Tidal/MQA on non-MQA DAC

My primary streaming source is Tidal, and my existing DACs are all MQA-enabled. My playout chain is via HQPlayer, where I upsample to DSD256 before passing to the DAC. Does that then mean that all MQA decoding is being carried out in software before reaching the DAC, as my understanding is that upsampling would prevent authentication of the MQA chain?

Also, having empirically discovered that MQA encoding makes far less difference on most material than DSD upsampling, if I now move to a non-MQA DAC (Tambaqui), will the same source albums play out, with or without MQA decoding in Roon?

thanks

Hi Richard

MQA does unfolding twice. The first can be done in Roon, as Roon Core MQA decoder. The 2nd must be done in the DAC. If the 2nd unfolding misses, you loose basically frequencies above 88 kHz.

In this case Roon does the first unfold and passes the data to HQPlayer.

If there is still important information above 88 kHz I highly question. I personally would prefer a Tambaqui DAC over MQA.

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You have a choice. Full MQA or HQPlayer. You can always do the first unfold in software, be that Roon or any player that supports MQA. The second unfold happens in the DAC and is specific to that DAC. If you use HQPlayer you will lose that second unfold because HQP will resample to what you tell it, not what MQA indicates is the target resolution.
In my opinion HQP more than compensates for anything you might consider lost by not having that second unfold.

Roon can only do the first decode step. The render step is locked to the DAC hardware (mainly the USB chip since that is where most MQA implementations do the render stage). So, what you are currently doing is having Roon do the decode stage (assuming you have this turned on) and is sending that to HQP. You have been skipping the render stage.

The whole point of Roon doing the first decode step was to allow MQA to be used partially on non-MQA DACs. But, since you’ve been using HQPlayer, having an MQA DAC is doing nothing for you since HQPlayer (or any upsampling or room correction) destroys the MQA control signal.

Actually, it will make no difference to what is currently happening (assuming you are still using Tidal). Roon will still do the decode stage as it is now, and then send that on to HQPlayer.

Thanks for clarifying - it’s not always obvious what is happening where! I agree, BTW - having had several MQA DACs, using HQP/DSD upsampling makes a far bigger difference than moving from MQA-encoded content at 44.1 to straight Red Book. So I’m entirely not bothered about losing that second unfold, as long as I’m effectively getting the full, pre-MQA, source res.

thanks, I tend to think the same.

Assuming the same so I did the Dac firmware upgrade without the mqa so now I have a non-mqa dac.

I feel the same.
I do not have Qobuz available so only tidal. Not so many high Rez local files. So for higher MQA’s from tidal I use the mqa/mp3 filters (when I do not forget):

Screenshot 2023-06-05 at 19.03.18

Well, if upsampling/room correction is done in Roon, you still get the 2nd unfold done in your MQA DAC. Don’t know about HQPlayer

Here’s my signal path

Roon knows how to preserve the mqa before DSP and how to restore the mqa before outputting to dac. This is what I was using before I bought HQP. To my knolage HQP does not do that. But still: using HQP I like the sound better.

I’m not 100% sure there, as my understanding of MQA was that any change to the playout chain that effectively invalidates the expected format at each step, would result in just the initial unfold taking place, and what would be processed in your DAC would be the original source, without any MQA bells & whistles. I can’t immediately see how upsampling wouldn’t break the authentication chain.

If you read Roon’s Knowledgebase here and see excerpt screenshot, you might want to change your mind …

The signal path shows MQA being the source and MQA being played by the DAC and the DAC also shows the MQA badge when playing the music… So somehow Roon seems to do the trick as @Traian_Boldea points out.

I don’t use HQPlayer so I can’t judge on how it works or sounds.

To my ears, 2nd unfolding of MQA does not make a great difference in sound while first does (at least with some albums), so a good non-MQA DAC might sound better than a not so good MQA DAC with Roon

There are certain types of DSP which can be applied by the user which Roon will be able to maintain the MQA control channel. However, if I upsample in Roon the output of the decode stage to 192.24 for example, the MQA information will not be maintained.

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The OP is using HQPlayer in the playback chain. HQPlayer removes any and all MQA control information, so whether or not you maintain the MQA control bits in Roon, it is gone when HQPlayer is done processing.

Yes, I had to go back to my old DAC. To remember

All DSP works and MQA is still there. But the upsampling does not work by default. I have to disable MQA for the dac in order to be able to upsample. (hope the screenshots make sense)

Exactly. When I used Tidal that is exactly what I did. Since I didn’t have a MQA DAC, I had no need to keep the control signal, so I then let Roon upsample the decode stage to whatever output resolution I wanted.

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@Rugby and @Traian_Boldea You are right. Some DSP functionalities work, other don’t with MQA. Convolution filters and headroom work, keeping MQA 2nd unfold at the DAC.

If I select upsampling in my DSP settings, it won’t upsample MQA material: you get the original MQA 2nd unfold bit rate. The upsampling is not applied by Roon to MQA material by default even if you select it in the DSP.

That certainly appears to show MQA metadata being preserved through the signal chain, after DSP processing. Slightly surprised at that, but clearly something that Roon manages well. I’m of course handing off to HQPlayer for the DSP element and my (so far limited) understanding there is that you need use Jussi’s MQA-specific filters to maintain MQA integrity through the full signal path.

Does it? I haven’t found reference to that. Only that it imitates the final 2nd stage render filters. We can of course ask the man himself instead of theorizing. @jussi_laako

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Yes. To do the upsampling you have to set the dac as “no mqa support”

You can use those words but also you can use the words “to use Jussi’s MQA specific filters to compensate for the magic of mqa” I guess depends on your point of view. 2 years ago I was chasing MQA dacs now I do not even install the firmware to enable MQA :slight_smile:

That was merely my working assumption - my DAC’s streamer board has just expired, so haven’t been able to check that.