What is the difference between MQA on Roon vs MQA on a DAC?

New to MQA and would like to understand the difference between MQA on Roon vs MQA on a DAC, like Bluesound Node 2 or Mytek, etc. Does using Roon 1.5 with this MQA capability negate the need to purchase an MQA capable DAC to hear the benefits, let’s say from Tidal MASTERS?

I guess you could say that it’s performing the most important part, ie MQA decoding. With a downstream non-MQA DAC you would not be getting the ‘rendering’ part, though many such DACs might still upsample to quite good effect.

Referring to

Roon MQA with a non-MQA DAC is case B.
If you use a MQA full decoder DAC, it (usually) is case D.

There’s no need to purchase a MQA DAC as all the information is decoded by Roon in the first unfold. The ‘renderer’ part found in MQA DAC basically perform up-sampling and final ‘de-blurring’ filters, not actual retrieval of information. Another advantage is it allows DSP+Room correction to be done in the software.

Thanks. So if there is a first unfold, you’re saying that in this case, there is only one and the original file resolution is fully restored and then rendered completely in software by Roon.

No, Roon does not Render. It’s first unfold only. You would need an MQA ‘rendering capable’ DAC to complete the whole process (and not all MQA DACs will render unless they are allowed to do the decoding too). So, you live with just the main unfold from Roon, or get a DAC that does full decoding/rendering, or one of the ones which will do the rendering stage after Roon does the unfold.

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That is correct.

Did the Mytek Brooklyn render after the unfold is done by Roon?

yes it seems to be doing that based on the magenta mqa indicator on my brooklyn.

i love that this seems to also be with volume leveling and convolution in place.

i have not yet had a chance to listen to the audio quality since i’ve only had a few minutes with it in between my hectic schedule

As far as retrieval of information is concerned, first unfold is actually doing the ‘de-compression’ or simply unzipping a file.

The original file (PCM masters) is NEVER restored to bit perfect when it is encoded by MQA. That’s why MQA is considered lossy in nature. The renderer part is just ‘up-sampling’ with the selection of ‘de-blurring’ filter to match the DAC chipset; it is more like doing ‘conditioning’ to match the DAC characteristics.

Are DAC specs quite clear on what they will and won’t do? I was considering a meridian prime headphone amp but now I’m not so sure it will work well with Roon. Meridian may update the software…but they may not if a hardware revision is needed.

Search and ask in this forum. For the particular limitation of some certified MQA decoders not properly handling unfolded MQA Core signal from Roon, it usually requires a firmware update only, not a hardware revision.

If I have a full MQA decoder and renderer, does Roon have the option to NOT make the first unfold?

Yes, select MQA decoder and renderer in the device setup, Roon will automatically detect if you have a full MQA decoder/renderer. Another option is to disable the MQA decoder.

Thanks for that info. I don’t however understand why I would disable the MQA decoder? If its a good quality one, I would think that the synergy of having the complete 3 unfolds/renerer by the same manufacturer would be the way to go. I have Mytek Manhattan II and it sounds magnificent–Redbook<Hi Rez downloads<MQA 24/96<MQA 24/192<MQA 24/352 (The best). I am thinking of Roon for the Nucleus/storage and less the organization of may collection, which is currently
only a few hundred ripped cd’s and a few dozen Hi Rez downloads. Expect it to get much bigger. However, if I can get over the idea of not having the physical media, its a lot less expensive to have a large collection. I am thinking that I can download and save MQA files from Tidal with Roon. Am I correct?

Disabling MQA core decoder means Roon will pass bit perfect MQA information to your Mytek MQA decoder/renderer DAC to do all the processing.

Actually there’s only one unfolding and the other is rendering. Unfolding occurred at the MQA core giving a max of 88.2/96k, that’s where all the musical details are retrieved. The renderer will then take 88.2/96k and ‘up-sampled’ with selected MQA filters to the maximum capability of the DAC chip. Most DAC chips will max out around 352.8/384k, the higher end may go as high as 768kHz.

What you are seeing on your display of all MQA DAC is not actually sampling frequency that goes to the internal DAC chip but rather the ‘authenticated’ sampling frequency, similar to Roon display on the signal path. These are ‘flag’ telling this track is mastered from a original source sample and nothing more.

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Nope, cannot do that.

In terms of the original question, there is another super long thread discussing the same issue so you might find that and see what the opinions are. Some say that MQA really doesn’t shine until it goes the full path all the way to the last unfold/rendering. That requires hardware only in an MQA DAC.

Thanks for letting me know that I cannot download Tidal MQA Streams. I was surprised when I saw that, but perhaps TIDAL lets you download for a cost. I have been using HD Tracks and ProStudioMasters for all my HiRez downloads so far.

I cannot comment on the need to do the full mqa decode for it to shine. I can say that when I do via my Mytek Manhattan II, the results are spectacular. I have no need to do the first unfold in Roon, but might find it helpful to organize my downloads, and Naim Unity Core. Since I got the MM II 10 days ago, its been all Tidal Masters. I have not found a bad one. When I compare to either Redbook or to Hi Rez, its always better in MQA–but that is my system. YMMV.

Hi Gary - in reflection, I’m not sure my answer is entirely correct, or at least full. What I do know is that you cannot download MQA streams from Tidal and just move them around in explorer and play them through any software (and that would include Roon I think).

Tidal does have a download function but it acts more as a cache for the Tidal app - i.e. you can download for offline playback ONLY through the Tidal app, if I understand it correctly.

I don’t know if that includes MQA streams. My answer was based on the idea that you cannot just add Tidal a track to your local collection and have it there, exposed, like a FLAC file. But there is a way to “download” tracks for off-line secure playback through the Tidal App.

Just to give a bit more detail on whats going on. The way MQA works is it downsamples whatever it is fed to at the most 96k sampled audio (sometimes 88.2 or even just 44.1k). If 96k, it uses a trick of breaking it into two bands 0-24k and 24-48k - remember the highest frequency that can be transmitted is half the sampling rate - so each band is sampled at 48k. It then losslessly compresses the 24-48k information and puts it in the lower bits of the 0-24k data. This of course adds noise to the 0-24 bit data, but it acts like whats called dithering so the extra noise is not that noticeable - you can look up dithering for how it works. Instead of 24 bits depth it is effectively about 20 bits which is still below the noise floor of most recordings. This is called stacking by MQA or sometimes the first fold and is reconstructed losslessly except for that bit of added noise that is nearly always below the noise floor of the recording anyway. This is what Roon decodes. Now in the second unfold they try to guess at the information lost in the down-sampling - thats the part only a MQA DAC does. We have a down-sampling and up-sampling filter pair. What MQA does is analyse the recording to determine the best filter pair to use so what the MQA people consider important - time smear - is reduced. They also use watermarking techniques to tell the dac what upsampling filter is best to use from the many the DAC knows about. But here is an interesting point - only a very very small number of recordings - I seem to recall less than 1 in 10000 - have any content above 48k - it’s nearly all noise. So in reality the first unfold is all you really need anyway. The DAC you feed it into will usually do its own up-sampling - but not the optimum one determined by MQA. Thats the only difference really between a MQA DAC and normal DAC. Is it audible? From my experience sometimes it is - but the question that is important is does it sound better. Not everyone agrees on that. So IMHO choose the DAC, MQA or non MQA, that sounds best to you. Personally I use a Direct Stream non MQA DAC (you can get a MQA version, but am looking to move to a Chord and a M-Scaler). MQA DAC’s fed with MQA often sounds a bit (and I do mean bit) different - but I cant say which is better.

Thanks
Bill

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