It is with a heavy heart, i feel the need to add this to my last post, containing a few pointers to get the card working at all in Linux...
I've had a bad linux-sound-day since i posted. After some random unrelated reboot, it all stopped working. No sound... Alsa saw the card, but the "systray" applet only could use the microphone. In the 'pavucontrol'/Configuration i could not select a fullduplex profile, and i've wasted hours on it. It literally pains me to say the "solution" turned out to be plugging it into another USB port... )-:
(In my case, it went from usb3 to usb2, but i'm not diving any deeper into this than i absolutely have to, for now...!)