HDCD and 24/96 DVD Audio (1 Viewer)

[Bob U]

I just started experimenting with both of these. For the record, I have a Toshiba SD3109 and a Parasound AVC-1800 Pre/Proc that is digital only with 24 bit DAC's. In other words, an analog signal sent to the Parasound is digitally encoded, then decoded at the output. A digital signal sent to the Parasound stays digital until the DAC.
I learned on a another board today, that HDCD on the 3109 is only decoded through the analog outputs. Of course, this is not documented in the manual anywhere and when I called Customer Service at Toshiba, they didn't have a clue. But, it makes sense that the Pacific Microsonics chip would be before the analog out. I also understand that HDCD should be set to PCM for the output, though my normal standard is Bitstream for DD and DTS going digital to the Parasound.
So, I experimented. Yes the analog outs sound better, but I hear NO difference between PCM and Bitstream from the analog outs. Should I? Is there something I am missing here?
Similarly, I figured that the 3109 is decoding 24/94 and will send a 24 bit signal out the digital out, so I am using the digital out to the Parasound digital in for this. Is this a correct assumption? And if so, should I be set to Bitstream or PCM for 24/96?
Appreciate your thoughts. This one has me confused.
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[Adam Barratt]

As HDCD processing is performed in the player for output via the analogue RCA outputs, what you set the digital output to will make no difference. The actual digital to analogue conversion is being performed by the Parasound.
I'm not familiar with Toshiba's output configurations, but setting the digital output to either bitstream or PCM should produce exactly the same digital information when playing an HDCD CD (and your comments support this).
The Toshiba will output 24-bit 96kHz material via its analogue outputs, but downsample the digital output (probably to 16-bit 48kHz).
Adam

 

[Bob U]

Thanks, Adam.
I'm pretty sure the Toshiba manual says specifically to set the HDCD output for PCM - I'll double check. But yes, I do not hear a difference.
The Tosh is 24/96, so are you sure it would downsample the dig outs? If so, that would suggest I should use the analog outs for 24/96 even with two stages of decode encode decode. But if not, I would think the better sound would be from the dig out of the Tosh. And then, as Bitstream or PCM?
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[Bob U]

Just found the settings matrix and you are right. The dig out does downsample 24/96 to 16/48. On the 2 ch output jacks and Bitstream set, it downsamples to 20/48. The analog out on the 2 ch jacks is 24/96.
Odd.
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