My current issue is there seems to be a fairly frequent pop and crackle while using the rear panel audio connectors. Tried using a USB headset and there is no audio distortion as far as I can tell. Leading up to this I had been trying out litecoin mining. Remembering I had an XFX 7850 laying around I figured I would swap my GTX770 out and try running on the 7850 and seeing how it would run. Some where between swapping the cards and changing drivers the audio issues arose. I have tried uninstalling an reinstalling sound card drivers for the on-board audio to no avail. Am I right in assuming the on-board audio is dying out? If so would a cheap PCI sound card be the way to go or should I just replace the board?
So I don't know if this would have anything to do with it, but typically when you install your graphics drivers it also comes with some sort of "hi-def audio" bundled along with the gpu drivers. I know both Nvidia and AMD do this, and I don't really know anything about audio in this regard, but perhaps that's it. Check your device manager and you should see an AMD Hi-def audio device under the audio section. Maybe it just isn't agreeing with your onboard... idk. I've got the same mobo as you and never have had any problem with the onboard audio. Maybe try uninstalling the amd drivers and switching back to your 770 for a bit, if you haven't already.