Am Freitag, 6. November 2009 schrieb Arnold Krille: > On Thursday 05 November 2009 23:40:43 Hartmut Noack wrote: > > So again a last try: can anybody recommend any USB-interface recently > > available for about 50 Eur/USD ? > > I was going to recommend the edirol um22 like I own one. But then again you > are probably searching for a usb-audio interface ;-) > > Lets face it: in the 50€ range there is nothing to expect except for > behringer and maybe terratec. Both cheap and noisy as hell. And not really > better then any built-in sound-card. > > Arnold > Arnold, 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). Ciao Martin _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
