MQA, where is decoding done, what is required?

[Jimbob54]

My head is starting to hurt!!!

Shopping list to make further enquiries:
1. MQA full decoder DAC (don't have one)
2. CCA (don't have one, but have used one on loan for a short while)
3. Active Tidal subscription (used to have one)
4. Access to non-Tidal MQA files (haven't had, or desired to have, one)

Unfortunately I've used up my Christmas present spending excuse (a Roon subscription and a NUC to set up as a Roon Core). As I don't actually need any thing on the above shopping list, I shall have to continue in my speculation and ignorance.

I have the first 3! Last one so rare as to be a none issue I would say. Unless you're Japanese or easy access to that market.

I will tell you for nothing, just using tidal app to cast to CCA, into a full decoding dac will get you "hifi" quality (aka not mqa). In the roon example, it allows roon either to do first unfold or pass through to full decode. Both roon and smsl (m500} have paid the mqa "tax".

 

[Beershaun]

My head is starting to hurt!!!

Shopping list to make further enquiries:
1. MQA full decoder DAC (don't have one)
2. CCA (don't have one, but have used one on loan for a short while)
3. Active Tidal subscription (used to have one)
4. Access to non-Tidal MQA files (haven't had, or desired to have, one)

Unfortunately I've used up my Christmas present spending excuse (a Roon subscription and a NUC to set up as a Roon Core). As I don't actually need any thing on the above shopping list, I shall have to continue in my speculation and ignorance.

I honestly wouldn't spend money to try and figure it out. Tidal can choose to do one thing and change their mind later or change their underlying distribution technology if they think it's a better solution for their customers.

My suggestion is, if you want to stick with Tidal, is to "let go" and be okay with not being able to control what they are sending you.

 

[Jimbob54]

No, I don't I'm afraid. It's doing what I expected it to do as we know CCA won't deal with mqa. The question, and I think you're getting at the same thing, is do the tidal servers hold 2 copies, regardless of what the apps /website show (master only) OR, in this scenario, is my device getting the same "master" file but it plays it as a standard FLAC 16/44 file BUT that file is less bits of real content because of the mqa guff occupying however many.

The latter is what Bob Stuart suggests should happen. But as if by magic, even that is somehow better than the redbook version.

 

[Beershaun]

I hope this is the case.

FWIW, I asked Tidal support what was happening in this respect.

What a waste of time!

I found their answers either vague or evasive. I came to the conclusion they didn’t want to tell me or, worse, didnt know, and gave up.

Sure. They likely don't know what is actually happening and even if they did it will likely change over time as they evolve their streaming technology, the app capabilities, and the files themselves. Also it's proprietary so they are not likely to share it publicly.

 

[Ron Texas]

I never understood the benefit of MQA. How can encoding information over 24khz and restoring it later produce a more musically satisfying experience than playing back 48/24?

As an aside, do we really need Redbook anymore? Why not standardize music at 48khz just like video?

 

[danadam]

It's about that our hearing is capable to work in a time resolution of 7 milliseconds

microseconds

only 192 kHz has a time resolution of 5,2 milliseconds so is the only resolution who comes close an even beyond the human hearing regarding time resolution.

Time resolution of 44.1kHz is in the order of picoseconds, so 1'000'000 times more than required.

192khz or MQA would be the file to have?.

Even if 192kHz was required, you realize that in MQA anything above 96kHz is just upsampling?

 

[Sukie]

I honestly wouldn't spend money to try and figure it out. Tidal can choose to do one thing and change their mind later or change their underlying distribution technology if they think it's a better solution for their customers.

My suggestion is, if you want to stick with Tidal, is to "let go" and be okay with not being able to control what they are sending you.

I think I can avoid the temptation to spend. I'm more than happy with my current set up (for now)!

 

[danadam]

4. Access to non-Tidal MQA files (haven't had, or desired to have, one)

Free samples, if you needed in the future: http://www.2l.no/hires/

 

[Jimbob54]

I think I can avoid the temptation to spend. I'm more than happy with my current set up (for now)!

As many times as I thought "shit, this sounds good" and looked to find it was mqa, I thought the same and looked to see it was "standard". I have no desire to try and blind test mqa to non, if there's a difference, so be it. As @Beershaun says, take what comes down the pipe and enjoy.

 

[Beershaun]

The latter is what Bob Stuart suggests should happen. But as if by magic, even that is somehow better than the redbook version.

