. Also, if you have a mic input on your sound-card, make sure to disable it.

 

[Arctia]

Quote:

Thanks for the tip - I had no idea. I'm glad that the PCP&C supply I picked up about five years ago is still going strong.

Who is building a good supply today? Getting into audio took me out of the computer market. One of the boxes is a 2.0GHz Athlon64, single core. It runs well, but am thinking about putting something newer in there.

I still have my PCP&C from three years ago. If they aren't DOA, then they last for years. Great stuff.
 
Generally you can't go wrong with anything from Antec, Corsair, Seasonic, or Silverstone. Other big brands like Thermaltake, OCZ, Coolermaster are iffy. Those power supplies depend on which line they used. Take OCZ for example, it's fine when it works, but out of the box failure rate was abnormally high for their stealthxstream series. ModxStream though was much better.

 

[silverxxx]

I had the exact same problem, and yes, the noises were just like a hdd/ cpu. Turned out to be earth loop, i used an earth breaker in the amp (http://sound.westhost.com/earthing.htm), which fixed that amp. Now i have a new amp without earth and it is clear too. The computer was not modified.

 

[PointyFox]

I used a ground loop isolator on the RCA cables and still had the buzz.  Then I tried it connected to an iPod running on battery.  No buzz.  Therefore I'd think the problem is EMI entering the signal before it leaves my computer.  The only "fix" I can think of is to not use my computer for audio.

 

[silverxxx]

I would agree with you but i do not know what the ground loop isolator was wired like. If the signal is in the computer, plugging headphones strait in the soundcard should have these "artifacts". A ground loop could be found by unplugging the amp power while on, the caps should keep it running for a few seconds, hopefully. Pretty dodgy method though.

 

[ninjikiran]

Its not the items plugged in, I mean straight out of my sound card I don't get any interference/clicks of buzzing.  I have one of those high power consuming GTX295's as well.  Over Spdif out of my sound card, and USB from my DAC(really bad USB implementation mind you) no clicks. 
 
Could be a poorly designed motherboard as well~ if it were case fans simply disconnecting all of them for testing purposes would prove that theory.  At the same time a bad power supply could cause multitudes of issues.  Even if it works, doesn't mean its working at 100%.  For example you can still run a video card off a power supply that has essentially gone bad but you might notice performance issues.
 
Another issue could be buffer size~ raising it might solve your problem since the issues sound slightly similar.
 
edit: Seems the problem was already fixed.