I use Mdk9.2 and I have an MSI K7 motherboard with a Hercules Muse 5.1 useing the CM8738 driver and Logitech 5.1 speakers. I have a lot of noise being transmitted by my speakers, such as ; when I scroll with my mouse wheel; my hard drive or cd-rom spools up, and when the case fan is running. I suppose that the sound is not bad enough to suggest that the snd-card is bad but at high volumes when nothing is playing it can be rather annoying to listen to. I can actually hear the voltage changes. Anyone know of anything I can try other that reducing the volume to a reasonable level

Change your speakers!
Normaly this is a problem of bad filtering of mains noise, once I bought some low cost speakers that had this problem. The only other solution is to connect the power supply cord of the speakers to a filtered mains plug, by I gess that it will be more expensive to buy a mains filter then to buy new pair of reasonable quality speakers...
Greets
Pedro

hi,

suggestions -

open up a mixer app (eg, KMix), and mute all unused inputs. with my soundcard, i found the microphone input was particularly prone to picking up crud buzzing around, even with nothing connected..

i would also suggest that you check mixer volumes on the other inputs that you do use. as a starting point, try taking input volumes up to near maximum, then use the volume control on your speakers / external amp to control overall sound level.. this should keep signal-noise ratio reasonable. but you might need to play around with this.

one other suggestion - your cd-rom drive will probably have a length of audio cable running from it to your motherboard / soundcard. many linux cd playing apps require this cable (but some, such as the audio cd player in xine, do not), so i'd advise against removing it, but you might try re-routing it inside the box, to see if noise can be minimised (the inside of a computer case is quite a harsh environment for analogue signals!!!)

hope this helps..

You were right about the mixer, I guess I was trying to get to complicated.
Thanks