dolby digital to pcm stereo to coaxial dig outpu

I have a unique problem I've never encountered: the Motorola DCT6200 HD cable receiver, apparently, has no way to switch the digital processing so that only PCM stereo is outputted to the digital outputs. If PCM is the source then that is what comes out. I have scoured the Motorola manuals with no success; the cable carrier, Comcast, is a black hole of uselessness on technical questions such as this.

I am looking to acquire a processor that will take a dolby digital signal into its digital coaxial inputs and output the signal as a PCM stereo 44.1 khz via its coaxial digital outs so I can then run the signal into an external Audio Note DAC.

Am looking at a used B&K avp 3090 which looks like it may do as I require. I know dolby digital units will mix down to a stereo output but that is in analogue and not digital output is my experience.

open to suggestions....prefer basic processor but receiver is fine, too. Budget is 750 or less as this is something that will not be used often in my Lowther based system.
Had a similar issue with Comcast. My horrible solution was a Ratshack A/D converter, running the stereo output into that and then into my digital preamp--had huge problems with the threshold trigger on that thing... during low passages, it would stop feeding PCM, which meant my processor had to relock when the quiet passage ended. Better solution was getting an ART DI/O and doing roughly the same thing. Quality from the audio out of my cable box, obviously, wasn't paramount.

Best solution was getting a different CATV box that could be set to PCM output. That is what works for me now...
your box dont let you choose it thu the menu,i had proplems to and had to do it thru the menu,mine was under audio out...i also can only use the output for digital channels only,so i got a good pair of interconnects and ran to my pre its ok..this may not help ,but upgrade power cord and interconnects and thats about it,i did put mine on a line channel never sounded better
there is no menu selection for pcm output and downconversion as with my direct tv receiver....most dvd players have such a feature and I've already set my dvd player for that mode...motorola says enjoy the dolby other words, SOL