MQA signal path not showing correctly in Roon

Hi,
I just installed RoPieee on my Raspberry Pi 4B and connected my Meridian Explorer². It immediately showed up in Roon and I enabled it as audio device. When I first played a MQA song from Tidal Roon showed the “blue light” as well as the Meridian Explorer² (the DAC has a few LEDs and one of them lights up in blue if the DAC plays back MQA). After a reboot of the Raspberry Pi Roon does not show the “blue light” anymore but the Meridian does.
The Meridian’s device settings are set to:

  • MQA-Capabilities: Decoder and Renderer
  • Enable MQA-Core-Decoder: No (I also tried setting this to yes but it didn’t change anything in Roon but the light on the Meridian is still blue)

I also tired all the USB ports on the Raspberry Pi but that unfortunately also didn’t change anything.
Using the Meridian Explorer² as a renderer only and using the Roon Server to do the first unfold does not work, because of some bug in the Explorer².

This is a picture of the signal path Roon shows:

As I’m pretty sure that MQA is working correctly because the light is blue on the Explorer², it has to have something to do with Roon. I really don’t know why the signal path is not displayed correctly so I’d appreciate any help. Thanks in advance :slight_smile:

To me, there is nothing wrong with this signal path. In Roon the coloured star changes when applying dsp to the signal, from lossless to enhanced.

Is you want to apply dsp to you MQA signal, this should be set to yes. Only then, the DAC will render the file as MQA.

Thank you for your reply @Arlen.
The signal path to my Bluesound Node 2i playing an MQA song looks like this:

This is the “blue light” I was talking about earlier. Without MQA the “light” is more like purple.

I also didn’t apply any DSP. I know that for other DACs it’s possible to let Roon do the first MQA unfold and then let the DAC only render the MQA. But unfortunately this is not possible with the Meridian Explorer² because of some hardware bug as far as I know. This is what the setting “Enable MQA-Core-Decoder” is for, but it doesn’t affect the Explorer².

I’m colourblind, so I cannot see the difference between these two colours. The decoding step in your second signal path might be because this DAC accepts RAAT and can communicate what it is doing to the core.
The Meridian device doesn’t do RAAT.
If your Explorer shows the MQA light, then I assume it will render it correctly.

What happens when you connect the Explorer to your core directly, via usb?

This is a very good question but also a good idea :smiley:
Unfortunately I cannot try that out today anymore cause my Roon server runs on docker and I’ll have to figure out the USB passthrough. Tomorrow I’ll try to connect the DAC directly to the Core and post the results here.

The “lights” in Roon’s signal path have nothing to do with MQA or the lights that show up on a DAC when MQA is played. The color coding that Roon uses is Roon’s way of showing you the quality at each step (blue for enhanced, purple for lossless, green for high quality, etc.).

What I do find odd about your signal path in your first post is that it doesn’t show MQA full decoder. Are you sure your Meridian Explorer supports decoding and rendering and not just rendering? You might want to try enabling Roon’s core decoder and setting capabilities to render only and see what happens.

Of course, that’s correct. Sorry for using a misleading description. I was just referring to the “enhanced” signal path when playing a MQA file which results in the “blue light” in Roon. And coincidentally the Explorer² also has a blue light when playing back MQA :smiley:

As I tried to explain earlier, using Roon’s Core decoder and the Explorer² as renderer does not work. I tried this multiple times but it doesn’t work due to a firmware limitation of the Explorer². I even found a forum post about this issue (https://community.roonlabs.com/t/meridian-explorer-2-mqa-renderer-only/62597/5?u=luca_quaer).

I’d say that’s more than a limitation. That’s just a bad implementation.

@glc650 Well, unfortunately I cannot do anything about that but accept it. I also checked for a newer firmware version but it seems like Meridian completely dropped support for the Explorer² (I couldn’t find any downloads from official sources anymore). The latest firmware version I found was v1717 and that’s the version I have installed.

I couldn’t figure out a way to easily get USB passthrough working to my Roon server but I tried connecting the Explorer² to a Computer running the Roon program.
In this case the signal path looks like this and the Explorer² confirms that MQA is working with its blue light:

The device settings of the Explorer² were automatically set to

  • MQA capabilities: Decoder and renderer
  • Enable MQA core decoder: Yes
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Bluesound is Roon Ready and therefore can report back all steps for the devices signal path and what it is doing hence why you see the MQA step after the RAAT part. Roon bridge via USB does not always have full reporting and may be a limitation on Linux? I did have hit and miss with it showing the MQA decoding side myself when I used Roopiee to my SMSL DAC as a full decoder and renderer. I do think this side of Roons code is a bit flakey as a reboot can often restore it back.

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I just reinstalled RoPieee XL on my Raspberry Pi, restarted my Roon Server and checked if using a ethernet cable instead of WiFi made a difference. Everything stayed the same.

Thank you for your reply @Simon_Arnold3. As you describe it, it’s not unusual to sometimes see the correct signal path which coincides with my experience when I first installed RoPieee. But as I couldn’t restore it by restarting the Core and reinstalling RoPieee (and also the Roon Bridge on RoPieee) I probably just have to give in and accept it. At least the Explorer² shows that MQA is working properly and because of your comment I know, that the signal path visualization issue is probably due to some bug in Roon.

Thank you all very much for helping me out :slight_smile:

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RoPieee and Zen Stream are both Linux and reported correctly when used with a Topping D90SE. Also worked when I used a Zen Stream with Sabaj A20d 2022. I think the OP’s case is just a bad product with poor MQA implementation (his DAC even fails to render MQA if Roon is doing the core decoding).

I’m not sure that’s on Roon with the way MQA is implemented on your DAC. Have you asked Roon? Curious what they would say.

Are they not active in this forum? Or do you think I should ask via email?

I think you have to post in the support section to make an inquiry official with them.

Meridian were the first to add MQA to any DAC and obviously have ties to MQA due to Bob Stuart so I would find it odd if it’s the implementation but stranger things have happened.

I hear you but the OP already mentioned not being able to use Roon’s core decoder. I don’t think I’ve seen another instance on this site where an MQA DAC capable of decoding and rendering didn’t work with Roon doing the core decoding. And this is MQA we are talking about after all. It’s hardly the poster child for great, well executed products.