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MQA Software / Hardware Decode Etc... Questions


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wklie thank you-what do you mean by 'power cycle' the ME2 and do you means just restart the mini or shut it down and then restart if the latter how long do I keep it off for.

I sort of did what you are suggesting but didn't do the power cycle part. Will retry with your suggestions -what dangers if any are there in uninstalling A+ and reinstalling it-Damien didn't suggest I do that.

thanks for responding bobbmd

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I guess, because you could get the software decoding part when playing from apps that don't do SW decoding, e.g. Mobile apps or anything other than Tidal, Audirvana + V3 and later Roon.

I don't understand.

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Hi Guys - I'm writing up my MQA article on hardware and software decoding. I know there have been some attempts at explaining how it works, but I also know there have been many more questions as to how it works.

 

Please post questions about software and hardware decoding in this thread and I will address them in my article. If I don't have the answer, I'll talk to MQA ltd. and get the answer.

 

I'm seeking the facts and trying to help everyone. I'm not interested in the arguments about MQA. Those are for another thread.

This is my interpretation of what has been said/written so far:

1- First unfold is not DAC dependant - it unfolds to 2x original sample rate (ie to 88 or 96). This is the part that is implemented in software in the TIDAL app

2- Second step is actually mostly upsampling to a higher sample rate. This part IS DAC dependant, it is where the upsampling parameters are tuned to the DAC, and thus it is restricted to hardware. No particular reason it should be restricted to hardware frankly, but since this is where MQA has decided to add DAC specifics then that's what it is.

 

So my first question is whether my interpretation is close to reality.

 

My second question is related to the software decoded stream - is there any MQA info/marker in it? I presume there is bc the renderers would need some sort of marker to identify an MQA 88/96 stream vs others. Is there anything else?

 

Third question: Since the Dragonfly is capped at 96, what is it doing as a renderer? Is this just to indicate the file is MQA (ie a blue light)?

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Audio Note Kondo Ongaku > Avantgarde Duo Mezzo

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wklie thank you-what do you mean by 'power cycle' the ME2 and do you means just restart the mini or shut it down and then restart if the latter how long do I keep it off for.

I sort of did what you are suggesting but didn't do the power cycle part. Will retry with your suggestions -what dangers if any are there in uninstalling A+ and reinstalling it-Damien didn't suggest I do that.

thanks for responding bobbmd

 

Hi. I see you've got several of these posts in different threads. When I was first considering a purchase of an E2, I noticed a higher than normal (at least what I would consider normal) number of posts from people detailing the premature demise of their unit (see here).

 

This one is typical:

 

My second one just died. Amazon let me return the first some time after the first thirty days and was refunded, minus a restocking fee. Now, about six months later, my second one has died. I really did enjoy the sound, crystal clear through a set of etymotic er4's, but we'll have to see how Meridian responds. I've emailed them directly this time.

 

Originally left this is a comment to another review, but want to make sure as many people see this is possible. Sounds great, but there's either something wrong with me or this product. It's never been wet or dropped. Both times one of these died, I unplugged it and plugged it back in because the sound was coming from my laptop speakers rather than the DAC and it just quit on me.

 

Not trying to be Debbie Downer, but you should consider the possibility that yours is bricked as well. I'm thinking it's just a matter of time before mine bricks too. Looks like Meridian has a quality control issue.

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Since the Dragonfly is capped at 96, what is it doing as a renderer? Is this just to indicate the file is MQA (ie a blue light)?

 

Compensation for DAC profile in order to eliminate DAC-side pre-ringing and post-ringing, i.e. de-blurring.

 

MQA music already had ADC (recording equipment) compensations incorporated, regardless of whether you use any form of MQA decoding or leave it undecoded. However, to get the full benefits of MQA, you need compensations for both ADC and DAC - the latter of which requires a hardware MQA full decoder or MQA software decoder + hardware MQA renderer.

 

The DAC-side compensations cannot be done in Tidal desktop app or Audirvana, as you already know that the first unfold to MQA Core is DAC-independent, and for those who expect this to be done entirely in software without buying MQA hardware - how could the software knows all the profiles of all the brands and models of all DAC in the market?

