Once again I’m having horrible sound quality on my PC and spent hours on forums searching for possible resolutions. I checked several software solutions and am convinced now that it is a motherboard or electrical issue. I tried a different outlet across the room, but heard the same noise. I tested the outlets wiring and they seem to be wired correctly.
The noise started very suddenly today after being quiet for a month or so. Even during the boot process, before any drivers can load, there is an odd hissing back and forth in the headphones with odd bloops and beeps now and then. This gets worse after the OS loads (Linux or Windows). Even when sound is muted on the OS, I still hear the hissing and blooping. I did test the headphones on a different device (battery powered) and they work fine. I also tried a much older PC on the same outlet and it only had a very faint rustling sound in the background, leading me to think it is a motherboard issue.
I may try the EB Tech HumX device, but it is around $70, so is an expensive experiment. Even a ground-loop isolator doesn’t change anything (I didn’t really expect it to on headphones).
I also want to get a UPS for the PC to further isolate the power source, but when I went to Amazon to get the one I wanted, the reviews for the last month say that the latest batch of CyberPower units have a terrible strong odor that doesn’t go away. So looks like I get to wait until CyberPower takes charge, forces some quality control on their China factories, and purges these bad units from the market.
In the meantime, I have to record onto a handheld digital recorder and listen to files the same way.