I asked Andrew of Small Green Computer for a refund or replacement though he did not oblige.
What do I use the firewire port for? Read above and you will see. To recap, I use it to connect an external DAC. The music is output from the PC to the DAC via firewire, and then from DAC to the amp to the speakers.
although it now appears that Intel's USB 3.0 implementation is not 100% back compatible with USB 2.0. Specifically isochronous audio transfer.
Are you absolutely sure that is the cause of the noise? As others have pointed out, that is the PC speaker and it should only make noise if it's supposed to. It would also be very obvious and louder than any electronic whine. Is the noise constant or does it only present after the PC has been on for a while?If the noise is more like electronic whine then the likely suspects are the coils to the left of the speaker in your picture.
When I put my finger on this component, or more specifically, cover the small hole on top of it, the main part of the noise is gone!
Pair of wire snips. Should take you about 8 seconds.
Replace the piezo - you mean replace this particular component (AC-1205G) ?
Wouldn't there be a "gap" in the electrical signal then?