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Jitter vs no-Jitter Part III


bibo01

Which is the track with LESS jitter?  

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Dear Friends,

 

After our first test "Jitter vs. no-Jitter" here it is another test, actually two, on our ability to recognize jitter.

 

Following the advice of the user "mitchco" We have prepared a file containing two songs by Marilyn Mazur & Jan Garbarek from the album "Elixir" - "Bell-Painting" and "Elixir" - for high and low range respectively, with high DR.

 

At the moment I do not want to give too much technical information, which will be given at the end of the survey. The two tests seem the same, but obviously they are not.

Both songs were recorded with two equal converters, but one was defective and produced much jitter.

 

In both tests we have to try to recognize the song with LESS jitter.

 

The poll will last one week only and it is published on three forums: NextHardware, ComputerAudiophile, WhatsBest.

 

For "Jitter vs. no-jitter Part II" the tracks can be downloaded from:

dropcanvas - instant drag and drop sharing - canvas view

or

https://www.dropbox.com/s/agbq0wizwa301au/Test%201.zip?dl=0

 

For "Jitter vs. no-jitter Part III" the tracks can be downloaded from:

dropcanvas - instant drag and drop sharing - canvas view

or

https://www.dropbox.com/s/pis3kp818onp168/Test%202.zip?dl=0

 

Good listening!

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I am curious about the tests and will try to download tomorrow, bibo01. Thanks for making these available. I don't particularly care if I choose correctly, I just want to try to get training across multiple files in how jitter sounds.

One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> optical to EtherREGEN -> microRendu -> ISO Regen -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

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We can call the double poll - Part II and III - as closed.

 

I thank all those who have taken part with their listening.

I thank Tom "Gefrusti" for the essential technical contribution.

 

------------------------

 

The password to open the file with the answer can be downloaded here: dropcanvas - instant drag and drop sharing - canvas view

 

The answer is:

Part II

Track A: Jitter OFF

Track B: Jitter ON

 

Part III

Track C: Jitter ON (like B but renamed)

Track D: Jitter ON + extra jitter.

 

------------------------

 

Bearing in mind also four votes that were given to me in private, the cumulative result of votes from three participating forums NextHardware, ComputerAudiophile and WhatsBestForum, is:

 

Part II

A: 13

B: 10

X1: 6

 

Part III

C: 10

D: 16

X2: 2

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In the two parts poll the tracks with less jitter were A and C - I try to give my own interpretation.

 

In Part II there is a slight majority for A, but not decisive; in fact, it tends to disappear when you consider as well that on the other side six votes did not perceive difference. Basically, this test was not easy to "pass", in the sense that the difference between the two files is not high.

 

In Part III the difficulty to perceive difference is reduced further (only 2 votes for X2. However, most of the listeners preferred file D, the one with more jitter and with opposite characteristics to A.

 

The position of Tom "Gefrusti" - my tech expert :) - about it is:

"... I think the differences are so nuanced that everyone (regardless of the time) interprets according to the "particular section" that is analyzing in the sound of the songs.

As it was a comparison that "flows" in real time, our perception system makes some frames at different times ... so the micro-variations in timbre//tone become misleading in what it should be a comparison of the same mirror segment of sound that you are listening.

I personally stopped playback in several places and I compared that with a mirror image of the other songs ... I have tried to listen carefully to all the details that make the attack, decay and tonal//timbre yield ... They seemed to me so alike that ... I just could not make repetitive and demonstrable what I was forcibly trying to perceive.

Is preference expressed at random? If the brain stores the spectrum into different time segments ... we will fight with spectrum yield completely at random.

If you notice, in our tests there has never been an overwhelming prevalence of a particular file ... instead it would happen if the differences went up gradually."

 

My personal theory, however, is that there is a difference in the way in which people express the pleasantness and/or the correctness of a piece of music.

Normally a listener does not listen in ABX. While listening, a comparison is made internally with listener's own idea of ​​music that is based on various personal references: experience, aesthetics, knowledge ...

IMHO, some people have a more cerebral approach to decision-making, perhaps combined with a knowledge of music, that establishes the correct sound of a song, and therefore determines the way they establish the perceived pleasure.

Other people, however, have an approach "with the belly" to decision making that is the opposite of the previous one: if the song is perceived as more pleasant, therefore it is the more correct.

 

I report my experience in regards to the tests which somehow corresponds to the "theory" expressed above.

