what is jitter supposed to sound like?

Gmood1, you are definitely on to something. One effect of power supply noise and ripple is that it changes the threshold at which digital gates switch. This can have the effect of advancing or delaying a digital transition and thereby increasing jitter.

Jlambrick, Gmood1,
it is indeed correct to say that improvement in the digital & analog power supplies improves the sound. The less ripple there is in the power supplies & the better their ability to supply current helps in minimizing the perturbations to the electronics.

yet another effect that exacerbates jitter-like effects is the transport-DAC interconnect cable (when using separates). Most cables, I believe, are improperly terminated & result in reflections. This has some of the same effects as jitter - smearing the overall presentation.

the reason I said that I've not heard the sound of jitter is 'cuz poorly designed power supplies show up as nearly the same effects I stated above (music loses its snap, imaging not being precise, high freq being edgy/sharp/brittle) as the effects of jitter!
So, when one hears loss of low level details or poor imaging or sharp highs which effect is to be blamed? Excessive jitter or poor power supplies (or poor implentation) or improper interconnect length & terminations?
I have found it hard to separate the 2 issues, in general. I can probably zero-in for my particular CDP as I know which mods have/have not been done. However, when I audition a piece at a dealer or a show or at a friend's house I don't have such detailed info.
It's a toughfy for me as I find it hard to be conclusive: "this is excessive jitter!"

Bombaywalla, good point. I found that jitter was the problem in my system accidentally. I was building my first system in 20 years and everything was new (to me). I tried everything I could think of but the sound still seemed dull and lifeless. In desperation, I thought I would see what equalization might accomplish so I borrowed a dbx Quantum mastering processor. While it was still in bypass, the sound snapped into focus like I'd never heard before. I finally figured out that it was the huge reduction in jitter that caused the improvement. I've found a much more cost effective way of creating a low jitter signal now but the symptoms I was hearing could have come from a multitude of sources.