Peter Lie

LUMIN Firmware Lead

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This is my interpretation of what has been said/written so far:

1- First unfold is not DAC dependant - it unfolds to 2x original sample rate (ie to 88 or 96). This is the part that is implemented in software in the TIDAL app

2- Second step is actually mostly upsampling to a higher sample rate. This part IS DAC dependant, it is where the upsampling parameters are tuned to the DAC, and thus it is restricted to hardware. No particular reason it should be restricted to hardware frankly, but since this is where MQA has decided to add DAC specifics then that's what it is.

 

So my first question is whether my interpretation is close to reality.

 

According to my observations, that's pretty much it.

 

My second question is related to the software decoded stream - is there any MQA info/marker in it? I presume there is bc the renderers would need some sort of marker to identify an MQA 88/96 stream vs others. Is there anything else?

 

There is a small amount of metadata embedded in the decoded stream. It tells the DAC/renderer which filter to use and whether the audio bits have been scrambled.

 

Third question: Since the Dragonfly is capped at 96, what is it doing as a renderer? Is this just to indicate the file is MQA (ie a blue light)?

 

The microcontroller in the DF isn't powerful enough to do any sort of processing of the audio data. It can, however, program the ESS DAC with upsampling filter coefficients according the metadata in the incoming audio stream. Since the MQA-enabled firmware isn't yet available, this is obviously conjecture on my part, but it is based on what I know about the computational power of the microcontroller (it hasn't got much) and the content of the metadata supplied by the software decoder.

 

how could the software knows all the profiles of all the brands and models of all DAC in the market?

 

Same way every competent photo processing application knows the ins and outs of most cameras and lenses: through a database of parameters that can be updated online or with files provided by camera/lens manufacturers.

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SamuelTCogley: thanks I hope it is not a QA issue like I said E2 works flawlessly and absolutely sounds fantastic MQA no MQA on all the other platforms it sounds really good even on JRMC which I really abhor but used it to listen to some 2L downloads because that's where the downloads went (isn't strange?)

Am going to try what 'wklie' suggested he hasn't answered back yet - do you have any idea what he meant by a 'power cycle' of the E2?

I am awaiting the AQ DF Red.

I appreciate your comments and other responses to me and followed you through all those sometimes inane posts about MQA vaporware/I found a medical blog on medscape almost as absurd as this place is sometimes an article on american graduates vs foreign medical graduates(I am an American FMG and proud of it) if you think audiophiles are conceited/obnoxious/anal retentive/racist/opinionated/self righteous you ought to see how physicians and what I call 'SUITS' have to say on this subject

thanks again bobbmd

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Same way every competent photo processing application knows the ins and outs of most cameras and lenses: through a database of parameters that can be updated online or with files provided by camera/lens manufacturers.

 

. . . and since there are fewer than 10 DACs that support MQA out there, and all of them must be "certified" by MQA, pretty easy to keep up ;)

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There is a small amount of metadata embedded in the decoded stream. It tells the DAC/renderer which filter to use and whether the audio bits have been scrambled. The microcontroller in the DF isn't powerful enough to do any sort of processing of the audio data. It can, however, program the ESS DAC with upsampling filter coefficients according the metadata in the incoming audio stream. Since the MQA-enabled firmware isn't yet available, this is obviously conjecture on my part, but it is based on what I know about the computational power of the microcontroller (it hasn't got much) and the content of the metadata supplied by the software decoder.

Ok, that is actually pretty useful. Thanks.

NUC10i7 + Roon ROCK > dCS Rossini APEX DAC + dCS Rossini Master Clock 

SME 20/3 + SME V + Dynavector XV-1s or ANUK IO Gold > vdH The Grail or Kondo KSL-SFz + ANK L3 Phono 

Audio Note Kondo Ongaku > Avantgarde Duo Mezzo

Signal cables: Kondo Silver, Crystal Cable phono

Power cables: Kondo, Shunyata, van den Hul

system pics

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SamuelTCogley: thanks I hope it is not a QA issue like I said E2 works flawlessly and absolutely sounds fantastic MQA no MQA on all the other platforms it sounds really good even on JRMC which I really abhor but used it to listen to some 2L downloads because that's where the downloads went (isn't strange?)

