NAD C658 with Roon's MQA Core Decoder

Core Machine (Operating system/System info/Roon build number)

Roon Version 1.7 (build 710) stable (64bit)

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

NAD C 658

Description Of Issue

When Roon’s MQA Core Decoder is being used to apply DSP, the MQA logo is no longer visible on the C658. Can Roon please confirm if the second MQA unfold is being done properly or not and maybe have this fixed? Thank you.

Screenshot 2020-12-28 075837

Take the headroom adjustment out to get pure mqa.

The headroom adjustment is just there to present what happens when Roon’s MQA Core Decoder is being used (otherwise it would just passthrough the MQA file). This happens with any kind of DSP in Roon. The issue here is about the NAD C658 with MQA and DSP.

Roon signal path is telling me that the final unfold is being done, yet the MQA logo does not appear on the C658 in this mode. One of the two is not telling the truth. So, shouldn’t this be fixed?

Ged, I knew that already. But that still doesn’t answer the question or fix the issue. The device is Roon Ready, so I’m assuming that this should be fixed.

Another DAC I own, the Audioquest Dragonfly Cobalt, has no issue rendering MQA with Roon’s DSP (except when using Audeze’s Linear filter, which is another issue: Bith Depth Restore with MQA Signaling not working with Audeze Linear filter)

Odd that its not working and showing as correct in your signal path. I have used DSP fine in the past for MQA into a DFC and my SMSL SU 9 I take it you have the MQA capabilities in Roon set as renderer only for the C658? Can’t see in your screen grabs. When I have had issues in the past with MQA when I had the Dragonfly Cobalt a reboot of the core seemed to fix it. Sometimes it didnt shoe the orfs renderer stage at all until this was done. Especially if I was unplugging the DAC from the endpoint.

The NAD C658 is set as Decoder and Renderer, as it should be. Setting it to Renderer Only doesn’t change the behavior for this situation. The same goes for rebooting. This issue has always been here, but the C658 is Roon Ready now, so I’m assuming it’s actually supposed to work.

I’m assuming you are also asking NAD, since if the issue is their display only they can fix it, not Roon.

Hi @Arash,

Thanks for reaching out! I’m going to inquire with our hardware team on this one, it may take a bit to hear back due to the holidays so your patience here is appreciated! You may also want to reach out to NAD in the meantime as well.

Thanks @noris,

NAD has been notified as well.

Happy holidays :slight_smile:

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@Arash Is there any update to this?

Nope. Hope Roon addresses this together with NAD soon.

I wonder if this is the C658 in particular or of other BluOS devices eg M10 are affected. I’m just considering some of the NAD offerings right now.

They all use the same BluOS software, but that doesn’t confirm or deny whether other NAD products share the same issue (I only have the C658).

It seems like it’s a bug though, since the C658 has no issue with the ORFS step in MQA rendering when applying Dirac to the stream. Roon properly shows the ORFS step in the Signal Path and the C658 shows the MQA logo as expected. If it’s possible with Dirac, I don’t see why it would be impossible with Roon’s DSP.

Following on here since I have the same issue with my N10.

@noris Any news on this issue here?

Hello @RBO ,

We’re working with NAD on this issue, for the latest updates please reach out to NAD, thanks!

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Thanks @noris

Hopefully it gets resolved. It seems it has been a known issue for some time and BluOS (whose software runs on the NAD M10 and other NAD Roon Ready products) say it has nothing to do with them and ask us to revert back to Roon.

“Your concerns are with the ROON Software - I would contact them. That being said, I am guessing as soon as you enable any sort of change to the DSP, you are violating MQA process so are no longer hearing MQA because you are altering the audio content.”

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Happy to see this issue has now been sorted with the latest BluOS update today. MQA now displayed on NAD M10 screen with Roon DSP applied.

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