CCRMA IPL Studio C User Guide
From CCRMA Wiki
IPL Studio C Users Guide
Macintosh: Getting Started
All audio signals from the Macintosh are routed into the the Yamaha DM1000 digital mixer via an optical line out card. You will need to make sure system preferences on the mac are set to the right output, and also that the mixer has the right settings.
Start by getting any kind of a audio signal playing from the mac (I go with pandora or itunes).
Now Look at the mixer. Try selecting Layer Channels 17-32, and raise the first two channel sliders. If that doesn’t work, read on...