Am going to try what 'wklie' suggested he hasn't answered back yet - do you have any idea what he meant by a 'power cycle' of the E2?

I am awaiting the AQ DF Red.

I appreciate your comments and other responses to me and followed you through all those sometimes inane posts about MQA vaporware/I found a medical blog on medscape almost as absurd as this place is sometimes an article on american graduates vs foreign medical graduates(I am an American FMG and proud of it) if you think audiophiles are conceited/obnoxious/anal retentive/racist/opinionated/self righteous you ought to see how physicians and what I call 'SUITS' have to say on this subject

thanks again bobbmd

 

My suggestion is to post a screenshot of your A+ "Audio System" settings. This might shed a little light on your situation.

 

Also, details on your current Mac OS version might be useful.

 

Regarding your last sentence, I have to own any animus I generate with my opinions. I personally think that learning is the key to "audio nirvana". But by learning, I don't just mean the technical aspects. There is consumerism, marketing and advertising in the mix, and those who embrace marketing and advertising as some kind of trustworthy source of information for consumers do so at their peril. This view is often seen as an "agenda" by those very people who trust audio equipment vendors implicitly. This is a predictable byproduct of the marketing and advertising's affect on a certain segment of the consuming public. To survive in contemporary society, one must have some understanding of how psychology is deployed against the population at almost every level. To me, this is simply another aspect of science and I fail to see an "agenda".

 

BTW, to "power cycle" your E2, you need only unplug/plug the USB connection. Good luck!

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Same way every competent photo processing application knows the ins and outs of most cameras and lenses: through a database of parameters that can be updated online or with files provided by camera/lens manufacturers.

 

The problem is how to get those parameters in the first place. While there is Adobe Lens Profile Creator for people to profile lenses, a DAC needs to go through the certification process to get its MQA profile done. If a DAC manufacturer did that, after the process it'd normally become MQA certified and its (hardware) rendering adjusted for it, negating the need for a software to have a database containing its profile.

 

One may argue if the whole thing is open rather proprietary, then things will be different - but this is a different discussion.

Peter Lie

LUMIN Firmware Lead

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Compensation for DAC profile in order to eliminate DAC-side pre-ringing and post-ringing, i.e. de-blurring.

 

MQA music already had ADC (recording equipment) compensations incorporated, regardless of whether you use any form of MQA decoding or leave it undecoded.

 

Where do you see any evidence of that expect of MQA marketing materials?

Where do you see evidence that any ADC related compensation was done with all old recordings, which are now available through Tidal as MQA?

How do you want to compensate if different ADCs were used in the recording process?

 

IMO currently the whole deblurring topic seems to be tales. The ADC type of compensation could be done with new music production, if MQA would be considered from beginning.

 

If the DAC side compensation is meant to be done by means of apodizing filters, then I will rather use HQPlayer for that.

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Hi Guys - Here's my article -> Computer Audiophile - MQA (for civilians)

 

I know I didn't answer all your questions, but some of them are better answered in different articles or in this / other threads.

 

I guess I was expecting a more technical article since those questions I have asked have not been answered anywhere else. Unless Bob Stuart comes and answers them, I don't know if anyone is going to figure them out. There was hope your connection to Bob could get all of these answered.

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Where do you see any evidence of that aspect of MQA

 

So far: not much indeed.

 

How do you want to compensate if different ADCs were used in the recording process?

 

Ironically, about half of the 'master' albums available on Tidal I looked at have a tell-tale droop at 22kHz or 24kHz. That means that these were either upsampled (i.e. fake), or that they originated at base rate (for instance a 48k multitrack) but were mixed and mastered at higher rate or to analogue tape (i.e. not fake, but not real hi-res either).

 

And those albums that appear to be true hi-res come out sounding not different from the original hi res downloads.

 

Impressions so far are that well recorded material in MQA sounds not better nor worse than its original, and badly recorded material in MQA sounds just as bad as the original. The majority I sampled so far sounds mediocre at best.

 

 

The ADC type of compensation could be done with new music production, if MQA would be considered from beginning.

 

Indeed. If it had any true benefit at all it could be done as a mastering step. And then everyone would benefit from it, not only those who paid for the blue light ;-)

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Since the promised article completely failed to address these questions, let me try instead.

