[LAD] A little quiz about audio measurements...

[Gabriel M. Beddingfield]

On Fri, 28 May 2010, Veronica Merryfield wrote:

>
>> The 100 Hz (being 2x 50Hz, the power freq. in Italy)
>> suggests that it is probably related to some manner of
>> power supply.  However, I have no theory why we're
>> getting 2x 50Hz (and I think I need one :-)).
>
> The implication has been that the USB audio device is a 
> cheaper device. It is therefore more likely that the 
> device runs from the USB 5 volt line than have a separate 
> power supply, and that 5v line is regulated and therefore 
> less likely to have a power line ripple on it.

Yes, as I go back and read that A was proven by A... it 
could be the power source for either device -- and most 
likely the "cheaper" card A.

-gabriel