yes, it's the usbpre 1. I found this old post:http://mailman.alsa-project.org/pipermail/alsa-devel/2007-June/001404.html
in which the OP stated he asked for specifications, but probably never received them. I don't think I'm able to write a driver, so i guess i came to a dead end.
Or maybe i should take this as sign i should start studying :)
I already know C programming (and some audio-related electronics), do you have references about driver development for linux and snd-usb? General, "academic" resources would be great. It will probabily take years, but at least i may learn something.