 

-Would DACs that have a bandwidth limited interface but DAC chips capable of higher sampling rates actually be able to unfold to the full capability of the DAC chip? Example, Meridian Explorer 2 is limited to 192khz PCM playback, but the DAC chip it uses supports 384khz. So would a 2L 352.8khz MQA file unfold to 352.8khz resolution on this device?

 

Since virtually all DACs upsample to at least 384 kHz one way or another, so does an MQA DAC regardless of the original sample rate. The final upsampling stage ("rendering" in MQA newspeak) can in principle be done either in software on a DSP/microcontroller or by configuring the DAC chip's resampler with the MQA coefficients. The XMOS processor in the Explorer2 has the requisite performance to do it all in software, and measurements I've seen suggest that it does (the PCM5102 DAC chip also doesn't support custom filters). The Dragonfly, on the other hand, lacks the processing power to perform software upsampling, but its ESS DAC chip does support custom filters.

 

-What performance gain is there to using an MQA dac on 44.1khz MQA source material? The reason I ask is because there is no unfolding, so no advantage there that MQA brings. The ADC deblurring is already taken into account in the file, so non-MQA dacs would benefit from that already thus no advantage MQA dac would bring.

 

Presumably, you'd still get the benefits of the DAC-specific things they allegedly do.

 

-It seems software MQA decoders like Tidal are upsampling 44.1khz MQA source files to 88.2khz. Does hardware MQA also upsample source files originally 44.1khz to a higher rate internally in the DAC? If so, what rate would it run at? How would this be different from DACs that already internally upsample 44.1khz content anyway, like the Explorer 2?

 

The first decoding stage ("MQA Core") is identical whether done in software or "hardware." The difference between MQA upsampling and normal DAC upsampling is the interpolation filters used.

 

-MQA talks about having better temporal response than even high sample rate PCM files. Where does this benefit get applied? At the source file de-blurring stage such that it benefits all DACs? Or the dac profiled rendering stage? Or a combination of both of the previous? Or somewhere else?

 

They talk a lot, but I have yet to see actual evidence of any of that.

 

-In a 44.1khz source encoded as MQA, does it still have the temporal response MQA claims exceeds that of 192khz pcm? How does it achieve that?

 

At this point, it's just grand claims.

 

-In an unfolded MQA file, is the high frequency information restored exactly matching what a high sample rate PCM would achieve? Such that if we ignore the DAC profiling part of things, an MQA decoded file would sound the same as that same file with the same deblur corrections applied but delivered as high sample rate PCM?

 

No, the compression is lossy.

 

-The DAC profiling part of MQA is the piece that is not very clear how it works. Can this be explained in more detail?

-How does it work?

-Does it depend on analog circuitry of DAC or just digital behavior?

-Can this DAC compensation potentially be used regardless of input being MQA or plain PCM? If no, why not?

 

There is so far no indication that the profiling amounts anything other than sending MQA a large amount of money.

 

-What is the breakdown of the importance of each piece of the MQA chain in terms of contribution to the final sound quality?% DSP deblur of original source, % unfolding into high resolution, % rendering output with DAC profiling = 100% MQA quality

 

Nobody knows what the source "deblur" entails, if anything. The "core" decoding clearly restores some high-frequency content and removes some of the dither noise present in the compressed MQA file. Bypassing the compression entirely would obviously be better still. As for the rendering, my testing suggests you're better off without it.

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Was that supposed to be more than a regurgitation of the Bob Stuart blog post you took the diagrams from? It isn't.

 

The blog post was actually published after I completed the article, but before I published it.

 

You sure hate all things MQA and have a hard time with others enjoying it.

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The blog post was actually published after I completed the article, but before I published it.

 

OK. Either way, they're both essentially the same marketing blurb we've heard countless times before. You promised to get answers to questions posed in this thread, but I see nothing of the kind. That's rather disappointing. Perhaps MQA won't permit you to say more. I suspect that you've signed an NDA with them that regulates what you may say and also prevents you disclosing the existence of said NDA. It's how such companies usually operate. I don't expect you to confirm or deny this.

 

You sure hate all things MQA and have a hard time with others enjoying it.

