Cable Box Digital 5.1 converted to Digital Stereo

If you're with Xfinity, the new One boxes do pcm.

There is a product that will convert the bitstream to pcm, but I have no experience nor think it would work well.

However, lookup an article by Frank Van Alstine who I believe used such a product.

Did you try the analog outs from the cable box?

Having the TV on is not so bad. It tells you what is playing.

Oddiofyl- Did you try a co-ax ground isolating transformer between your cable box and the incoming cable feed to see if you can get rid of the ground loop? You can get one cheap at Rat Shack (if they're still open) or in a pinch you can put two of those old 300 ohm to co-ax converters that came w VCRs (remember those?) back to back. Cable feed to coax converter-twin lead to twin lead-coax converter to cable box. If that seems like a good idea and you can't make sense of what I am trying to say, pm me through agon and I can send you a sketch.

However, I agree w Kal that you hit the point of diminishing returns pretty quickly on the audio in the cable feed.

Yeah, I can use the Cable analog outputs, but I thought with a digital output through my Dac I could obtain better sound.
I'll check with Comcast about the Xfinity one box. However, past experience tells me that will be a hassle getting through to someone that's knowledgable.