I had the opportunity to test a friends machine and unfortunately these numbers i mentioned above are not universal for the Rpi and have to do with the dac.
The way to find your numbers is find the line of the dac from dmesg.
My dac is:
[ 3.586063] input: HiFimeDIY Audio SA9023 USB Audio as /devices/platform/bcm2708_usb/usb1/1-1/1-1.3/1-1.3:1.0/input/input0
the number i need is: 1-1.3:1.0
so the command in my case will be:
echo -n “1-1.3:1.0” > /sys/bus/usb/drivers/usbhid/unbind