Noise (maybe Ground loop) problem

Red Alert

I have a Yamaha AX396 which powers a set of Mission M33 speakers, and a TOA BA823 (dual cassette with stereo amplifier) which power a small set of wharfedale speakers in another room.

The Yamaha has a CD Player, Tuner, Minidisc, a set of DJ decks and my PC connnected to it.

The "Tape Out" of the yamaha is connected to one of the TOA amp's inputs. The PC is on the "Tape In" of the yamaha. The PC is fitted with two sound cards, one is the onboard VIA one and the other is a Soundblaster Audigy Platinum.

At the moment, I use the Audigy card for games and music play and it's connected to the stereo amp. The onboard VIA card is connected to the inbuilt speakers on my monitor and I use it for MSN sounds and nothing else.

The TOA amplifier has two unused AUX inputs, as I use the Tape expansion input for the stereo sound. What I'd like to do is:

1) Allow the Audigy card's sound to be heard on the second amplifier
2) Connect the VIA card's sound to the AUX input on the second amp that has an automatic override, so i'll hear MSN calls if i'm away from my PC.

Trouble is if I connect anything from the PC to the TOA amplifier I get an annoying hum on the speakers. It happens regardless of which sound card is connected or whether the amp's also connected to my main stereo amp (Yamaha).

Any advice?

ruaneg

had a similar problem myself connecting a dac to a PC. Pretty sure its a ground loop problem. Easy fix is to use optical toslink out on your sound cards. If you dont have this you can buy a turtle beach micro usb card that gives you optical.

Red Alert

great stuff, i'll try that out. The audigy has optical and coax outputs, and the builtin one has optical out, so I think i'll just grab a cheap DAC. Cheers!