Maybe, pick up a used Oppo BDP-83, and use the analog outs into the 5001? That way, you can get both Dolby TrueHD and DTS Master Audio HD. But, you will need all the analog interconnects, which may cost enough to be a nice chunk towards a new receiver!
And, with the Oppo, you can play SACD and DVD-Audio discs, if you like.
Also, somebody correct me if I am wrong, but just because you are seeing "PCM" on your 5001 doesn't necessarily mean you are hearing DTS Master AudioHD. The 5001 may be defaulting to the next level lower of DTS.