Hello, I have a Denon AVR-3802 hooked up in a 5.1 configuration to my Athena speakers. I have hooked up my Denon to my computer, from the CPU's audio output to the Denon's CD input. This is a new CPU with an integrated sound card. When the CPU is connected to the Denon I get humm. I have tried switching inputs on the Denon, unhooked every other input/output on the Denon so I know this is the culprit. My old CPU did not have this problem. Could it be that my CPU is not grounded? Or a crappy design for the integrated sound card? Your help is greatly appreciated - thank you in advance!!!
I would check the output cord from your computer. Make sure, via close inspection, that this cord does not lay next to, cross or in any way come near any power supply wires/cords. It can pick up humm via inductance. Second thing to check is to install a higher grade computer to receive cord that has ferrite cores at each end. Lastly, check you PCs ground. Insure that the outlet is grouded and that the electrical grounding is good. There is a simple 3 prong test device that you can plug into any 3 prong outlet and LEDs show (by what is lit up and what is not) the current state of the outlet, good ground bad, etc. Also check the outlet for the receiver as well.
I had this buzzing you speak of when I first hooked my PC up to the receiver. I think it disappeared when I re-connected with the PC powered off.
I'd suggest buying a dedicated audio card if you do a lot of streaming from the PC.
I picked up a Chaintech AV-710 card for $20 shipped. I hooked it up with optical, and used a software tweak to have the PC output at 44.1Khz without any sampling. The results were a 100% improvement over my Soundmax onboard card.