Buzzing in monitors, but it is from the PC! SOLVED!

[Amberwolf]

1 minute ago, hockeyjx said:

I ended up trying two different brand mini-computers "as is" with all the same cords, and there was no noise. I can't help to think it is somehow the PC. But this weekend, I will throw variables in.

Do the mini pc's use two pronged ac adapter cords?  Or do they use a 3 prong cord directly to the back of the pc case (no external ac adapter block)?

[hockeyjx]

16 hours ago, Amberwolf said:

Do the mini pc's use two pronged ac adapter cords?  Or do they use a 3 prong cord directly to the back of the pc case (no external ac adapter block)?

The mini pc's have 2 prong adapters. I CAN use a 3 prong for one of the nucs, so I'll add that to the list for this weekend's test.

Edited July 31 by hockeyjx

[Amberwolf]

Well, the point was that if you are using 2-prong wall connnections, then you probably won't experience the issue with them, beause the problem is probably a ground loop via the third pin on the regular comptuer's ac cord.  (since the problem went away when you used a two prong adapter for it).

 

So ther'es something in the grounding of the overall electrical system, probably of the room itself, that is likely the root cause. 

 

Could be in the pc itself, but it "takes two to tango" for msot of the ground loop problems I've run across so something else at the audio end would also be involved. 

Edited August 1 by Amberwolf