[esldude]

 
The vast majority of audio enthusiasts don't actually know what jitter is. But what they are told is that the product they are evaluating doesn't have it and that competing products have a detrimental amount of it. Some audio enthusiasts stop there and feel smart about themselves and their informed product selection. Others demand to be shown exactly how jitter affects output. Again they are presented with competing graphs - they are told that some look worse and some look better. They are told not to think about it too much, because it's far too complex to explain, but to use their ears. After all, what do we really know about jitter? It's like ****ing magnets, how do they work?
 
Yet there was still hope. A brave clan of enterprising young minds began secret investigations into the matter in the early twentieth century. Toiling away in secret labs of major telecom players of yore, your Ma Bells and your DARPAs, they discovered the secret lair of the jitter beasts. They fought valiantly and by the late 70s they thought they had defeated jitter through the advent of phase-locked loops. Alas, while they might have run the beast out of town, it was beaten and not dead. Jitter crawled its way to a deep dark cave to recuperate. There it was found by a group of trolls, some were withered husks of researchers who felt uncompensated and struck out on their own, others were trinket merchants looking for something shiny to peddle to the unwashed masses.
 
These trolls began to tell tall tales of the jitter beast having grown stronger than ever, of it hiding beneath the noise floor of the distortion graphs just waiting for an opportunity to strike unsuspecting listeners with its dreaded digititus. In truth the beast had licked its wounds and surrendered to a subsistence of scraps - a bad USB implementation here or an unstable crystal oscillator there. It no longer wished to face the fury of thousands of engineers grinding it down into the nether depths of Brownian noise.
 
Yet the villagers were scared, for each successive generation had been told of the monster by their parents. That if they were naughty and spent less than a thousand dollars on their transport the jitter would unleash the fury of a thousand Death Magnetics upon their ears. So the youngsters thought themselves wise and purchased jitter insurance from the elder trolls. Each one promised a lower period than the next - a nanosecond? Why you can get it down to a picosecond! A picosecond? Why with our current technology we can go femtoscale!
 
And so it was, perhaps in the same spirit of their right to bear arms that audio enthusiats purchased mighty DACs and Cables to whip the beast into submission (if they ever ran across it). Some would even hold championship contests where contestants would be sent into the field to see who could survive the beast's onslaught and be declared winner of the Snipe Hunt. The flaxen-haired golden-eared champions would pass their judgments onto the masses as sponsors of the order of the trolls, directing the purchasing decisions of puny losers.
 
Sadly the brave audio engineering knights had grown old and weary, they did not wish to fight a beast they knew had been slain, nor did they wish to interrupt or spoil the fantasy worlds of bright-eyed youngsters. Here we are -- everyone has heard of jitter but no one wishes to dust of the archival memoranda of the knights, for they know that as long as they spend enough they remain safe.
 
Even now I fear having told you of this ancient order, for I am but a simple bard who can't afford the Kingdom's tax on having an opinion. Even in this tucked away ghetto of sound science I fear the trolls will find me. Please, if I am no more after this post remember my tale.

Bravo!!!!  Best thing I have read on jitter in long, long time. 

 

[ab initio]

 
 

Spoiler: Warning: Spoiler!

The vast majority of audio enthusiasts don't actually know what jitter is. But what they are told is that the product they are evaluating doesn't have it and that competing products have a detrimental amount of it. Some audio enthusiasts stop there and feel smart about themselves and their informed product selection. Others demand to be shown exactly how jitter affects output. Again they are presented with competing graphs - they are told that some look worse and some look better. They are told not to think about it too much, because it's far too complex to explain, but to use their ears. After all, what do we really know about jitter? It's like ****ing magnets, how do they work?
 
Yet there was still hope. A brave clan of enterprising young minds began secret investigations into the matter in the early twentieth century. Toiling away in secret labs of major telecom players of yore, your Ma Bells and your DARPAs, they discovered the secret lair of the jitter beasts. They fought valiantly and by the late 70s they thought they had defeated jitter through the advent of phase-locked loops. Alas, while they might have run the beast out of town, it was beaten and not dead. Jitter crawled its way to a deep dark cave to recuperate. There it was found by a group of trolls, some were withered husks of researchers who felt uncompensated and struck out on their own, others were trinket merchants looking for something shiny to peddle to the unwashed masses.
 
These trolls began to tell tall tales of the jitter beast having grown stronger than ever, of it hiding beneath the noise floor of the distortion graphs just waiting for an opportunity to strike unsuspecting listeners with its dreaded digititus. In truth the beast had licked its wounds and surrendered to a subsistence of scraps - a bad USB implementation here or an unstable crystal oscillator there. It no longer wished to face the fury of thousands of engineers grinding it down into the nether depths of Brownian noise.
 
Yet the villagers were scared, for each successive generation had been told of the monster by their parents. That if they were naughty and spent less than a thousand dollars on their transport the jitter would unleash the fury of a thousand Death Magnetics upon their ears. So the youngsters thought themselves wise and purchased jitter insurance from the elder trolls. Each one promised a lower period than the next - a nanosecond? Why you can get it down to a picosecond! A picosecond? Why with our current technology we can go femtoscale!
 
