What does Jitter sound like?

Liudas,

True. Physically Jitter can ONLY exist once there is some form of clock or timing device...so a CD cannot have any jitter, however, if there is difficulty for a CD player to read a disc then perhaps oscillations in the drive motor power or lens focussing power might somehow cause the clock to be in error or more jittery (say for example they share the same power supply which happens to oscillate due to lens motor fluctuations, as it struggles to read a warped or uneven disc).

Shardorne, yes, you are right. I'm not too sure about the warped or uneven disc causing Jitter, though. My extensive experimentation shows that it is not this slow visible-to-the-eye movement of the lens which causes the Jitter one hears. Indeed, you can even put your finger onto a turning disc and you can cause a lot of low-frequency vibrations that way, but it isn't audible. What is audible then is if you go too far and cause a digital error. But Jitter itself is of a much more high frequency nature, as you say, such as from electronic oscillations and RF noise induction and the like.

Liudas

Shadorne - the positions of the pits in the CD are a form of timing information that can cause jitter as they are read. How this affects the PLL/buffering in the CD player depends on the design of the CD player. It is evidently important though. Rewriting a disk on CD-R with low jitter is an audible improvement on virtually all CD players I have tried. I mod a LOT of transports and players, so I get to try many different ones. This is good evidence that the pit locations are actually important.

Steve N.
Empirical Audio

Steve,

I woudl refer you to Nika Aldrich "Digtal Audio for teh Audio Engineer"

Quote:Page 353 "A digital recorder will store exactly the same information regardless of how jittery the clock"

Therefore according to Nika it makes no difference how many recordings or re-recordings or CD-R's you make.....ONLY a conversion to Analog or to Digital (where a clock is necessary) does jitter enter (from the clock).

A lot of people still seem to not buy-in to jitter effecting sound. I get the impression people think that since their PC software loads fine from a CD without error, then their audio CDs should too. But it's different. Perhaps someone can explain what's happening in 10 words or less. Jitter occurs at different places-at the place where a cd is read and then between any (every) 2 points in the circuitry. Anyone want to take a stab at how this effects sound? E.G. "The edges of the bits are not square because of X, causing some 1s or 0s to get missed" or "The edges of the bits get fuzzy, causing the dac to approximate some bits.". Then there is latency jitter. I'm not saying either of these is correct, just giving illustrative examples. I'm no expert; looking for the experts to chime in.