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Author Topic: Multiple identical USB DACs - possible in multichannel setup?  (Read 1511 times)

fitbrit

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Multiple identical USB DACs - possible in multichannel setup?
« on: December 05, 2023, 05:01:54 pm »

I have a bit of a niche question.

A customer of mine wants a VERY high-end multichannel setup, but is unsatisfied with multi-channel DACs. Instead he wants to use multiple stereo DACs for native DSD multichannel surround music processing.
My initial thought was that three SOtM USB cards in the same system going to three physically distinct - but identical model - DACs would work. However, I am not so sure now, as to whether MC would see them as three separate sound devices if they all use the same ASIO driver. Can anyone give any insight in how to achieve this?

I know that the DSD music would (probably?) have to be decoded to PCM to separate the channels to distribute to the appropriate cards first, so native DSD playback would not be possible.
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kr4

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #1 on: December 05, 2023, 08:02:05 pm »

I have a bit of a niche question.

A customer of mine wants a VERY high-end multichannel setup, but is unsatisfied with multi-channel DACs. Instead he wants to use multiple stereo DACs for native DSD multichannel surround music processing.
I think he is misguided. 

Quote
My initial thought was that three SOtM USB cards in the same system going to three physically distinct - but identical model - DACs would work. However, I am not so sure now, as to whether MC would see them as three separate sound devices if they all use the same ASIO driver. Can anyone give any insight in how to achieve this?
(Been there.  Done that.)  This can be done only with a Mac (and not a PC) although I do not recommend it.  The DACs should have the facility to synch their clocks. He should consider the exaSound and Okto 8 channel DACs. I am currently using a Merging Hapi II which technically outstanding and can support even more channels.

Quote
I know that the DSD music would (probably?) have to be decoded to PCM to separate the channels to distribute to the appropriate cards first, so native DSD playback would not be possible.
It is easily accomplished with a multichannel DAC.
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Kal Rubinson
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eve

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #2 on: December 06, 2023, 10:59:09 am »

I have a bit of a niche question.

A customer of mine wants a VERY high-end multichannel setup, but is unsatisfied with multi-channel DACs. Instead he wants to use multiple stereo DACs for native DSD multichannel surround music processing.
My initial thought was that three SOtM USB cards in the same system going to three physically distinct - but identical model - DACs would work. However, I am not so sure now, as to whether MC would see them as three separate sound devices if they all use the same ASIO driver. Can anyone give any insight in how to achieve this?

I know that the DSD music would (probably?) have to be decoded to PCM to separate the channels to distribute to the appropriate cards first, so native DSD playback would not be possible.

USB D/A wont work here.

If he's dead set on multiple stereo D/A units, he'll need to split out AES signals to go to each D/A unit and sync the clocks.
This would be accomplished with an audio interface with the required number of digital outs + word clock out (or slaved to another clock). The audio interface then appears as a single device on the source PC. The audio interface itself could be USB but this way you're not trying to sync up multiple asynchronous USB D/A units.
Additionally, if his desired # of channels is 8 or under, the Okto would be something to look at. Performance / measurement wise it's really top tier.
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fitbrit

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #3 on: December 06, 2023, 04:13:47 pm »

I think he is misguided. 
(Been there.  Done that.)  This can be done only with a Mac (and not a PC) although I do not recommend it.  The DACs should have the facility to synch their clocks. He should consider the exaSound and Okto 8 channel DACs. I am currently using a Merging Hapi II which technically outstanding and can support even more channels.
It is easily accomplished with a multichannel DAC.

Thanks Kal

I kept trying to steer him to the latest eXaSound multi-channel DAC, but he has his heart set on 3x $20K+ DACs instead.
If what you are saying can only be done on a Mac, I think it might be done on Ubuntu too - we make headless servers now that run Ubuntu and can run MC or Roon.

I'm going to reply to eve now and will say what I think I should recommend.
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fitbrit

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #4 on: December 06, 2023, 04:16:30 pm »

USB D/A wont work here.

If he's dead set on multiple stereo D/A units, he'll need to split out AES signals to go to each D/A unit and sync the clocks.
This would be accomplished with an audio interface with the required number of digital outs + word clock out (or slaved to another clock). The audio interface then appears as a single device on the source PC. The audio interface itself could be USB but this way you're not trying to sync up multiple asynchronous USB D/A units.
Additionally, if his desired # of channels is 8 or under, the Okto would be something to look at. Performance / measurement wise it's really top tier.

I think I am going to recommend using a fibre-optic HDMI cable to an 8 channel (4x AES-EBU) VanityPro (link below). And from there, connect to four CH Precision DACs. One of these DACs will be the clock master and the Vanity Pro will be the Slave device. Thanks for your input.

https://www.audiopraise.com/projects/internal/vanitypro/
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eve

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #5 on: December 06, 2023, 04:48:04 pm »

I think I am going to recommend using a fibre-optic HDMI cable to an 8 channel (4x AES-EBU) VanityPro (link below). And from there, connect to four CH Precision DACs. One of these DACs will be the clock master and the Vanity Pro will be the Slave device. Thanks for your input.

https://www.audiopraise.com/projects/internal/vanitypro/
Great solution! I can't see why that wouldn't work, and it'll give him some flexibility re: non PC sources.
The only thing I would say is HDMI doesn't exactly have error recovery / re-transmission so there's hypothetically a slight issue compared to an audio interface with a an async USB driver (that does support retransmission, rare but they do exist. I know ExaSound claims to have actual re-transmission with their ASIO driver).
This is all incredibly, incredibly, doesn't really matter sort of stuff however and for most users, having HDMI will be a huge plus.


