DSD over RAAT vs USB

Roon Software Discussion
1

The more i delve into this, the more confused i become! :slight_smile:
Hear me out, please;
I have several Ethernet2USB bridges talking RAAT to my Roon Core, i also have a couple of USB DAC’s that do DSD128 or more. All of these works just fine, but none of them seem to allow for more than DSD128 in Roon?
I generally don’t do Windows Roon Bridge but i made an exception and installed the drivers (ASIO) for the DAC module in my Moon Nëo 430HAD, connected it to the Windows lappy with an USB cable, and voilá: DSD256, Native!
I have tried all kinds of settings in the SOtM sMS-200, the USBridge, The Aries (G1) and on various Mac’s and SBC’s but it seems it takes a Windows can to crack this?

Can somebody explain why this is so and if anything can be done about it? (It’s not really a necessity, just curious!)

2

You can load the necessary driver for Windows. Manufacturer’s don’t make MAC or Linux drivers usually.

Some Linux based Ethernet to USB endpoints have been patched on a DAC by DAC basis to allow for native DSD. Investigation is needed to see if your endpoint has been updated for your specific DAC. For example, you would need to investigate to see if the microRendu works for that model Moon by reviewing their list of native DSD compatible DACs.

3

Am i understanding you correctly here?:

  1. Driverless operation in either Win10, Mac or Linux limits DSD bitrates to DoP DSD128
  2. With a native driver on the USB host you may accomplish DSD256 (DoP or Native) or higher?

I seem to recall PCM768 and DSD256 without drivers on my old Chord Mojo, but i dont have it anymore.

4

And, as a lot of things in life, it depends. And there may be other hardware limitations as well.

Lets talk about MAC first. Doing Native DSD requires ASIO drivers. Most manufacturers do not make MAC ASIO drivers to do Native DSD. Exasound is one of a few that do, however. So, playing back to a MAC is done via DoP which encapsulates the DSD in a PCM wrapper. To do this, extra bandwidth is taken up for the wrapping, so if your DAC was 384PCM / 256 DSD it could only do DoP 128. If your DAC was 768 PCM then it could do DoP 256, for example, and as you were kind of remembering from the Chord.

Linux is in a similar boat. Except, that some endpoints manufacturer’s have patched drivers into their product’s code to provide native DSD. However, the implementation is on a DAC by DAC basis and on a product by product basis. So, while a microRendu might be able to play native DSD for a specific DAC, it does not mean that other Linux based products can. That is why you need to verify with the manufacturer of the endpoint which DACs have been patched in their product to allow native DSD. IMHO, it is a bit of a wild west situation that is slowly getting better. Some DAC manufacturers like T&A DSD DAC 8 have just come out and said Linux wont work. Some patches are for USB implementations like XMOS rather than for a specific DAC. You have to do research. I see you have a Moon, I’d shoot them an email asking what they suggest for native DSD playback.

With Windows it is easy, you just load the ASIO drivers provided by the manufacturer and you are golden. I"ve never tried using Windows and not loading the driver; but I suspect it would generate DoP as well.

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5

First of all, thanks for elaborating! :slight_smile:

And regarding your suspicion, it is hereby confirmed, before i loaded the driver the Moon automatically installed itself in Win 10.
However with WASAPI and DSD DoP128

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