Cable Box Digital 5.1 converted to Digital Stereo

if your tv has an optical output it will most likely deliver a 24/48k stereo PCM signal to the DAC.....

My Comcast box will only output dolby bitstream, even if I set it to stereo in the main audio menu and in the setup menu that is invoked by pressing menu with the unit off....Comcast had no idea how to help me so fortunately my TV's dac downmixes to stereo pcm. Good luck, maybe you'll talk to a rep that's knowledgeable.

Give the tv optical output a try if so equipped. I am using optical to my NAD M51 dac and tv and netflix have never sounded better.

FYI, I had to go out of the TV rather than the analog out of the cable box.....I had a nasty ground loop hum that only appeared in that config.