Hoping there's some audio and/or electrical people around here...so I use a setup for streaming events that has game console audio running into a hardware mixer, then the mixer being run into my PC's line in. At some point last year I started getting this bit of electrical chatter/interference that I cannot for my life seem to get rid of.
It only happens when my mixer is plugged into my PC. If I plug the mixer into anything else(directly to speakers, etc) I don't hear it. If I plug any other audio source other than the mixer into the PC, I don't hear it. I've tried plugging the mixer into some of my PCI devices to see if it was just the onboard audio that was having the issue, but I hear it when plugged into those as well.
This is what it sounds like: https://soundcloud.com/sassageking/interference
Does anyone recognize this kind of sound? I have heard it may be a ground loop, but to the best of my knowledge I have done most everything I can to not have that happening with the way my setup is, and ground loop isolators seem a little pricey so I didn't want to pay for one without knowing for sure that it would do the trick. Any ideas?