Digital input on CP750 from BluRay player

[Marty Brenneis]

I have a multi use theatre with a CP750 as the sound processor.
There is an input from a DSS200 for our DCP shows.
Since we also show things other than DCPs we have a mixer that feeds the analog inputs.
The Blu Ray player has a digital output so I run that to the optical digital 4 input.
All is has been swell for many years and that feed sounds great.
Now we are getting some new blu ray discs that have been "Remastered". The CP750 is not decoding any audio from the digital input when the English Language track is selected. Other languages decode just fine. I have seen this on 3 Blu Ray discs so far. (All were from Lucasfilm shows) The work around has been to use the analog output from the player into the mixer and from there into the CP750. The processor does recognize the Dolby encoding in the stereo tracks and gives us 5.1 from it.
The older version of those BluRay discs work fine through the digital input.

Anyone else seen anything like this out there in the wild?
I'll be doing some more experiments to see what happens if I run the disc in a computer and play from there.

[Marco Giustini]

The CP750 does not decode DTS - I suppose the affected tracks are DTS HD-MA. You have a few choices here
1. Set up the player so it does not play DTS, it will play STEREO though
2. Get a player with 7.1 analogue outputs (they are rare unfortunately) and hook it up to the 6ch input of the 750

You can also get some converters on the market but I found them very unreliable.

[Carsten Kurz]

Also, some players allow to transcode DTS to AC3/DolbyDigital. The idea is to always output AC3/DD, no matter what the disc contains.

[Marty Brenneis]

Thanks for the clues. it is interesting that they processed the main English tracks but left the other language tracks alone.
I knew the collected wisdom here would have a clue.

[Dave Macaulay]

It's common to play a BluRay with the player (as default) set for DTS sound and get excellent sound from the trailers before the feature, as they tend to be only PCM stereo which the 750 will decode with ProLogic. Then silence for the feature, until the player is configured to output PCM or transcoded Dolby Digital. Definitely puzzled me the first time I came across that!