pops and cracks

[Christian Casimir]

Now, that's what I call an proper answer ! ;-) Well, leave me the time 
to test that. I'll be back to you asa I've got some more info to give.

Thanks !

Christian C.


Jan Kokoska a écrit :
> On Fri, 2004-10-15 at 12:36 +0200, Christian Casimir wrote:
> 
>>Hi,
>>
>>
>>I get really annoying pops and cracks, NO MATTER what the volumes are in 
>>the mixer... If I put the volume down, I just get quieter pops and 
>>cracks, but it won't prevent them...
>>
>>Any idea ?
> 
> 
> 1) Check your mixer settings, there should be no channel at max,
> magnifying the noise. Actually I can see you do this already, so maybe
> skip to the second point.
> 
> 2) If your mixer settings are fine, test this with a 2.4 kernel, e.g. in
> Knoppix which has both.
> 
> What magic is that? Well, process scheduling resolution default changed
> from 100 Hz to 1000 Hz between 2.4 and 2.6 (somebody probably can tell
> the precise versions).
> 
> If there is a "signing capacitor" on your board, which might resonate at
> 1 kHz (or actually somewhere else, but 1 kHz being sympathetic frequency
> to that, and unlike 100 Hz, unfortunately audible) you would hear noise
> every time it gets discharged/recharged. Entering power state, checking
> bus, whatever circuit is it in. With 100 Hz the problem is the same,
> except you wouldn't hear it (humans can still sense it at high
> intensity, vibrates in your stomach, not the case with audio
> reproduction unless you have some impressive stage set).
> 
> If this turns out to be the cause (and your hear nothing on 2.4), you
> can recompile 2.6 after editing Hz in include/asm-i386/param.h.
> 
> HTH,
> 
> Jan
> 
>