MQA is Vaporware

[Fokus]

6 minutes ago, Fx Studio said:

Not according to the manufacturers who use these DAC chips they say there products are an "MQA Full Decoding."

 

'Full Decoding' is obtained by 'Core Decoding' in software (on a PC or else a microprocessor in the DAC box), and then 'Rendering' in the actual DAC chip.

Core Decoding is the decryption and then the first (and only) unfold.

Rendering is upsampling with extremely simple short filters.

 

If I rememember correctly. I have been out of this BS for a long time now. Rest assured that I have forgotten more about MQA than you will ever know, let alone understand.

 

 

 

[Fx Studio]

20 minutes ago, Fokus said:

 

'Full Decoding' is obtained by 'Core Decoding' in software (on a PC or else a microprocessor in the DAC box), and then 'Rendering' in the actual DAC chip.

Core Decoding is the decryption and then the first (and only) unfold.

Rendering is upsampling with extremely simple short filters.

 

If I rememember correctly. I have been out of this BS for a long time now. Rest assured that I have forgotten more about MQA than you will ever know, let alone understand.

 

 

 

 

Nope, that's the first unfold that is done in software - the DAC is needed to do the Full Decode. 

 

 

 

[stefano_mbp]

15 minutes ago, Fokus said:

If I rememember correctly

You don’t…

MQA Full decoding means the ability to perform all three unfolding processes , in this case the player can be configured as MQA passthrough.

A MQA Renderer dac needs instead the first unfolding process done by the player

 

[JoeWhip]

I wouldn’t go on any Russian download site, even with a condom.

[Fx Studio]

27 minutes ago, JoeWhip said:

I wouldn’t go on any Russian download site, even with a condom.

 

Pull on your big boy pants, take another big slurp of that Soy Latte with caramel drizzle, slam down the cup George McFly style, wipe foam from mouth using back of hand => and get in there!!

[John_Atkinson]

3 hours ago, Currawong said:

Time smearing correction is not physically possible.

 

Incorrect. My 2018 article on A/D conversion - https://www.stereophile.com/content/zen-art-ad-conversion -  gave an example of how this was achieved using an A/D converter with a slow-rolloff antialiasing filter (a dCS 904's F4 filter) and a D/A converter with a slow-rolloff reconstruction filter (an Ayre QB9's Listen filter).

 

John Atkinson

Technical Editor, Stereophile

[FredericV]

1 hour ago, Fx Studio said:

Not according to the manufacturers who use these DAC chips they say there products are an "MQA Full Decoding."

Show me the data sheet

[Currawong]

2 hours ago, Fx Studio said:

 

2. OMG you never check anything do you - the whole of the AKM 449x series and the ESS ES906X series of DAC chips.

 

No, the AKM chips don't have MQA decoding on board. The "single one" I was referring to though was indeed the ES906X.

 

1 hour ago, Fx Studio said:

Not according to the manufacturers who use these DAC chips they say there products are an "MQA Full Decoding."

 

The decoding in most devices (the ones excepting those that use the EX906 series) is not done on the DAC chip, or filter chip in the case of the new AKM DACs that require the 4191. It's usually done in another chip, such as the XMOS series that has MQA decoding built in. What is more, if you to AKM.COM there isn't a single mention of MQA anywhere on the entire site.

 

You really seem to have difficulty handling hard evidence, especially after some time back you asked for it, ignored it, and continue to ignore straight-up facts. 

[Fx Studio]

5 minutes ago, Currawong said:

 

No, the AKM chips don't have MQA decoding on board. The "single one" I was referring to though was indeed the ES906X.

 

 

The decoding in most devices (the ones excepting those that use the EX906 series) is not done on the DAC chip, or filter chip in the case of the new AKM DACs that require the 4191. It's usually done in another chip, such as the XMOS series that has MQA decoding built in. What is more, if you to AKM.COM there isn't a single mention of MQA anywhere on the entire site.

 

You really seem to have difficulty handling hard evidence, especially after some time back you asked for it, ignored it, and continue to ignore straight-up facts. 

The exact implementation is proprietary and varies from manufacturer - some use ARM or other microcontrollers before the DAC some do not. But either way the DAC needs the filter settings to be available for setting for MQA. So the DAC needs to be MQA compatible for it to work.

[The Computer Audiophile]

1 minute ago, Fx Studio said:

The exact implementation is proprietary and varies from manufacturer - some use ARM or other microcontrollers before the DAC some do not.

Dude, your speaking in circles and moving goalposts to defend your position. 

[Fokus]

Quote

You don’t…

MQA Full decoding means the ability to perform all three unfolding processes

 

Nope, ...

 

Learn how to read, both of you.

 

And there are no three unfoldings. Only one. Or none.

 

[stefano_mbp]

7 minutes ago, The Computer Audiophile said:

your speaking in circles and moving goalposts to defend your position. 

He read The Art of Being Right for sure … 

[JoeWhip]

37 minutes ago, Fx Studio said:

 

Pull on your big boy pants, take another big slurp of that Soy Latte with caramel drizzle, slam down the cup George McFly style, wipe foam from mouth using back of hand => and get in there!!