Yeah I am curious to understand if an MQA file itself is truly backward compatible and can be sent to a DAC that only knows and decodes FLAC. I'll see if I can buy an MQA file and test to see if I can stream it to my CCA via PLEX which explicitly doesn't know about MQA.

if it is truly backward compatible then I can see why Tidal would want to go full MQA for everything. It makes their life MUCH simpler to just send one file no matter what the device is and the file figures it out. Also it' supposed to be a smaller size file so it's better for customers who are paying for data as well as reduces their data costs. Win-Win for them.

 

[danadam]

I'll see if I can buy an MQA file and test ...

No need to buy anything, there are free samples available: http://www.2l.no/hires/

 

[Beershaun]

No need to buy anything, there are free samples available: http://www.2l.no/hires/

Thanks!

 

[Jimbob54]

No need to buy anything, there are free samples available: http://www.2l.no/hires/

Rather annoyingly, bubble upnp on android would happily give me file quality info on tidal mqa, but on those free sample mqa files, simply reports it as "FLAC". but both variants of mqa do play back

Edit, when cast through to my dac through CCA, both files report 44.1. No bit depth reported

 

[Beershaun]

No need to buy anything, there are free samples available: http://www.2l.no/hires/

I downloaded an MQA file and was able to play it directly with PLEX on my mac and stream it to my phone from my PLEX server to the bubbleupnp renderer. The metadata showed a FLAC file 44.1khz sample rate but no bit depth information. So MQA is backward compatible as 44.1khz FLAC file.

edit: I was able to see the bitdepth for the file in the PLEX player on my Mac. It shows 24bit.

So it looks like these MQA files are backward compatible and these specific files as 24/44.1khz FLAC files.

 

[Jimbob54]

I downloaded an MQA file and was able to play it directly with PLEX on my mac and stream it to my phone from my PLEX server to the bubbleupnp renderer. The metadata showed a FLAC file 44.1khz sample rate but no bit depth information. So MQA is backward compatible as 44.1khz FLAC file.

Wonder if that would be the case even if the base mqa file was 48khz (as most seem to be)

 

[earlevel]

It's about that our hearing is capable to work in a time resolution of 7 milliseconds (see part one minute 11,30) only 192 kHz has a time resolution of 5,2 milliseconds so is the only resolution who comes close an even beyond the human hearing regarding time resolution. So i guess his argument is that because 192 kHz is capable to project the correct time resolution what we are capable of to hear 192khz or MQA would be the file to have?.

You mean microseconds, of course, but dam—that's an argument for high sample rates (for some people)? The time between samples versus evidence of keen temporal resolution?

I'd like to know the details, but he mentions a conductor, which implies timing of musical events. To be clear, musical events are not limited in any way to the timing of samples. Samples encode not just frequency but phase. There is absolutely no problem with a triangle hit, piano note, or pizzicato pluck coming in a quarter of a sample earlier or later. Or a ten-thousandth of a sample.

I don't want to derail the intentions of the OP, so I won't go on, except to say...sample rate determines the upper bound on frequencies. There is absolutely no time limitation, which is to say, the phases of those frequency components. None.

 

[abdo123]

Can you share what your airplay device is, what your streaming endpoint is that you are playing music from? When you send via Airplay I believe that means you are doing the first "unfold" on the host device (Like an iphone) then Apple is sending the stream from the host device to your renderer via Airplay. So the Server sees your iphone as the endpoint, not your end device. Where as Android Chromecast is using a different method where the stream from the server goes directly to the streaming endpoint and not to the Android phone. So the server sees the Chromecast as the device and not the android phone with the Tidal app.

Wait hold up. So CCA is like Spotify connect but for EVERYTHING? I honestly thought it is Google’s equivalent for Airplay.

 

[Roland68]

Unfortunately, I still can't tell at which point MQA is decoded in a DAC if the DAC chip does not contain an MQA branch.

As an an example:
With a topping D90 MQA, there should be a chip in front of the AK4499, in which the MQA decoding takes place.
1. Does the topping D90 fully unfold MQA? Or only partially?
2. Is this chip a special IC from MQA, or simply a processor with software from MQA?

I also own a Pioneer XDP-30R which supposedly can "MQA".
This MQA function was subsequently added through a firmware update.
Unfortunately, I can't find any information about whether this MGA function is fully developed or only halfway.

How do I know how far the MQA function / implementation goes with a device?

 

[abdo123]

I would really not buy a CCA for Tidal no matter how convenient it may be.

I would do Roon or DLNA (with a raspberry pi).

 

[Jimbob54]

Wait hold up. So CCA is like Spotify connect but for EVERYTHING? I honestly thought it is Google’s equivalent for Airplay.

Kind of. A mix of both. The receiving device needs to be "cast" certified. And something (phone etc) needs an app (or cast enabled browser on a PC) that can do the controlling.