Ok so I have recently hooked up the front panel 3.5mm jacks to my mobo and the audio sounds good that comes out of them but there is also this weird high pitched mumming/buzzing sound in the background. It almost sounds like you can hear the mobo operating. Any thought on how to stop this?
More about :antec 900 front headphone jack making odd sounds
It's a common issue with OB sound. It's feedback from the high frequencies of the computer. The cable stretches along the board in most cases, and according to our electronics engineer here, this is what causes it.
You could try repositioning the cable and try to move it away from the motherboard as much as possible. It happens on my Antec 1200 too.
Only if the noise comes from coupling into the front jack cable. If it comes from noise directly coupling into the sound chip's power supply or outputs directly on the motherboard then there isn't much that can be done about it.
I solved my motherboard's audio noise problem by buying a USB headset, no more noise pickup within the case but the sound output isn't quite as good as the Audigy-2 I had in my previous PC.