Re: DTS MA DD TruHD and BDP-S550
I saw that in the manual too. All I can tell you is that the player has a really nifty "Display" feature on the remote which tells you among other things what audio codec the player is transmitting. When I have the BD Audio Setting set to "Mix", the Display function says it is transmitting plain Jane DTS. When set to "Direct", it transmits Master Audio over bitstream.
Yes the manual does list DTS-Master Audio - but my experience is that it only does it over bitstream and does not have an internal decoder. I'd love to be proven wrong on this. It's a real disappointment if you bought the 550 for its analog connections (it has 7.1 whereas the 350 only has 2) hoping that you could use the internal decoder for Master Audio only to find it didn't have one, but my testing described above suggests that it doesn't.