Nice i got it working finally. Let me explain how. So the most channels are allready assigned (as given in a picture above). The only slot to choose is the master rec out, which is situated in usb 9 and 10. I crated a new Stereo BUS and assigned these two on left and right. So now i can record any channel pitched into the master.
To assign the master out u have to choose a channel on your DJM 900 and switch the upper assgin knob to the usb (A or B). I my case i picked channel 4. The driver says its USB Out 7 and 8 . I assigned it and it works.
