2012 Mac Mini plays through optical out but not usb.
I have been using this older Mac Mini, 2012 OS 10.15 Catalina as a music server for my digitized music. It worked just fine with a NuPrime DAC through the USB output, but I gave that DAC to my son and have an Anthem STR Integrated Amplifier with built in DAC. The Mac Mini recognizes the device and plays fine through the headphone optical output as digital out. However it will not play through the USB output even though Sound Preferences and Audio Midi, show the choice between digital out and STR Amp. I have tried all 4 USB ports and connected another computer running Catalina which plays fine through the USB input of the amplifier. Any suggestions would be appreciated. I may try reloading the OS in recovery mode, but would appreciate other possibilities. Thank you.
Earlier Mac models