DTS Audio files through S/PDIF interface

[daikonran]

I have some DTS Audio files that I want to actually listen to in their true 5.1 nature, but I don't know how to play them through the S/PDIF interface. I have VLC configured to automatically play through the S/PDIF interface when it's available, and I have it plugged into a 5.1 surround system via an optical audio cable. It still only sends the 5.1 analogue, which my audio system then identifies as being stereo 44.1 kHz.

Suggestions, please?

EDIT: I have been to this topic http://download2.videolan.org/viewtopic.php?f=2&t=8853 but my reciever's speaker indicators blank out when I tried this.