Humming speakers

[Sylph-DS]

Hey, I figured there'd be at least some people here that know a thing or two about hi-fi, so I thought I'd ask here.

So, I have a Gigabyte GA-M57SLI-S4 motherboard with onboard HD audio, and I connected my JVC Stereo Set to it through a simple stereo mini-jack to dual RCA jacks, which all goes pretty well. The only problem is that I hear a slight hum coming from my stereo's speakers when it's connected like this. My dad suggested that turning around the power plug from either the stereo set or the PC would help (something to do with the earthing), but that didn't solve it. I should perhaps note that the PC is properly connected to the earth, but the Stereo Set is not.

I even bought a seperate audio card for my PC (Audigy SE) but this didn't have any effect, besides my wallet being a little less full.

Anybody know how I could solve this? It's really quite annoying, as it also does this when the PC is on standby.

Thanks in advance

[jhhoffma]

Sounds like a ground loop hum. Miniplug-to-RCA connections are notorious for this. First, make sure that your computer is on the same plug as the speakers/receiver, that keeps the loop small and reduces the amount of EMI that gets in the lines. You can also try using a power conditioner/UPS/active surge suppressor device, but they can be expensive.

[[B]]

A ground loop isolator worked wonders with my previous setup.

Example