Yamaha receiver - PS3 - bitstream vs l-pcm

[egon_spengler]

Hello everyone! I'm new here. I was recommended here by my brother. I've got a few queries regarding my new 5.1 setup. I'll try to give as much detail as I can.

I'm running:
32" Samsung LCD HDTV (don't know the model off hand)
Yamaha RX-V361 AVR
PS3 60gb @1080i (Video = HDMI, Audio = Optical Out)

Now, I've got my PS3 BD/DVD output through optical set to bitstream and I can watch DVDs and BDs in glorious DD5.1 or DTS5.1. (Note: My anp displays all 5.1 channels active and displays 'Dolby Digital' or DTS) When I watch a bluray (eg Casino Royale) DD5.1 is fine and select uncompressed pcm the sound quality dips dramatically.

If I set the PS3 BD/DVD output to L-PCM and run a bluray it sounds fine and all channels are making some kind of noise. Selecting uncompressed now causes a leap forward into stunning quality sound. Great! However, my amp no longer displays 'Dolby Digital' just Pro Logic II and shows only the L&R channels. It does say 'PCM' on the display and all channels are making sound, however I have not noticed whether it is accurate 5.1 positioning.

Still in L-PCM mode - When trying the THX optimiser on the Terminator 2 BD the L, C & R channels sound okay, but the SL and SR speakers sound together when SR is highlighted on screen and the SL and R speakers sound for the SL channel is highlighted on the screen. The subwoofer does not sound at all. DVDs (despite selecting DD or DTS) are all detected as PLII movie. Switching back to bitstream allows all channels to sound correctly, but uncompressed audio (where available) sounds poor.

Whats happening? Is it the PS3 at fault or the amp? I want to put in a BD/DVD and hear 5.1 perfect and I want my amp to detect the selected output correctly. I also want to be able to use uncompressed audio where I can, but without having to switch PS3 output modes, and I would expect my amp to detect the 5.1 mode, not PLII.

Sorry if I've confused you all, I'm confused myself. A mate said the PS3 can only output L-PCM in 5.1 through a HDMI. Is this correct? I'm in the dark!

Thank you
Matt