Hey chaps, I hope you can help. I finally switched from digital coaxial to 7.1 analogue connections between my HTPC and Processor to take advantage of the new sound formats. Unfortunately the upgrade has introduced a nasty buzzing sound through the speakers. It does not sound like a normal ground loop hum as it changes all the time, as the PC does something or you move the mouse or whatever the sound changes. It is like you 'hear' the processor or HDD working via the speakers. The buzzing continues when switching to another input but stops once the PC is off. I tried running a cable between the PC chassis and the Processor chassis but it was a half arsed attempt and I cannot be sure I really got a good connection, is this worth trying properly or can you suggest anything else? Also worth noting, when connecting via anologue to a 'cheap' 5.1 speaker package in my office I have no noise/interference problems. Many thanks, Adam PS I think that the hum was there with the original digital connection but was much quieter, hardly noticable.