As title said, I connect ifi idsd black USB DAC to my Pioneer xdp-100r. But spotify didn't output PCM (or any audio) to USB DAC.
I don't see there is any option in Spotify that I can swtich audio device.
Thanks for getting in touch with the Spotify Community. We'd like to help.
Can you let us know what Spotify version you're using? Also, does the same thing happen with other music apps?
We'll see what we can suggest, don't worry.