I have this Turtle Beach Audio Advantage Micro usb sound card, er, stick. Inside it has pretty much nothing but a C-Media CM102S chip. TB claims, as does C-Media, that it can do S/PDIF out, and I believe them based on the glowing red TOSLINK light. :)

I found previous emails on this list (http://www.mail-archive.com/alsa-devel@lists.sourceforge.net/msg09979.html) suggesting that there is probably some magic to be applied to tell usb hardware to go into S/PDIF mode.

I've captured some traces under windows, linked from http://sandeen.net/tbaam/index.html

Specifically, http://sandeen.net/tbaam/2spkr-spdif.txt seems to be a fairly short burst of USB activity when I used the control panel to switch from 2 speaker mode to spdif mode. I see the exact same activity when switching from headphone mode to spdif mode. Strangely, switching from, say, spdif back to 2 speaker seems to generate a lot more traffic. The full annotated trace is here: http://sandeen.net/tbaam/usbsnoop1.txt

In any case, are these traces helpful to anyone who understands how to talk to a C-Media CM102S usb sound card? Does it look possible to poke this hardware into S/PDIF mode with this information?

Thanks,

-Eric