Dumb question, what's his plan for volume control / attenuation here? That's a darn can of worms. I would assume if he's going with the multiple D/A units, he's wild enough to want to avoid digital volume control entirely? Although I can give you a paper which posits in almost all scenarios, well implemented on DAC digital attenuation is arguably BETTER than the analog equivalent (mind blowing but the science is pretty sound). Dangerous Music makes a monitor controller that guys I know really like.
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dtc

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #6 on: December 06, 2023, 05:28:09 pm »

Not sure I understand all the issues here, but if I understand correctly you want to send DSD (not PCM) over HDMI. Unfortunately, DSD over HDMI is not supported from a PC. It works from SACD players but not from PCs.
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eve

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #7 on: December 06, 2023, 05:41:51 pm »

Not sure I understand all the issues here, but if I understand correctly you want to send DSD (not PCM) over HDMI. Unfortunately, DSD over HDMI is not supported from a PC. It works from SACD players but not from PCs.

The answer for high end multichannel DSD (especially above 8ch) is the Merging stuff. They've been in the DSD space forever (they make Pyramix) and their extensions of the AES67 standard allow DSD over IP.

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dtc

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #8 on: December 06, 2023, 06:11:24 pm »

The answer for high end multichannel DSD (especially above 8ch) is the Merging stuff. They've been in the DSD space forever (they make Pyramix) and their extensions of the AES67 standard allow DSD over IP.

I am a big fan of Merging. My comment was aimed at the proposed VanityPro solution.
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kr4

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #9 on: December 06, 2023, 06:40:46 pm »

I kept trying to steer him to the latest eXaSound multi-channel DAC, but he has his heart set on 3x $20K+ DACs instead.
If what you are saying can only be done on a Mac, I think it might be done on Ubuntu too - we make headless servers now that run Ubuntu and can run MC or Roon.
There are also software solutions to the problem of getting a PC to control multiple audio devices all of which create a "virtual output device" from more than one individual  device.  However, this flies in the face of logic as there are purpose-designed products from the Okto to the Hapi that will do the job perfectly.  In fact, there is a substantial likelihood that the complexity involved in such an approach can lead to inferior performance despite the vaunted superiority of the individual $20K+ DACs.
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Kal Rubinson
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fitbrit

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #10 on: December 06, 2023, 11:54:55 pm »

There are also software solutions to the problem of getting a PC to control multiple audio devices all of which create a "virtual output device" from more than one individual device.  However, this flies in the face of logic as there are purpose-designed products from the Okto to the Hapi that will do the job perfectly.  In fact, there is a substantial likelihood that the complexity involved in such an approach can lead to inferior performance despite the vaunted superiority of the individual $20K+ DACs.

Your last point is EXACTLY what I said to him, but a person wants what they want. My goal is to give the best advice when my opinion is sought, and then to give them what they want if that opinion is not heeded.
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fitbrit

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #11 on: December 06, 2023, 11:56:30 pm »

Not sure I understand all the issues here, but if I understand correctly you want to send DSD (not PCM) over HDMI. Unfortunately, DSD over HDMI is not supported from a PC. It works from SACD players but not from PCs.

Yes, I am aware of this. The only way to get native DSD in multichannel is via USB, but alas the customer seems to be set on not getting a dedicated multi-channel DAC.
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eve

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #12 on: December 07, 2023, 12:29:57 am »

Yes, I am aware of this. The only way to get native DSD in multichannel is via USB, but alas the customer seems to be set on not getting a dedicated multi-channel DAC.
Merging's stuff will do it, and without USB.
https://www.merging.com/products/interfaces/hapi
https://www.merging.com/products/interfaces/horus

They used to have the NaDAC line for consumers but they've dropped it (technically it lives on under another company).
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fitbrit

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #13 on: December 07, 2023, 12:51:15 am »

I have experience with the Merging NaDAC. Wasn't that impressed at the time compared to the T+A DAC 8 DSD, Denafrips Terminator, and even the lowly iFi iDSD Diablo for two channel sound.
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eve

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #14 on: December 07, 2023, 10:39:11 am »

I have experience with the Merging NaDAC. Wasn't that impressed at the time compared to the T+A DAC 8 DSD, Denafrips Terminator, and even the lowly iFi iDSD Diablo for two channel sound.

That doesn't surprise me too much (glad to know someone actually tried one). It was a weirdly overpriced product IMO. What I noticed was that consumers who 'knew' what it was, were curious enough, to I guess, go the step further and settle into Merging's professional line (which is cheaper, when all is said and done). I don't spend a ton of time in the consumer audio space frankly.
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fitbrit

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #15 on: December 08, 2023, 04:23:58 pm »

There are also software solutions to the problem of getting a PC to control multiple audio devices all of which create a "virtual output device" from more than one individual  device.  However, this flies in the face of logic as there are purpose-designed products from the Okto to the Hapi that will do the job perfectly.  In fact, there is a substantial likelihood that the complexity involved in such an approach can lead to inferior performance despite the vaunted superiority of the individual $20K+ DACs.

What did you think about the Arvus H2-4D? My searching on the web leads me to believe you've tried it  :)
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kr4

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #16 on: December 08, 2023, 05:21:36 pm »

What did you think about the Arvus H2-4D? My searching on the web leads m to believe you've tried it  :)
https://www.stereophile.com/content/arvus-h2-4d-multichannel-dolby-atmos-digital-processor
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Kal Rubinson
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AGAWA

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Re: Multiple identical USB DACs - possible in multichannel setup?
« Reply #17 on: December 10, 2023, 01:43:04 am »

Apogee Symphony Desktop; can be configured up to 6 channels. PCM only. I use it for my Quad setup; 10 IN x 14 OUT simultaneous channels of audio, MAC and Windows. Incredible sound for the money. Replaced my Sony SACD 9000ES player that I thought was hard to beat in terms of MCH and 2ch sound.
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