Hi There,
I notice you are using a Cooler Master Cosmos ii Case, I too own a R4BE with the same case as you. The issue your describing is something I also encountered and is not the boards fault. The issue lies with the front panel connections themselves, the front upper connections (Audio Out/Mic/USB3/2 x USB2.0) are all moulded into one plastic block, and the bottom row are also moulded into a plastic block. Inside the block is a Ground Wire, which grounds all the connections Horizontally, back to the chassis of the case. Same with the bottom row. The problem is: Audio picks up data noise from the USB 3.0 and/or USB2.0 ports. So the only solution to solving this completely is to cut out a small section of the block, in between the audio connectors and the first USB 3.0 port and cut out part of the ground wire, which is a small brown wire. Unfortunately - you cannot just unscrew the ground harness from the case either, as the issue is still there because the Audio is still Grounded to the USB ports. The whole process is actually quite easy, and my audio is completely quite now!
🙂 I found a guide from this site which I followed:
http://www.overclock.net/t/1325668/cosmos-ii-front-panel-audio-noise-fixThe only thing I did slightly different - On picture 4, I didn't cut the whole connector in to two pieces because I believe this might have caused mounting issues when re-assembling. I just simply cut out the bottom square using a sharp knife, and about halfway into the block you will see some clear plastic inside, and the brown grounding wire.
Problem solved!
On my Sennheiser HD650 headphones, driving through the front Audio Output. The on-board soundcard actually drives these better than my older Creative Xi-Fi Elite Pro!
Obviously this is temporary whilst I source a DAC and Headphone Amp.
Well Good Luck To Anyone Out There Looking To Perform This Mod!
Thanks
Mike
