USB DAC not recognized

I have a Raspberry Pi 3 running Volimio 2.001. Everything boots up fine and I can play music through the headphone jack on the Pi. However, I haven’t been able to get it to recognize my Schiit Modi Uber dac over USB. I’ve tried setting the dwc_otg.speed=1 and have max_usb_current=1. I’ve tried a powered USB hub and connecting straight to the Pi. Any suggestions on how to get this working?