Recently I rebuilt my PC - bitfenix Merc Alpha case, gigabyte GA-F2A75M board, AMD A5800 chip and pretty standard DVD-Writer. 

There is interference noise bleeding into the sound.

Regardless of whether I use front or read 3.5" sound out, or sound out via a USB dongle, there is noise.

I've relocated the transceiver from the wireless keyboard (Logitech variety), and that's made little or no difference.

The power supply is new but no-name brand.

So I'm left wondering where's the next step? it bugs me to hear it.