In your setup to enjoy Dolby True Hd you have to select Linear Pcm as the option on the PS3 instead of Bitstream because Ps3 is not capable of sending High Resoulution Audio in the bitstream form to an external reciever, whereas if you select Linear Pcm in the Ps3 menu then the Ps3 would decode the high resolution audio within itself and send it over the HDMI to a compatable amp, which can take it as Multichannel PCM over HDMI and In your case your amp is a capable one. Whereas in the other case when you try to send the bitstream signal from PS3 to your amp, what you get is Dolby Digital which is a lossy format in comparison with Dolby True HD. However the newer Generation of Players from the likes of Panasonic, Sony, Pioneer and Samsung are all capable of Bitstreaming HD Audio over HDMI to a compatable Reciever.