There are two kinds of jitter: sampling jitter and interface jitter.

Sampling jitter happens when there is an unstable clock during A-D
conversion. It is baked in and can never be corrected.

Interface jitter happens during a D-D transmission. When it it between 2
digital devices it is a non-issue as long as the samples arrive at the
destination device intact. Toslink, for example, is known to contain very
high jitter. When the destination is a D-A converter, jitter can be
problematic, however most quality D-A converters use some kind of
jitter-reduction mechanism which eliminate the problem.

There is a third kind of jitter that occurs during glass mastering, If I
recall correctly it has to do with spacing of the pits & lands, however as
long as it is within a specified tolerance it will be transparent the CD
playback mechanism.

-- 
Konrad Strauss 
Director of Recording Arts, Professor of Music
Indiana University Jacobs School of Music
http://mypage.iu.edu/~kstrauss
http://www.music.indiana.edu/departments/academic/recording-arts/






On 2/11/13 9:18 AM, "Tom Fine" <[log in to unmask]> wrote:

Can jitter be introduced on the A-D stage? As I understood Mike Gray's
posting, he was saying jitter
can be induced from the get-go, in the A-D process. Konrad, do you know
that to be untrue?

Also, I've been told by one of Sony's senior EE guys that it can be baked
into a glass master. As I
understand it, jitter can be induced any time the bits are clock-aligned
for whatever reason. I'm
not sure why that occurs in making a glass master, but a lot of research
was done on this back in
the 80s and 90s, at least that's my understanding from what the Sony guy
told me.

So, I think (but may have learned this wrong, I'm not an EE) that bits is
bits only when the bits
are kept absolutely intact and the timing-transmission is rock solid.

-- Tom Fine

----- Original Message -----
From: "Don Cox" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, February 11, 2013 8:54 AM
Subject: Re: [ARSCLIST] Audibility of 44/16 ?


> On 11/02/2013, Paul Stamler wrote:
>
>
>>> I'm calling BS on this statement. Bits are bits - a word is a
>>> representation of an analog voltage value. If you think analog
>>> sounds
>>> better than digital just say it, don't try to dazzle us with
>>> gobbledegook.
>>
>> That's not gobbledygook, it's a simplified description of jitter, a
>> known, measurable problem in digital transmission. Proper D/A
>> conversion depends on two things: getting the right bits, and getting
>> them at the right time. If they arrive at the wrong time due to
>> jitter, the reproduced waveform will be inaccurate. (The same
>> constraint applies to A/D conversion: it has to be done accurately --
>> the right bits -- and it has to be done at the right time -- which
>> comes down to jitter. Early digital systems were prone to jitter,
>> because no one had figured out that it was a problem in audio systems
>> (though data people knew about it). A couple of decades later the
>> situation was much improved; A/D and D/A converters are much better
>> these days, and one reason is that they have a lot less jitter.
>>
> But jitter is only relevant when you are _converting_ digital to analog.
> You are leaving the digital domain.
>
> So long as the data remains digital (and inaudible), bits are bits.
>
> Regards
> -- 
> Don Cox
> [log in to unmask]
>