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

From: Karsten Wiese <fzuuzf@email-addr-hidden>
Date: Sun May 30 2010 - 17:06:10 EEST

Am Freitag 28 Mai 2010 schrieb fons@email-addr-hidden:
> On Fri, May 28, 2010 at 08:30:54AM -0700, Niels Mayer wrote:
>
> > Audio ADCs and DACs have three important inputs;
> > the signal input, the voltage reference, and the clock.
> > Noise and interference on the voltage reference causes
> > amplitude modulation, and jitter on the clock causes
> > phase modulation. The resulting modulation products
> > look very similar in the frequency domain. One of the
> > authors once spent several days trying to track down a
> > low-frequency jitter problem, only to find that it was
> > in fact a problem of LF noise on the voltage reference.
>
> You're close. See the extra hint in a previous post.

Sound Card A's DAC and ADC share the same voltage reference,
which has a 100 Hz ripple?

Regards,
Karsten
_______________________________________________
Linux-audio-dev mailing list
Linux-audio-dev@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-dev
Received on Sun May 30 20:15:03 2010

This archive was generated by hypermail 2.1.8 : Sun May 30 2010 - 20:15:03 EEST