INTERACT FORUM
More => Old Versions => JRiver Media Center 25 for Windows => Topic started by: kr4 on June 17, 2019, 09:57:48 am
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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.)
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What happens if you turn off DoP in the ASIO settings so it just outputs native DSD to the DAC?
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What happens if you turn off DoP in the ASIO settings so it just outputs native DSD to the DAC?
Does not work at all since the U-DIO8 will not pass native DSD.
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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.
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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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Bitstreaming has no particular deep meaning for DSD, especially if DoP is being used. Don't attribute too much into that word. All it tells MC to do is to avoid decoding the selected formats.
All "Bitstreaming" is basically just packing of non-PCM data into a PCM-style stream. This applies equally to DoP (where DoP is this sort of packing), or movie audio formats like TrueHD. You could equally wrap such a movie audio format into a PCM stream, put it in a file, and play it as if it were PCM, and it would probably work.
"Native" DSD is actually the only exception, since it uses ASIO interfaces to directly communicate the non-PCM DSD data to the driver, without additional wrapping.
For the issue at hand, this seems like a shortcoming in the DAC, doesn't it? If it detects a 5 channel input, shouldn't it be smart about which channels are in there? I would be surprised if every single player is expected to mess with the DSD signal instead of the DAC just being smart for you.
With PCM, this gets solved by inserting empty channel. One of the key problems in inserting empty DSD channels is the way DSD works, there is no absolute value for a silent stream. In PCM, you just set everything to zero, and its perfectly silent. Such a value does not exist for DSD, what I have seen to generate "DSD silence" is generating a very high frequency noise signal and hoping that the DAC will filter that out completely.
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This goes back to an old discussion of how to handle 3,4,5,6 channel signals. They can either have a .1 channel or not. 4 channel can be 4.0 or 3.1. 6 channel can be 5.1 or 6.0. The DAC has no way to sort out those issues. I think the software is the place to handle it, but it needs additional tags to indicate if a LFE channel is present. The problem is the standards dictate a standard order, which the funky file formats don't always follow. A channel map in the header would help, but that is very unlikely to happen. There is no easy answer. Plus, trying to determine if a channel is totally silent requires looking at the channel for the entire length of the track, something you probably don't want to the DAC to do on the fly.
Software is the most flexible place to handle this, but it is by no means easy and these funky formats are just not very common.
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For the issue at hand, this seems like a shortcoming in the DAC, doesn't it? If it detects a 5 channel input, shouldn't it be smart about which channels are in there? I would be surprised if every single player is expected to mess with the DSD signal instead of the DAC just being smart for you.
For the issue at hand, the interface is not a DAC but a USB-to-AES3 (via I2S) bridge. It has 10 input and 10 output channels but is relatively dumb. It does, however, allow the use of multiple synch-ed stereo DACs for multichannel.
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Software is the most flexible place to handle this, but it is by no means easy and these funky formats are just not very common.
Just not very common? I have thousands. 5.0 is the standard for Classical multichannel recordings as very few are 5.1. Currently, MC fixes this if one simply specifies "5.1 channels" in DSP Studio and uses PCM. Not so for DSD.
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Just not very common? I have thousands. 5.0 is the standard for Classical multichannel recordings as very few are 5.1. Currently, MC fixes this if one simply specifies "5.1 channels" in DSP Studio and uses PCM. Not so for DSD.
Sorry, did not mean to mininize it. The point was simply that there are far more 5.1 disks/files sold than 5.0 disks/files.
I do agree that if MC could basically do the same thing with DSD that it does with PCM that would be a solution to your problem. And, given that bitstreaming is not necessary, there could be a solution, like Roon has found a solution.
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Sorry, did not mean to mininize it. The point was simply that there are far more 5.1 disks/files sold than 5.0 disks/files.
No problem and probably generally true but not if you consider Classical.
A quick check of my NYC NAS shows that I have, overall, about 51,000 DSF/DFF files. Of these, about 22,000 are 5 channel and about 15,000 are 6 channel. The rest are 2, 3 or 4 channels.
However, for Classical only, I have about 35,000 (yes, I prefer Classical). Of these, about 21,000 are 5 channel and about 11,000 are 6 channel. The rest are 2,3 or 4 channels.
Note that the vast majority of the 5 channel DSD/DFF files (21K out of 22K) are Classical and there are nearly twice as many of these as there are of 6 channel files!
My point is that 5 channel recordings are common and not an odd-ball exception for Classical collectors.
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Looking at our code it looks like we already try to expand 5 channel to 5.1 channel during DSD bitstreaming.
We don't have a 6 channel DSD DAC, so are a little stuck.
If anyone has any leads on an affordable unit, please share.
Thanks.
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Looking at our code it looks like we already try to expand 5 channel to 5.1 channel during DSD bitstreaming.
We don't have a 6 channel DSD DAC, so are a little stuck.
If anyone has any leads on an affordable unit, please share.
Thanks.
There are none. The cheapest is the >$3K exaSound e38. The next is the $13K Merging Tech.
But these would not help you because they are USB DACs and, via their ASIO drivers, they handle the channel remapping just fine. This issue is founded on using the miniDSP USB-to-AES3 interface and pushing DSD-DoP through it to a trio of stereo DACs. You should engage Tony Rouget of miniDSP in this if you want to resolve it.
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Would someone having the issue test this DLL:
http://files.jriver.com/temp/in_dsd.7z
You'll need to install the latest (64-bit) build then extract this plugin on top of the one sitting in your plugins folder.
It tries to expand 5 channel DoP to 6 channel. Since we can't test, not sure how it will work.
Thanks for the help.
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Would someone having the issue test this DLL:
http://files.jriver.com/temp/in_dsd.7z
You'll need to install the latest (64-bit) build then extract this plugin on top of the one sitting in your plugins folder.
It tries to expand 5 channel DoP to 6 channel. Since we can't test, not sure how it will work.
Thanks for the help.
I will try it next weekend.
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KR4 and Matt —
Whatever happened with this? I’m building a 4.0 system, hoping to use a UDIO8 with DSD and DoP and would like to avoid anything like what Kal dealt with initially. Did the .dll work and was it integrated into MC? Which version?
Thanks, Alan
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Since this thread has been resurrected without my help, I'll just chime in with this:
We don't have a 6 channel DSD DAC, so are a little stuck.
If anyone has any leads on an affordable unit, please share.
There are none. The cheapest is the >$3K exaSound e38. The next is the $13K Merging Tech.
If you're still interested Matt, there is such a DAC.
The obvious choice is the Okto DAC8 Pro.
https://www.oktoresearch.com/dac8pro.htm
It's an 8-channel DAC, with USB and 4xAES/EBU so it will do what you need. Supports PCM up to 192 kHz / 32 bit, DSD128 or DoP64.
It's a very capable piece of kit, for under 1000 Euros.