Mac mini to dac

I am using the iPd remote to control my Mac Mini and iTunes library. I can her h music playing in the ma, but I isn't getting through the USB cord to my dacmagic plus. Help?
Have you selected USB as your audio out in sound control panel in the System Preference screen of the Mac Mini?
Go to system preferences on the mini, select sound, and set the output to the Dac
instead of the internal speaker.
Take look at the OS X guide on my website. It tells you how to select the DAC in System Preferences.