Thank you for the response Sfar! I did as you suggested and yes, USB comes up as an option but no music. The Pop Pulse shows a steady green light when I connect the USB cable from the back of the computer to the Pop Pulse but when music is actually being produced the light should flash. Must be something wrong with my internal USB systems in the iMac since none of the three USB outlets will produce sound. OTOH other USB devices work fine (keyboard for instance).
USB ports do everything except export music
Am I missing something here? My iMac has several USB ports but none of them will allow me to play iTunes/PM through them. The headset/Toslink outlet is the only way I can run music through to my system. A year or so ago I could come out of the iMac USB port into the Pop Pulse and then on to the system via SPDIF. Now that doesn't work.
Maybe there is a setting that I have forgotten about?
Maybe there is a setting that I have forgotten about?