[linux-audio-user] Re: The famous "Jack Hum" (Can't record and desparate)

[Lee Revell]

On Sun, 2006-11-12 at 21:29 +0100, Carlo Capocasa wrote:
> > But the most intriguing part of the whole story: Not only did the noise 
> > get louder at a lower latency, it also seemed to precisely double its 
> > frequency when running at halve the number of frames. I even tried to 
> > measure the frequency of the noise. As far as I remember, when running 
> > jack for instance at 44100Hz, periodsize 32, the noise was at exactly 
> > 44100/32 = 1378Hz!
> 
> That is absolutely fascinating. I WILL investigate this; if it
> coincides, we have a VERY strong case that this is the same problem. 

Really sounds like you have a singing capacitor.  IOW your problem is
cheap hardware.  If this is the case, you won't be able to fix it.

Lee