And so it was, perhaps in the same spirit of their right to bear arms that audio enthusiats purchased mighty DACs and Cables to whip the beast into submission (if they ever ran across it). Some would even hold championship contests where contestants would be sent into the field to see who could survive the beast's onslaught and be declared winner of the Snipe Hunt. The flaxen-haired golden-eared champions would pass their judgments onto the masses as sponsors of the order of the trolls, directing the purchasing decisions of puny losers.
 
Sadly the brave audio engineering knights had grown old and weary, they did not wish to fight a beast they knew had been slain, nor did they wish to interrupt or spoil the fantasy worlds of bright-eyed youngsters. Here we are -- everyone has heard of jitter but no one wishes to dust of the archival memoranda of the knights, for they know that as long as they spend enough they remain safe.
 
Even now I fear having told you of this ancient order, for I am but a simple bard who can't afford the Kingdom's tax on having an opinion. Even in this tucked away ghetto of sound science I fear the trolls will find me. Please, if I am no more after this post remember my tale.

 

 
Tremendous post! +1
 
Cheers

 

[blades]

Entertaining post indeed.  Well written.  Our group went through a lot of trouble learning how to measure jitter in order to determine whether or not it was audible.  The measurement differences among various digital devices spanned an amazingly large percentabe of the tiny nano second bumps.  But, in the end we weren't able to detect an audible difference between any of them.  I'm afraid jitter belongs in the same category as cable skin effect at audio frequencies - real and measurable but inaudible and meaningless.

 

[Roly1650]

Excellent post......

 

[Lenni]

 

[anetode]

 

[castleofargh]

hercules and buddy jesus on the same page, maybe I should report you to admins for fight over religions

 

[blades]

Of all the bias controlled listening tests we did in the late '90's the most difficult one to conduct was jitter.  Measuring jitter isn't easy.  We had to develop some computer software that not only measured the jitter but also allowed us to adjust it.  To make a long story short, jitter isn't audible.  The point at which it finally became audible was way, way beyond anything you would find in a hifi component.  It is a great excuse for audiophiles to assign audible differences where none exist.  Hence its popularity.  Not an issue.

 

[Lenni]

please, can you describe what jitter sounded like on the sound track?

 

[bigshot]

I'd like to know that too. Jitter is such a rare beast, it might as well be a Jabberwock.

 

[blades]

  please, can you describe what jitter sounded like on the sound track?

If you are asking me the answer is it sounds like noise just like the noise you hear below the noise floor.  The timing errors were computer generated.  In order to get jitter noise above the threshold of audibility we had to go 1000's of times the jitter generated by any digital audio system in existence.  It is hard to remember the details but I believe when we tested a few systems, he never measured jitter more 100 db below the signal level.

 

[Lenni]

  I'd like to know that too. Jitter is such a rare beast, it might as well be a Jabberwock.

 
 

 
If you are asking me the answer is it sounds like noise just like the noise you hear below the noise floor.  The timing errors were computer generated.  In order to get jitter noise above the threshold of audibility we had to go 1000's of times the jitter generated by any digital audio system in existence.  It is hard to remember the details but I believe when we tested a few systems, he never measured jitter more 100 db below the signal level.

 
Well, I can tell you what jitter sounded to me the first I became aware of it. First was with a usb dac stick, and then even more so with a dedicated usb dac. The best way I can describe it is like small grains being removed from sound; it feeling more polished, clean. It’s not easy to describe really. Another way could be by taking an image that has no obvious flaws and looks perfectly fine, but only after using an image editor one become aware of the noise.
This was done entirely by listening (with ears) and comparing a dedicated dac and a pc as a source. I assume that what jitter is.

 

[cjl]

   
 
 
Well, I can tell you what jitter sounded to me the first I became aware of it. First was with a usb dac stick, and then even more so with a dedicated usb dac. The best way I can describe it is like small grains being removed from sound; it feeling more polished, clean. It’s not easy to describe really. Another way could be by taking an image that has no obvious flaws and looks perfectly fine, but only after using an image editor one become aware of the noise.
This was done entirely by listening (with ears) and comparing a dedicated dac and a pc as a source. I assume that what jitter is.

Unless you have measurements demonstrating an appalling level of jitter with your dac or PC, that sounds more like placebo to me.

 

[bigshot]

  Well, I can tell you what jitter sounded to me the first I became aware of it. First was with a usb dac stick, and then even more so with a dedicated usb dac.

 
Please let us all know the brands/models and jitter specs for these DACs, because I don't know of any current product with jitter in the audible range.

 

[Lenni]

  Unless you have measurements demonstrating an appalling level of jitter with your dac or PC, that sounds more like placebo to me.

 
lol...yeah placebo... more like magic mushrooms!
 

   
Please let us all know the brands/models and jitter specs for these DACs, because I don't know of any current product with jitter in the audible range.

 
M2tech hiface usb stick and M2tech Young dac. I don't know the jitter specs, but they're probably not different than other dacs of similar quality.