For the last few years, we've been quietly tolerating a significant amount of noise being output from our HTPC (details in sig). It's most noticeable when it's on but not outputting sound (some static when an HDD spins up etc.), though it is present all the time.

At the moment, we're just using the analogue line out to a high end 1980s vintage stereo amplifier. I'd previously assumed that we'd eventually upgrade the amplifier, and that might solve the problem, but I was wondering if the noise is actually being generated on the MoBo (whereas I'd originally thought it might have been to do with the age of the amp).

I see 4 possible options, in increasing cost order:
* Buy a separate multi-channel soundcard but just take analogue stereo out of that
* Buy a separate stereo soundcard and take analogue out of that, hopefully reducing the noise (downside: stereo soundcard more expensive than multi-channel card)
* Buy a separate DAC, and use digital out from MoBo* Buy a new amp and connect digitally

So I know it might seem semi-heretical, but we'd really be quite happy with just clear stereo output, and not too worried about the complete home theatre experience. We'd prefer to do it cheaply, and rather save pennies for new high-end speakers. This is all assuming that the noise is being introduced in the HTPC, rather than further down the line.

(FYI- have tried swapping out cables and speaker, and grounding amp to HTPC. Should probably have tried a different amp to verify that it is HTPC induced, but haven't done so yet).

Cheers!

[EDIT: Apparently I haven't posted enough for my sig to show anymore; relevant bit:
HTPC: Silverstone LC16-MR Silver, Corsair VX450W PSU, AMD X2 5200+, 2Gb RAM, Gigabyte MA-770 DS3 Mobo, ASUS 9400GT Silent, 1TB Western Digital HDD, 1TB Samsung EcoGreen, 1.5TB WD external; LG DVD Writer, Hauppage HVR2200, Hauppage T-500, 2xArtical Cooling PSD fans]