I normally use my Blackmagic card for sound output on my Mac with Premiere CS6. I want to work with the digital output on my current project but when I try switching to digital out under Preferences>Audio Hardware the audio still comes out of the Blackmagic card but not the digital audio out on the Mac. I'm testing with the bars and tone in the browser and my timeline sequence. FCP 7 works as expected when digital out is selected, and I know digital out is working properly on my computer.
OK, sorry it was that I had to switch audio device under plackback.
Perhaps this should be added to the FAQ under No Sound During Playback, which doesn't include the Preferences>Playback as part of the troubleshooting for MAC.