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MQA is Vaporware

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4 minutes ago, church_mouse said:

For the non-experts, like me, is this suggesting that if we want to start screwing up our music then get the MQA version. However, if you want to complete the job make sure you get an MQA Dac too?

 

Kind of a ‘‘double whammy‘‘.

That's one way of putting it. Not a bad one either.

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6 minutes ago, psjug said:

JA seems to agree that the results are valid.  But I assume he still maintains that leaky filters are OK because the impulse response is so visually appealing.

 

Actually, it is the fact that listeners seem to tend to prefer the leaky DAC reconstruction filters with most kinds of music. Certainly on my commercially released recordings, which people seem to like the sound of, I use the Ayre QA-9 set to "Listen," which has a slow-rolloff antialiasing filter, as the master A/D converter. The possibility for there being some low-level aliasing energy seems to be offset against the better time-domain performance. See the discussion of this trade-off at https://www.stereophile.com/reference/104law/index.html

 

Regarding the behavior of the upsampling performed by the renderer, I assume this will depend on which MQA filter is being used for the upsampling. Perhaps mansr could tell use which one is specified in his file's embedded MQA data? If a filter isn't specified in his data, then the spectral contamination will depend on which upsampling filter the renderer selects as its default.

 

John Atkinson

Technical Editor, Stereophile

 

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6 minutes ago, mansr said:
14 minutes ago, John_Atkinson said:

Regarding the behavior of the upsampling performed by the renderer, I assume this will depend on which MQA filter is being used for the upsampling. Perhaps mansr could tell use which one is specified in his file's embedded MQA data?

It's filter 4. When I checked over 100 tracks on Tidal, this was used by 70% of them.

 

Thanks.

 

John Atkinson

Technical Editor, Stereophile

 

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23 minutes ago, John_Atkinson said:

Actually, it is the fact that listeners seem to tend to prefer the leaky DAC reconstruction filters with most kinds of music.

At least those of us peasants can still select a different filter with Ayre and other non-MQA music / components 😁 

 

Also, by saying "listeners" you mean more than two or just two? 😁


Founder of Audiophile Style and Superphonica

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2 minutes ago, The Computer Audiophile said:

Also, by saying "listeners" you mean more than two or just two? 😁

 

My own experience leads me to prefer "leaky" reconstruction filters for most kinds of music; as does that of some of Stereophile team of reviewers; as does that of readers with whom I have discussed the subject. I don't see why anyone would have a problem with people citing their own experience as a reason for having a preference.

 

John Atkinson

Technical Editor, Stereophile

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4 minutes ago, John_Atkinson said:

 

My own experience leads me to prefer "leaky" reconstruction filters for most kinds of music; as does that of some of Stereophile team of reviewers; as does that of readers with whom I have discussed the subject. I don't see why anyone would have a problem with people citing their own experience as a reason for having a preference.

 

John Atkinson

Technical Editor, Stereophile

Agree. I have no problem with it. Sometimes it's all we have to go on, but it only carries the weight of what it is. 


Founder of Audiophile Style and Superphonica

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1 hour ago, mansr said:

The spikes at 66 kHz, 76 kHz, and 96 kHz are the result of intermodulation between the 10 kHz and 86 kHz frequencies.

 

Surely the spikes at 66 kHz and 76kHz are simply the images of the 30 kHz and 20 kHz harmonics, respectively?

 

1 hour ago, mansr said:

No idea what's going on at 94 kHz. Anyone care to speculate?

 

Nothing of interest, as far as I can see. Did you mean ~70 kHz and ~90 kHz?

 

Edit: I was looking at @vortecjr's FFT.


Phasure Mach III audio PC -> HQPlayer/XXHighEnd @24/705.6 -> Phasure NOS1 DAC -> First Watt F5-cloned mono amps -> Tune Audio Anima horn speakers

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48 minutes ago, John_Atkinson said:

 

Actually, it is the fact that listeners seem to tend to prefer the leaky DAC reconstruction filters with most kinds of music. Certainly on my commercially released recordings, which people seem to like the sound of, I use the Ayre QA-9 set to "Listen," which has a slow-rolloff antialiasing filter, as the master A/D converter. The possibility for there being some low-level aliasing energy seems to be offset against the better time-domain performance. See the discussion of this trade-off at https://www.stereophile.com/reference/104law/index.html

 

Regarding the behavior of the upsampling performed by the renderer, I assume this will depend on which MQA filter is being used for the upsampling. Perhaps mansr could tell use which one is specified in his file's embedded MQA data? If a filter isn't specified in his data, then the spectral contamination will depend on which upsampling filter the renderer selects as its default.

