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

[Fons Adriaensen]

On Mon, Nov 13, 2006 at 06:14:35PM +0100, Pieter Palmers wrote:

> Some things you can try:
> Disable all power management features and run on full power with lots of 
> load.
> or
> Disable all power management features and fix your cpu speed to the 
> lowest setting.

I'd be surprised if this would turn out to be singing capacitor.
Every switched-mode voltage regulator needs a an inductor, and
these are much more likely to 'sing'. Probably you have a badly 
designed or specified regulator that fails when the load is
below a minimum value (a classic problem with SM regulators).
To test this, load the power supply e.g. via the USB connectors
(a simple USB powered keyboard light could be enough). 
If you can locate the component, and it turns out to be an
inductor, applying a bit of epoxy glue on the winding will
probably silence it.

-- 
FA

Lascia la spina, cogli la rosa.