Universal players and SACD-PCM conversion (1 Viewer)

[AustinKW]

Steve,

The 49TXi does indeed "downconvert" the 47Ai's DSD stream to 88.2k/32bit PCM for BM/TA/MCACC. Native DSD processing DSPs were not available at the time Pioneer was designing the duo. They are now.

Austin

 

[Ian Montgomerie]

Technology for bass management in the DSD domain is new, expensive and difficult to work with, and limited to very basic functions (bass redirection, time alignment, and level gain sure, but virtually no other DSP effects whatsoever). For these reasons, most manufacturers of SACD decoders have chosen not to work with it. Instead, the signal is converted to PCM to run DSP effects on, and then optionally converted back to DSD for output to a DSD DAC. Converting back to DSD is useless in terms of sound quality, but is done for marketing reasons so that the product can claim DSD output. Sony does have DSD bass management technology, but it's not used in all their chips. Those that use PCM for bass management sometimes have a "direct DSD" mode, where if all bass management is deactivated, the signal is straight DSD. This mode is basically present for magazine reviews. Other manufacturers just choose to use PCM output only, since the assumption is that most customers will want bass management, and if you're converting to PCM, might as well convert to 176.4 KHz and send the output to a PCM DAC.

 

[Jeff Brooks]

This is all so new to me; but, to go back to the time alignment issue, I just connected my Denon DVD-2900 last night, and on the configuration, it specifically states that the time alignment is for DVD-A, and not the SACD. (I'm not sure my ears can tell the difference, anyway.)

 

[Kevin C Brown]

Ian- I don't know if your info is up to date. Pioneer has specifically stated that the 45a and 47ai do not convert the DSD SACD signal at any point to PCM for anything. Their 1st universal player did, that $10,000 machine (the one even before the 47a), and the new cheap 565 or something will too. But not the 47a, 45a, or 47ai. They latter all use Sony DSD chips.

 

[Steve_AS]

Those that use PCM for bass management sometimes have a "direct DSD" mode, where if all bass management is deactivated, the signal is straight DSD. This mode is basically present for magazine reviews. Other manufacturers just choose to use PCM output only, since the assumption is that most customers will want bass management, and if you're converting to PCM, might as well convert to 176.4 KHz and send the output to a PCM DAC.

I anticipate with amusement the reviews in *certain* magazines that will inevitably report an 'amazing' or 'breathtaking' difference between machines with pure DSD signal paths and those using the DSD-->176.4 KHZ -->PCM DAC paths for BM.

 

[Steve_AS]

The 49TXi does indeed "downconvert" the 47Ai's DSD stream to 88.2k/32bit PCM for BM/TA/MCACC. Native DSD processing DSPs were not available at the time Pioneer was designing the duo. They are now.

What's 'MCACC'?

Regarding the rest, my understanding is the the 45/47 series both do 'native' DSD BM of SACD, but cannot do time alignment for that source (which itself supports the claim that there *isn't* a PCM conversion going on, becuase otherwise time alignment *would* likely be doable). But obviously there's lots of conflicting info floating about on this matter, and I'm finding the debate interesting.

 

[Craig_Kg]

So does anyone know about the Philips 963SA and whether it outputs as DSD->PCM, does the DSD->PCM->DSD or has a PCM bypass mode if bass management is not enabled?

 

[ManW_TheUncool]

There is someone over on AVSforum who claimed to have inside info that the Philips 963sa uses 26-bit/354Khz PCM for BM/time alignment/level adjustment processing. He also wrote that it bypasses the conversion when not using any of that processing. I believe you can find his posts somewhere around pages 55-60 in that huge long thread over there. I might've posted the link to his posts over here at some point, but I'm not sure.

_Man_