 

John Atkinson

Technical Editor, Stereophile

 

 

As one president said to another, "There you go again"

 

1)  What "listeners"?  Certain audiophiles with tipped up systems who like their HF blurred/distorted because it sounds "real" to them?  I also occasionally listen to music with min phase (i.e. out of phase) filters, but then I don't falsely tell myself that I am listening to a "better time-domain" waveform because the opposite is true

 

2) Are you confusing the performance of a single DAC (a sample of one) with a trend in listeners preferences?  Is the linear phase filtering on the Ayre QA-9 that bad?  

 

3) Explain to us, exactly, how min phase filtering is in fact "better time-domain performance".  You will of course have to start at the beginning (i.e. defining terms, etc.), and not these peculiar Stereophile/audiophile assumptions about "time domain" vis-a-vis min phase filtering you assume.


Hey MQA, if it is not all $voodoo$, show us the math!

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7 minutes ago, manisandher said:

Surely the spikes at 66 kHz and 76kHz are simply the images of the 30 kHz and 20 kHz harmonics, respectively?

No. Non-linear distortion can only happen after the interpolation filter where the imaging occurs.

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3 minutes ago, crenca said:

Ok, you like the distortion of min phase filtering. 

 

If you say so.I always find it amusing when someone trues to "prove" that some else's preference is wrong. 🙂

 

John Atkinson

Technical Editor, Stereophile

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5 minutes ago, mansr said:

No. Non-linear distortion can only happen after the interpolation filter where the imaging occurs.

 

It looks obvious to me that the spikes at 56 kHz, 66 kHz and 76 kHz are images of the harmonics at 40 kHz, 30 kHz and 20 kHz, respectively. (Much easier to see on @vortecjr's plot.)


Phasure Mach III audio PC -> HQPlayer/XXHighEnd @24/705.6 -> Phasure NOS1 DAC -> First Watt F5-cloned mono amps -> Tune Audio Anima horn speakers

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Just now, crenca said:

Which is it?  Is it objective "better time domain performance"

 

Yes, a minimum-phase reconstruction filter offers better time-domain performance, for the reasons I outlined in my 2011 Richard Heyser Memorial lecture to the AES. Google will be your friend here.

 

Just now, crenca said:

or is it just a preference

It is also my preference, as it is for the others I mentioned a few message back.

 

Just now, crenca said:

and distortion?

 

I don't see why a filter having minimum-phase behavior is in itself a "distortion."

 

John Atkinson

Technical Editor, Stereophile

 

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14 minutes ago, manisandher said:

It looks obvious to me that the spikes at 56 kHz, 66 kHz and 76 kHz are images of the harmonics at 40 kHz, 30 kHz and 20 kHz, respectively. (Much easier to see on @vortecjr's plot.)

Although images of those frequencies would land there, that isn't what is happening. At the time of the digital interpolation, the harmonic distortion hasn't happened yet, so there's nothing at 20/30/40 kHz to create such images. The non-linear distortion (harmonic and intermodulation) only occurs in the analogue circuitry.

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4 minutes ago, mansr said:

Although images of those frequencies would land there, that isn't what is happening. At the time of the digital interpolation, the harmonic distortion hasn't happened yet, so there's nothing at 20/30/40 kHz to create such images. The non-linear distortion (harmonic and intermodulation) only occurs in the analogue circuitry.

 

Yep, I see what you mean. Still, it seems strange that the intermodulation distortion in the analogue circuitry sits exactly at 56 kHz, 66 kHz and 76 kHz.


Phasure Mach III audio PC -> HQPlayer/XXHighEnd @24/705.6 -> Phasure NOS1 DAC -> First Watt F5-cloned mono amps -> Tune Audio Anima horn speakers

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