I began from the first poll of a few weeks ago to see if there was direct consequence between the two tests, that is, the "thinner" song is the original with less jitter, whilest the song with more body has more jitter although subjectively "better".

My partner and I listened to the songs separately for 3 times in a row, "in the dark", that is, one was listening (only the first part - plin plin) while the other would change the song. Answering the question "the song with less jitter", we both made the same choices and, apparently, we have even guessed right because we voted A and C. For the record, however, if she had to express a subjective preference, my partner would have chosen B and D.

 

Comments ?! :D

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I believe I picked the one with more jitter each time. So I can't reliably A/B the sound of jitter, at least not without considerably more training if at all.

One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> optical to EtherREGEN -> microRendu -> ISO Regen -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

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Well what you have in these tests is an alternative choice test. The statistics for that are different than ABX. If you have enough responses (30) or so, 75% correct is the threshold for a 5% chance the result is not chance. That with 2 choices. Some will handle a test like this when you have choice of no difference by dividing the no difference votes equally between the two choices. Doing that your tests don't show the results reaching the 75% correct threshold.

 

The results would be cleaner if you had only two choices and not a no difference choice.

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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If the tests don't clearly demonstrate the detrimental effects of Jitter, then either the choice of material is poorly chosen or the methodology used is not capable of showing this.

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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If the tests don't clearly demonstrate the detrimental effects of Jitter, then either the choice of material is poorly chosen or the methodology used is not capable of showing this.

Material and methodology was suggested by a regarded user of this community.

Are you sure there are only two choices? Are you sure that the "responsibility" in on the test only and not on the user as well?

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Material and methodology was suggested by a regarded user of this community.

Are you sure there are only two choices? Are you sure that the "responsibility" in on the test only and not on the user as well?

 

I would have thought that the main purpose of these tests was to educate people, not further confuse them, as appears to be happening with these tests. If they don't, and even the person who started the thread here can't get them right either, as happened in the first lot, then the tests are a waste of time.

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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I would have thought that the main purpose of these tests was to educate people, not further confuse them, as appears to be happening with these tests. If they don't, and even the person who started the thread here can't get them right either, as happened in the first lot, then the tests are a waste of time.

 

There's education in failing to get these right. I now know the idea I'd formed about how jitter sounds from test 1 wasn't strong or accurate enough to get further tests correct. So further samples are necessary for training. I'm also cognizant of John Swenson's remark that the first test wasn't measuring what we thought it was. I'm curious to understand more about that, because if I propose to train myself, I want to do it with correct training materials.

One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> optical to EtherREGEN -> microRendu -> ISO Regen -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

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I do not think that this test is appropriate for perceiving "the sound of jitter". When most people talk about jitter in playback they are referring to the jitter in the DAC actually producing the analog signal they are listening to. This is NOT what is being tested here.

 

In these tests we have two identical DACs, with one with supposedly higher jitter. But "WE" the test takers, are not listening to the output of those two DACs. For us the analog out of those DACs are sent to an ADC, which converts back to digital, that digital gets sent (somehow) to OUR DACs which generate another set of analog signals, which are what we are actually listening to.

 

The jitter in OUR DACs does not change when listening to the different tracks, so we are not actually listening to jitter. Think about what is happening here, the analog outs from the two original DACs are converted to digital by an ADC with its own jitter and its own digital filter. That goes to a DAC with ITS own jitter and digital filter. What is the probability of this chain faithfully reproducing the small differences in analog out from the two original DACs due to a jitter difference? I would say pretty small.

 

So what I think we are actually hearing is how jitter affects the interactions between multiple digital <-> analog conversions, NOT the effects of jitter itself.

 

So I don't necessarily believe that people prefer the jitter, but that the jitter is acting as a kind of dither in the multiple conversions.

 

This test really needs to be done on the actual analog outs of the two original DACs in order for it to really be about the "sound of jitter" rather than the effects of jitter on multiple conversions.

 

BTW I chose B and D. I have built many different DACs for which I do know which has higher and lower jitter, the differences I hear in B and D are similar to what I hear with lower jitter DACs. It is interesting that D sounded the best (by a fairly high margin). I need to try an experiment where I add a little bit of digital dither before the upsampling filter in one of my DACs.

 

John S.

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Thanks John, the explanation is much appreciated.

One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> optical to EtherREGEN -> microRendu -> ISO Regen -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

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