Native DSD not working with Nucleus One and Musical Fidelity M6x DAC

[Brain-Proxy (Andrea Seifert)]

Roon Server Machine

Roon Nucleus One, Operating System Version 2.1 (build 271) production, Server Software Version 2.50 (build 1528) production

Networking Gear & Setup Details

UniFi Dream Machine, Ethernet

Connected Audio Devices

Musical Fidelity M6x DAC, connected via USB

Number of Tracks in Library

4700 albums

Description of Issue

Hello,

When my Roon Nucleus One is connected to the Musical Fidelity M6x DAC via USB, Roon only presents the DSD over PCM (DoP) option—there is no Native DSD setting. I specifically chose the M6x because it supports native DSD playback. Could this limitation be due to the Roon operating system not recognizing the DAC’s native DSD capability?

Thanks,

Andrea

[DDPS]

Looking at https://www.musicalfidelity.com/uploads/catalogerfiles/m6x-dac/4_M6x_DAC-Issue-1.pdf and looking at page 7 in particular, I can only gather that Native DSD support is only supported when connecting to a Windows machine and running their driver. The Nucleus is a Linux box and likely only supports DoP.

Many playback devices share this idiosyncrasy.

This should not be a problem, since DoP is in fact pure DSD, just transported/encapsulated en route to the DAC in a PCM container. It is still handled as pure DSD once it arrives at the DAC. The only disadvantage is that it requires twice the bandwidth as a Native DSD stream would, and that you can only play up to DSD 256 via this method; DSD 512 files would require that you use a Windows machine with their driver. If you have no DSD 512 files, then you should not have any problem here…

[Brain-Proxy (Andrea Seifert)]

DDPS, thank you for your reply.

I have a sizeable library of DSD512 albums, and that’s when the lack of native DSD playback became an issue. Because the Nucleus can’t play them directly, it automatically downsamples to DSD256. Unfortunately, the Nucleus doesn’t have enough processing power for that on‑the‑fly conversion, so playback stops.

[noris]

Hi @Brain-Proxy ,

@DDPS is correct here, for native DSD, you would need the required drivers and only a handful of devices support native DSD on Linux. When you are trying to play the DoP content, what processing speed does the Signal Path show, is it under 1.2x? If you try to play DSD256 content with no conversion needed, does that work as expected? There is also an option called Parallelize Sigma-Delta modulation in MUSE (DSP) you can try to enable which may help: