1. Open the TBS Pro Series programs group. 
2. Double-click on the Audio Mixer.  You will see two rows of sliders. 
   The top row is for Playback, and the bottom row is for Recording.
3. In the bottom row on the right, beneath the S/PDIF slider, there is a 
   small button with a red triangle on it.  Click this button to illuminate 
   it.  This will select the S/PDIF - any signal that goes to the digital 
   connection (for example, from a DAT) will be recorded.