Surge protector + UPS

[Sarra]

So, I'm still fighting occasional buzzing through my headphones. I have an Audio Mixer with 4 inputs, one output, that I used to run both of my computers to one set of headphones (and sometimes I plug other things in, super easy).

 

If I fire up a game that loads my GPU, but doesn't make any sound, I get a buzzing through my headphones. If I turn the volume down on my other computer, the buzzing volume changes with the volume on the mixer.

 

Both computers have their own dedicated UPS, and are both on separate outlets.

 

I did some reading and found a surge protector that has built in noise attenuation, basically caps. https://www.amazon.com/gp/product/B0000513O4/ref=crt_ewc_title_srh_4?ie=UTF8&psc=1&smid=ATVPDKIKX0DER Should I plug the surge protectors into the wall, then the UPS units into the surge protectors, or should I reverse it, have the UPS plugged into the wall, the surge protectors plugged into the UPS, and my PC's plugged into the correct corresponding surge protector?

 

Changing outlets, circuits, and even location of the machines doesn't effect the buzzing, but humidity, temperature, and the GPU load in my gaming machine does. I've got Ferrite suppressors on my audio cables, which helped a little... Worst comes to worst, I can just dial the volume to 0 on the mixer when I play quiet games (Sniper Elite 5, yah).

[Sarra]

17 hours ago, Caroline said:

UPS have caps and chokes already, what are you using?

 

If you've changed outlets and circuits and the noise is still there something must be wrong somewhere in the wiring, that or you're running huge motors in your room.

Do something, remove all the inputs from the mixer but one and use that cable to touch the wall, if you can hear a buzzing then there's a ground fault or damaged wire... somewhere, finding where exactly is the complicated part. Borrow a GFCI extension cord if you can -not worth to buy one just to test something imo- plug your PC into it and touch the case while barefoot, if it keeps tripping that's bad, and if it doesn't trips but causes a tingling sensation that's also bad.

 

I had the same problem with my speakers and when I rewired my whole room (replaced ancient wiring and resurrected 2 dead hidden outlets) it was gone, meaning the cause of it was that old wiring, parts of the insulation were so brittle they disintegrated as I pulled the wires out their respective conduits, plus the ceiling fan was incorrectly wired as well as the lights. So if your house is old you might want have a pro take a look at the wiring and breaker box, find the root of the problem instead of trying to hide it.

 

I run a pair of CyberPower 1500VA units, one is brand new, the other is around a year old. I had a 1250AVR die.

 

I've taken the audio cable and poked the wall, nothing. Same with the floor...

 

There's a chance that I can grab a RTL-SDR, then I might be able to actually track down the source in a more... concrete way. The wiring in this house is old, but from what I've seen, it's really overbuilt (you ever had your fridge compressor kick on while the microwave is running and it dims your lights, or pops a breaker? Yeah, NEVER had that happen here, at all, in any way, shape, or form). I can move the entire setup to another room and it still does it, just different pitch or whatever. Does the proximity of the UPS itself to the desktop castle matter? One machine is case-to-UPS directly, the other one is about an inch away from it.

 

Oh, one point I should make, I don't have circuit breakers, we use old-style screw in fuses. o.o

 

My wiring used to be a rats-nest, but I've managed some of it, and run things in a mostly sensible manner, but I still should put more effort into it and get it actually managed. Maybe get a new desk first, though.

[Sarra]

19 minutes ago, Caroline said:

We don't have a microwave but I get the reference. I'm a queen of overbuilding, went for thicc wiring that matched the original (well, the original was for 110V DC power over a hundred years ago so it wasn't "THE" original) even though it's overkill compared to what most people use for new houses.

 

The proximity of the UPS is irrelevant, mine is close to the PC and isn't causing any trouble, about 2 in between both so there's airflow when the battery kicks in. Cable managing is only for the looks unless you're running multiple high wattage appliances and want to prevent overheating which doesn't seems to be your case.

 

I use fuses as well so it's not like that can cause noise, replacing them is costly and breakers don't offer much advantages over them except you can reset them.

Yeah, the house is wired for 20 amps on the outlets, but the outlets themselves are designed for 15 amps. The wiring isn't perfect, but it's reliable and so far, nothing has needed repaired or replaced.

 

I'll get the RLT-SDR and see if I can find the source of the noise. Might even be something I overlooked, or it could be one of my bits of audio hardware being defective, though I doubt it's that.