Dominic Sacré wrote: > On Friday 06 of November 2009 19:55:25 Martin Homuth-Rosemann wrote: >> you're right - the pcm2902 codec is broken by design. The internal >> voltage reference shows a terrible distortion because the 1 kHz usb >> clock isn't decoupled properly. The data sheet >> (http://focus.ti.com/lit/ds/symlink/pcm2902.pdf) recommends the use >> of an external voltage reference for "a high-performance application" >> (figure 37) - unfortunately Behringer uses the circuit for "a simple >> application" (like figure 39). >> I tested my UCA202 with Fons' jaaa and got a "nice" peak at 1 kHz - >> it went away after adding a REG103-A to my UCA (you can get free >> samples from TI). > > Hi Martin, > > How do you "add" a REG103-A? Do I need a deep knowledge of electronics, > or would a soldering iron be enough? ;) > > I've got a UCA202 which causes a very audible, pulsating noise at > multiples of 1 kHz while running Jack. If there's a way to fix it, I'd > like to try. Of course the device was cheap, and as it is it's pretty > much useless to me, so I'm not all too afraid of breaking it... Strange, I've got a UCA202 that doesn't have any such noise at all. I used to get noises when I had it plugged in via a self-powered external USB hub. -- David gnome@xxxxxxxxxxxxx authenticity, honesty, community _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
