Speakers buzzing, no audio after new video card install

I recently purchased a GTX 580 and after installing it and rebooting my computer, once windows fired up I noticed my speakers were making a high pitched noise, along with fluctuating static. Upon further investigation I realized my audio was also not working. Here are some things I have tried to remedy the situation:

- Checked the speakers: They work perfectly on another computer, likewise I still get the noise when I tried a different set of speakers and a set of earbuds in the problem computer

- Tried changing the video card out with the old GTX 460, didn't work

- I have tried uninstalling/reinstalling both audio and video drivers using these instructions (http://www.evga.com/forums/tm.aspx?m=586183&mpage=1) with drive sweeper, again to no success

- I have swapped out PSU's and still get the problem

- I have tried doing a fresh windows install with a spare HDD and I still get the noise as soon as windows boots

I have figured out that if I go in to Device Manager, under System Devices and disable one of the 'High Definition Audio Controller' (there are two, but the other is associated with my video card) then the noise will stop.

At this point I am pretty perplexed as to what is causing this. Could something on my board have been zapped? I'm out of ideas for a fix, any help/ideas would be greatly appreciated!

ASUS x58 Sabertooth mobo
Intel i7-950 Bloomfield 3.06GHz Quad Core
EVGA GTX 580
8GB Corsair Vengeance DDR3 RAM
Kingston SV100 64GB SSD
WD Black 1TB 7200RPM HDD
Corsair HX850 850 Watt PSU
 
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