I've just recently upgraded to nice multimedia speakers and have noticed a clicking noise when no audio is being played. This is volume dependent and increases as the hardware or software volume is increased. I probably didn't notice this before because my speakers were not very good. Anyways, I've got an Audiotrak Prodigy 7.1 sound card as well. So, in a desperate attempt to figure out the source of the clicking noise, I was thinking maybe the PWM of the fan controller was affecting things (for lack of a better way of putting it). So when I turn LCDC off with start/stop setting at 100% the noise goes away, and slowly becomes louder when I turn it on again and the PWM takes progressive effect and brings fan speeds down to 15%.
Not sure it matters, but I've also got temp monitoring going on with the Dallas one-wire's. PWM control is based on temp monitored by one of these hooked up to monitor water temperature in a water cooled system.
So ... anyone with any ideas?
Oh, another thing ... I've rigged up a 100uF cap to smooth the square PWM waveform to reduce stutter to each of the three fan circuits. I'm not sure if this is causing a problem, but I've not disconnected them as yet as a test.
Thank you for your input.
Audio problems with MX2?
Try disconnect the CDROM audio cables from the sound card i had a similar problem, turned out them cheap audio cables to the card was the source of my problems, if that doesnt work, disconnect all inputs to the card (Maybe one of the cables is poorly screened), this possibly can help narrow the problem down 
I know also Namechangecow had a similar problem, not sure what the outcome of his problem was.
I know also Namechangecow had a similar problem, not sure what the outcome of his problem was.
Thanks guys!!!
That was fast ...
Anyways ... pOssEssEd ... don't have the audio cables hooked up ... So that's not the problem. There are no inputs to the card as of yet.
VJ ... you hit the nail on the head ... I muted the inputs and the clicking is gone! Now I just wonder if the clicking will get recorded when an input is not muted. Well, since I rarely record this shouldn't be too much of a problem, but trial and error will tell. The fan wires are all over the place but not very close at all to the soundcard ... maybe the closest place is at the very back of the case where they pass by the back of the card but are still 5cm's away.
I'm grateful for all your help! Still, I wonder why the clicking is there in the first place when PWM is in effect and not when it is not. Seems to me I wouldn't be having this problem if I didn't have this PWM controller. Then again, my case would be somewhat louder.
That was fast ...
Anyways ... pOssEssEd ... don't have the audio cables hooked up ... So that's not the problem. There are no inputs to the card as of yet.
VJ ... you hit the nail on the head ... I muted the inputs and the clicking is gone! Now I just wonder if the clicking will get recorded when an input is not muted. Well, since I rarely record this shouldn't be too much of a problem, but trial and error will tell. The fan wires are all over the place but not very close at all to the soundcard ... maybe the closest place is at the very back of the case where they pass by the back of the card but are still 5cm's away.
I'm grateful for all your help! Still, I wonder why the clicking is there in the first place when PWM is in effect and not when it is not. Seems to me I wouldn't be having this problem if I didn't have this PWM controller. Then again, my case would be somewhat louder.
Not necessarily, but it could happen... (read on)dipan wrote:Thanks guys!!!
VJ ... you hit the nail on the head ... I muted the inputs and the clicking is gone! Now I just wonder if the clicking will get recorded when an input is not muted. Well, since I rarely record this shouldn't be too much of a problem, but trial and error will tell.
The problem is interference.Still, I wonder why the clicking is there in the first place when PWM is in effect and not when it is not. Seems to me I wouldn't be having this problem if I didn't have this PWM controller. Then again, my case would be somewhat louder.
With the PWM not in effect, the current and voltage on the fanwire remain constant (and therefore the electric field around it constant). When PWM is in effect, there is an alternation between on and off; this generates changes in the electrical field. The audio circuits on the soundcard (which usually are not good insulated) pick up these changes as if they were antennas.And if a line in or mic in picks it up, then this distortion is amplified ...
Now, the reason I said it is not necessary that these will be reflected in recordings, is that when you record there will be a signal on the audio connections (e.g. on the line in) and therefore also an electrical field around this wire. This results in the wire being a worse antenna, thus making it harder to pick up a signal.
It can become audible in silent parts of the music you are recording, but that depends on a number of factors (my guess would be that the clicking would be much less prominent). You'd have to experiment with it...
(all in all, a computer case is a bad place for audio equipment: lots of electrical conductors which are badly isolated
)J