Jitter Correlation to Audibility

Feb 3, 2014 at 8:12 PM Post #227 of 361
I really do not understand all about jitter when analog devices introduce far more distortions (and usually easily audible unlike jitter).
 
Feb 4, 2014 at 1:57 PM Post #229 of 361
What are you basing your statement that jitter causes audible distortions on? There's no indication at all that jitter in the amount found in even the cheapest home audio products is even close to being audible.
 
Perhaps you are thinking of 24/96 recordings that have high levels of super audible high frequencies. Those can create analogue distortion in the audible range in some cases.
 
Feb 4, 2014 at 2:38 PM Post #231 of 361
If we can't hear it, it doesn't matter at all.
 
Feb 4, 2014 at 3:40 PM Post #233 of 361
  Some can't hear a difference, some can. How can we say it doesn't matter at all?


Because as far as we can rationally tell, no one can hear it at the common levels.  There are those who claim to hear it, but only are able to do so when they know what they are listening to and attribute differences to one component over another.  That ability 'mysteriously' disappears when they are blind to what is reproducing what they hear. 
 
Hence, no one can really hear it so it doesn't matter.
 
Feb 4, 2014 at 4:17 PM Post #234 of 361
 
Because as far as we can rationally tell, no one can hear it at the common levels.  There are those who claim to hear it, but only are able to do so when they know what they are listening to and attribute differences to one component over another.  That ability 'mysteriously' disappears when they are blind to what is reproducing what they hear.
 
Hence, no one can really hear it so it doesn't matter.

 
Mighy powerful statements - precise manifestation of ignorance.  These effects are real (analytically and physically), and only reason majority may not perceive it is because somebody understood the problem and has addressed it (or most of it) already.
 
Blind statements such as "jitter doesn't matter" is pure unadulterated ignorance by those who should search for conversations elsewhere.
 
Feb 4, 2014 at 4:30 PM Post #235 of 361
even indirectly inviting people to leave a thread because you disagree with them is not convincing of your position's value - and likely in violation of head-fi's policy
 
the "some can" need to do so in controlled DBT listening tests in front of skilled investigators if the claim is to have weight in the Scientific community
 
Feb 4, 2014 at 5:39 PM Post #236 of 361
  the "some can" need to do so in controlled DBT listening tests in front of skilled investigators if the claim is to have weight in the Scientific community

 
Conversely, those claims that it doesn't matter should be subjected to the same listening tests before their proponents make announcements that it doesn't matter.
 
Feb 4, 2014 at 7:41 PM Post #237 of 361
   
Conversely, those claims that it doesn't matter should be subjected to the same listening tests before their proponents make announcements that it doesn't matter.

 
There have been several DBTs of Jitter in studies, the key papers have been cited elsewhere they are the 1974 BBC paper (Manson)  http://downloads.bbc.co.uk/rd/pubs/reports/1974-11.pdf, the 1998 Dolby Labs paper available via the AES (Benjamin and Gannon) and the 2005 NHK (Japanese broadcaster) paper Ashihara et al. https://www.jstage.jst.go.jp/article/ast/26/1/26_1_50/_pdf  None of these placed the audible threshold for any kind of jitter below 10ns in any circumstances and no less than 20ns for music. There are a few pathological digital audio devices that can produce more than 10ns jitter but their performance is generally so poor that the jitter is the last thing you will worry about with them, the legendary MacIntosh MS750 music server being one discussed in the thread...http://www.stereophile.com/content/mcintosh-ms750-music-server-measurements
 
Here is a graph from the B and G paper showing the effect of jitter
 

 
the distortion product of adding a massive 300ns sine wave jitter is about 55 - 60db down on the fundamental, the 100ns jitter addition has a product a further 7db down, 10ns jitter would be even further down than that..B and G don't even bother with sub ns jitter, maybe somewhere there is someone with such superhuman hearing that it might be audible but if such a person existed they would be so many standard deviations from the mean that no rational hifi manufacturer would design products for them
 
Feb 4, 2014 at 7:55 PM Post #238 of 361
smile.gif

 
Feb 4, 2014 at 8:09 PM Post #239 of 361
  Some can't hear a difference, some can. How can we say it doesn't matter at all?

 
You keep bouncing back and forth from inaudible to audible. What makes you think that jitter at the level it occurs in home stereo equipment is audible to anyone?
 
Here is the chart that Ethan Winer posted a few posts ago...
 

 
Note that with really, really bad jitter of 1 ns, it is down below the noise floor of redbook for all but the very highest frequencies. Even with 10 ns, which is pretty much unheard of, the jitter noise is down 80dB below the signal. Good luck hearing any of that. No human being can.
 
Feb 4, 2014 at 8:14 PM Post #240 of 361
   
Jitter causes audible analog distortions.   The distortions of high precision analog components can be extremely small. It's all relative.

 
The finest turntable in the world perfectly setup with a superb cartridge cannot get within a country mile of the low levels of time related distortion of even a bog standard $350 Marantz Cd player, for instance here is the effect of speed issues with a souped up Linn Sondek turntable
 

Look at the skirts !
 
here is the same 1K played back via a Cd5004
311Marfig3.jpg

 

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