30 May
2010
30 May
'10
6:08 p.m.
Am Sonntag 30 Mai 2010 schrieb Karsten Wiese:
Am Freitag 28 Mai 2010 schrieb fons(a)kokkinizita.net:
ah erm, just found "the winners" thread.
On Fri, May 28, 2010 at 08:30:54AM -0700, Niels
Mayer wrote:
Sound Card A's DAC and ADC share the same voltage reference,
which has a 100 Hz ripple? 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.