Originally Posted by John Haghighi
Ok so it's all done in the digital realm no DACs, however PCM is processed for SACD on the PS3 with PCM 176 filter (upsampled) before it's sent as LPCM over HDMI so in this case for SACD, the preference would be to send the DSD bitstream over HDMI and let the receiver handle the processing. Not sure if there is any PCM processing going on for the lossless movie soundtracks, but if there is, that could account for differences people are suggesting.
Total apples-to-oranges comparison.
DSD (SACD) has to be converted into high-res PCM because it ISN'T natively PCM like movie soundtracks. DVD-Audio, on the other hand, is high-bitrate PCM. So, yes, for SACD sending the DSD is preferable (if you have one of the receivers that processes it, a rarity these days since most new ones don't). There is a totally different 1-bit (sometimes 2-bit) D/A conversion system for DSD. A very small percentage of homes will have a piece of equipment that does this I wager. The best SACD players are those that either do that DSD conversion internally and use multichannel analog outputs, or pass the DSD to a capable receiver for the conversion. The PS3 (and some SACD players) convert the signal to high bitrate PCM, either to make it more widely accessible, or in some cases so that bass management could be applied. I have a player that did the PCM conversion so it could apply management, but it was at some insanely high resolution and the player still used onboard DACs and analog outputs to my receiver.
Movie soundtracks (at least the ones we have now) start out as PCM audio, and only 48khz, not as high-res as DVD Audio (the idea was to devote all the space of a DVD to audio), nor as high as the PCM tracks created by the PS3 (and some, if not many, non-preferred SACD players) when chewing SACD info.
The PS3 outputs unprocessed PCM from uncompressed tracks and unprocessed PCM from TrueHD once the PCM track is unzipped. There's a lot less trickery to deal with than with the lossy legacy codecs. Indeed some systems can make DD or DTS sound much better than others. Receivers tend to do some processing with those signals to make them sound a lot less lossy, which is why I prefer to have my Pioneer do the work on those, rather than let a player decode them to raw PCM.
From what's been said, any differences people hear between extraction occurring in the PS3 vs. in the receiver could only be attributed to problems with PCM over HDMI (hence all PCM tracks must suffer this to), namely this new "jitter" culprit I'm guessing very few will be able to detect.
Of course there could well be cases of level-matching to deal with as well. If you have to crank your receiver up more with one setup than the other, wouldn't this create differences in sound quality? Could you introduce background hiss (hear there's that whole other can of worms being opened -- adding noise creating the perception of better sound!) by having to overdrive a quieter signal? Conversely, if the signal is overly loud, do you risk underdriving it, impairing sound quality and destroying your speakers (inadequate headroom)?
One would hope that in today's digital realm systems are in place that would ensure the PCM signal is always output at the optimal volume, but that kind of practicality is doubtful isn't it?