I'm having some trouble trying to achieve a specific setup with my RME UCX on my mac.  I wanted to see if it was possible, and if you could help to guide the setup process for it.  What I would like to achieve is the following:  I am using the UCX with my Mac, and would like to route signal from the SPDIF input of the UCX to the first audio channel seen on my Mac.  The program I am using which needs audio is only grabbing the first 2 channels from the sound card, but I can confirm in TotalMix that it is seeing signal on the SPDIF input channel.  Is there a way in TotalMix that I could route the SPDIF input channel to be the first input channel seen by my Mac OS, or is there a mode of operation in which I set UCX to only use SPDIF (forcing those channels to be first in index)?  I've been able to confirm that if I route my SPDIF input to AN1 output, then with a physical cable route AN1 output to AN1 input, then my program is able to see signal, but obviously I would like to avoid the extra steps & latency from the extra D/A + A/D conversion with this option.