"You can. I would prefer using digital coax (or, better yet, HDMI) to take advantage of the DSP in the processor without encumbering additional A/D/A steps."
I am a bit confused? I thought there were only 2 ways of getting DTS-HD to a receiver...HDMI and multichannel RCA cables??
You say you are hooking it up with a digital cable? So you can use a 75 ohm rca cable (digital) OR Toslink?
And if this is the case and true, why would you use digital RCA over toslink?
Or am I totally misunderstand your post. Are you using multichannel inputs AND IN ADDITION the digital cable for regular DTS (not DTS-HD)