Sorry, but I am a tea drinker.

[JoeWhip]

28 minutes ago, The Computer Audiophile said:

Dude, your speaking in circles and moving goalposts to defend your position. 

I think he moved the goalposts over the horizon, where they disappeared from the bottom up.

[Gustave]

From the Lenbrook press release:

 

Quote

George Massenberg, Grammy winning producer and recording engineer, reacts saying “I’m so relieved that MQA and SCL6 will continue under Lenbrook. MQA’s technology, with its faithful rendering of detail, complexity, and sound stage, gave us the reason to go back into the recording studio and reverse a 20-year decline in the quality of audio delivery methods.”

 

By the way, the gentleman who contributed this well-considered and conclusive comment is called Massenburg and not Massenberg.

 

What are we to make of a company that can't even keep the names of its best advocates to the truth?

[Indydan]

That Peter Veth must have orgasmed in his pants, when he heard the announcement that Lenbrook had bought MQA...

[jhwalker]

16 hours ago, John_Atkinson said:

You are welcome, of course, to regard it as "lossy"

 

John Atkinson

Technical Editor, Stereophile

Thank you - I will, because it is.

 

PS - It's not MY "comprehension skills" lacking  🙄

[garrardguy60]

17 hours ago, John_Atkinson said:

 

And as I wrote,  regardless of your statements I didn't say MQA was lossless.

 

John Atkinson

Technical Editor, Stereophile

 

You can be a respected authority or you can be a bullspitter. Most people choose one or the other. You, however, appear to want to be both. At the same time. 

 

 

[Gustave]

To be honest, I love John Atkinson for all he has done to promote audio culture over the past decades. And I've come to his defense here in this thread as well. But this recent hair splitting on the terms Lossless vs Lossy makes me feel like I may have been wrong.

 

Robert Harley, Jim Austin and many others seem to have chosen the dark path when it comes to MQA. It would be a shame if John Atkinson joins them instead of building bridges for the good of all.

[watts]

[KeenObserver]

Stereophile and TAS must have fallen upon hard times such that come to AS posting the same old MQA BS looking for clicks.

Very sad.

[KeenObserver]

11 hours ago, ARQuint said:

 

Now that's  ironic, Arch.

 

Thanks to a small number of loyal warriors, the Vaporware thread remains robust despite the fact that MQA is dead and gone. Reminds me a little of the Japanese soldier who continued to hide out in the Philippine jungle, engaging in guerrilla actions for 29 years until his former commander traveled from Japan to relieve him of duty. Chris, could you please award KO a medal for his service so he can move on? Poor guy—all his AS posts still relate to MQA. Wait until he has the time to discover the various other non-MQA aspects of this hobby that people enjoy. Like listening to music.

 

Andy

 

Your fixation on my posts seem to be excessive.

See a Doctor.

[Jud]

13 hours ago, Fx Studio said:

But you guys have already decided how its going to be, and won't accept any other information

 

This is quite ironic. I've done nothing more than tell you how the MQA filters have been determined to work (with a logic analyzer applied to the internals of a DAC). Yet I'm the one who won't accept this information because I've already decided?

[botrytis]

We always quip about the garbage in -> garbage out idea but there is also In -> garbage process -> garbage out . Which one is the actual faithful reproduction - I know what I would pick, not the latter that is for sure.

 

Which way do we want it - the way we have it now or with mqa? This is the way I see it.

 

It is like preferring tube amps over SS, etc., it is all just preference. I don't care if mqa is out there, just let me decide if I want it in my equipment or not. That is all I am asking. The DACs, I own, do not have it on the DAC chip or R2R, so it is on FPGA chip. That microcode can be dropped, give users a choice. Some will keep it, some will not, give US the BUYERS the choice, we paid for it after all.

[Jud]

3 hours ago, John_Atkinson said:

 

Incorrect. My 2018 article on A/D conversion - https://www.stereophile.com/content/zen-art-ad-conversion -  gave an example of how this was achieved using an A/D converter with a slow-rolloff antialiasing filter (a dCS 904's F4 filter) and a D/A converter with a slow-rolloff reconstruction filter (an Ayre QB9's Listen filter).

 

John Atkinson

Technical Editor, Stereophile

 

The key here of course as you well know is the A/D filter. Since it's slow rolloff it doesn't produce ringing, and thus there was no "time smearing" for the Ayre DAC's Listen filter to clear up. In other words, MQA can only "correct" time smear when there's none to be corrected.

 

There are at least 3 potential problems here, 4 for me and other Vandersteen owners:

 

1 - How many recordings are done with slow rolloff filters so there's little or no ringing? Very very few, I'd wager.

 

2 - With very little reduction of ultrasonics at either the ADC or DAC, intermodulation distortion is elevated.

 

3 - If you begin the rolloff early in order to try to get rid of ultrasonics, you're cutting frequencies in the audible range.

 

4 - The imaging qualities of Vandersteen speakers depend in part on their linear phase crossovers. Minimum phase filters change the phase of the signal (that is, there is group delay) and thus interfere with the imaging.