 

I hate the dishonest way it is being marketed and how any voicing of legitimate concerns is met with ridicule and scorn, not only from MQA/Meridian but from the entire audio press (recall Michael Lavorgna's abusive behaviour a while back), yourself included. I wouldn't care about others enjoying it unless it threatened my ability for enjoyment of music without it.

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Unless it threatened my ability for enjoyment of music without it.

 

Well said Mansr! This is exactly my concern here.

 

While I am indifferent to the use of MQA from streaming sources like Tidal, I remain very concerned that MQA encoded albums will become substitutes for the non-MQA encoded PCM and DSD high resolution music available for purchase and download today.

Pareto Audio aka nuckleheadaudio

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OK. Either way, they're both essentially the same marketing blurb we've heard countless times before. You promised to get answers to questions posed in this thread, but I see nothing of the kind. That's rather disappointing. Perhaps MQA won't permit you to say more. I suspect that you've signed an NDA with them that regulates what you may say and also prevents you disclosing the existence of said NDA. It's how such companies usually operate. I don't expect you to confirm or deny this.

 

 

 

I hate the dishonest way it is being marketed and how any voicing of legitimate concerns is met with ridicule and scorn, not only from MQA/Meridian but from the entire audio press (recall Michael Lavorgna's abusive behaviour a while back), yourself included. I wouldn't care about others enjoying it unless it threatened my ability for enjoyment of music without it.

 

Give me a brake mansr.

 

Why don't you go through the questions in this thread and all the others threads, and see which ones are addresses. You'll find, if you want, many of them are addressed. I made a list of every one of them, and addressed the ones that fit the article. Plus, there are 1.5 million people who read CA. most of them don't enter the forum and many don't understand the technical discussion going on in the forum. If you didn't have blinders on, you would see quite a few nuggets of information in my article that aren't available elsewhere and don't come from MQA.

 

I haven't signed an NDA and the subject has never been discussed between myself and MQA Ltd.

 

Please direct me to posts where I've met legitimate concerns with "ridicule and scorn." Doing that is counterproductive to CA. I can't speak for other members of the press and don't really care what they write.

 

If you see this as your ability to enjoy music being threatened, that's on you. You refuse to take a test that could show you can't tell the difference between MQA and non-MQA, but you really really really enjoy saying MQA is inferior.

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Well said Mansr! This is exactly my concern here.

 

While I am indifferent to the use of MQA from streaming sources like Tidal, I remain very concerned that MQA encoded albums will become substitutes for the non-MQA encoded PCM and DSD high resolution music available for purchase and download today.

 

Are you concerned that you can only purchase Dolby or DTS encoded movies, and heavily DRM'd Blu-ray discs?

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Are you concerned that you can only purchase Dolby or DTS encoded movies, and heavily DRM'd Blu-ray discs?

Hi Chris,

 

Those are fair questions.

 

Clearly Dolby and DTS encoded movies enhance sound quality with the delivery of multi channel surround sound. By comparison, the SQ benefit of MQA is at best arguable and I certainly could hear no benefit comparing MQA decoded music with high resolution versions of the same tracks on my Brooklyn DAC. I believe there are many others here that have made the same claim. I purchased that DAC based on my belief that MQA was the future, and I was disappointed and later sold that DAC without any remorse.

 

If MQA encoded tracks played back on non MQA DACs at the same sound quality level as Redbook, I may be less concerned. However this always has seemed a dubious claim, and I am grateful to the others here who have confirmed through their research that the quality level produced from non-MQA DACs is indeed reduced from Redbook levels.

 

As for heavily DRMed Blu-ray discs, I only own a handful that were received as gifts from friends and family. Honestly I never watch them as I have been exclusively streaming movies for many years now. Indeed I recently took my working 200 disc Sony DVD jukebox to the Goodwill store as it was never used and took too much space to keep around.

 

So I am happy with purchasing either redbook or paying more for high resolution music downloads for those albums where it is desirable. Given my experience I don't need MQA and see no need for it except from streaming sources.

 

Like Blu-ray if my only choice is to purchase MQA encoded music, DRMed or not, my music listening will shift to streaming sources from my personal library. If the music industry wants to kill physical delivery of purchased music just MQA encode everything. That would be a sad day, but may be where we are headed.

Pareto Audio aka nuckleheadaudio

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