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Multichannel over DoP

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kr4:
I run the output of MC to a miniDSP U-DIO8 and its 3 AES3 outputs to a trio of Mytek Brooklyn DACs using the miniDSP ASIO.  I can play multichannel FLAC/PCM in 5.1 but when I try to play DSD output over DoP only the first 4 channels play DSD64 while channels 5-6 play 24/197.4 noise.  Any  ideas?

(The output hardware/software is capable of this as I can play DSD64 in 5.1 via Roon without any external manipulation.)

Matt:
What happens if you turn off DoP in the ASIO settings so it just outputs native DSD to the DAC?

kr4:

--- Quote from: Matt on June 17, 2019, 10:04:42 am ---What happens if you turn off DoP in the ASIO settings so it just outputs native DSD to the DAC?

--- End quote ---
Does not work at all since the U-DIO8 will not pass native DSD. 

kr4:
I have resolved this issue with the help of Jim Hillegass and miniDSP's Tony Rouget. 

It turns out that, despite the multitude of options and variables, the critical factor is the number of channels on the recording.   If there are 6 channels, all's well in PCM and in DSD-DoP.  If there are only 5 channels, i.e., there is no LFE signal on channel 3 of a 6 (5.1) channel.  With PCM and specifying "5.1 channels" in output, MC successfully remaps the channels by inserting a silent channel 3.    With DSD Bitstreaming, of course, DSP Studio operations are bypassed and the output from a 5 channel file, regardless of output settings, results in the SL going to the subwoofer, SR going to the SL and the SR speaker being silent.  Asking MC to convert DSD to PCM fixes the channel layout.

Unfortunately, the vast majority of Classical multichannel SACD releases are in 5.0, not 5.1.  For all of these, PCM conversion (or a native DSD-capable DAC) is necessary.

Considering my ancient experience with such 5.0 dscs in the past, it is a bit embarrassing that I did not recognize this sooner.  Duh.

dtc:
I have never really understood why "bitstreaming" was necessary. As long as all DSPs are off and there is nothing else changing the output (like dithering), then a bit perfect output of the PCM format with DoP encoding should be fine.  Straight MC output is bit perfect, whether it is 2 channel or 6 channel.  So DoP should work without bitstreaming, unless bitstreaming is doing something else to force bit perfect output.  If so, the remapping needed to make 5 channel work should be possible, unless I am missing something.

EDIT:  I have a 2x DSD file (2 channel only) that is stored in DoP format. That is, it is a flac file with the DoP format for  the 2x DSD in it.  It plays fine with DSPs turned off. That confirms to me that bitstreaming is not needed when using DoP.  That means it should be possible to have MC create a DoP file for a 5 channel DSD with the appropriate channel mapping, much like it does with a normal PCM file. It would require changes to MC, but it should be possible.

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