In reading about DACs the word jitter comes up a lot.
I looked at some info on jitter (eg
Wikipedia) and I'm wondering...
What does jitter sound like?
I know there are some websites that you can listen to music recorded at various bit rates (or you can rip the same song yourself to compare).
Is there anything similar to listen to what jitter sounds like at various levels?
I realize that going from file -> computer -> speakers may introduce it's own errors, but just to get a handle on what something really bad sounds like.
Mike
*EDIT*Links on "What does jitter sound like":- Altmann, Charles - Text and scope shots - link
- Audiogon thread and answers -
link
--- Quote: "At its worst, jitter is revealed as a hard, flat, fatiguing glare across the midrange & treble.
A low-jitter clock relieves strain and adds suppleness & body.
Further reductions in jitter get closer to analog-like treble delicacy, tighter bass control, and overall ease."
- Computer Audio Asylum thread -
link
--- Quote (John Swenson) (bold added):
"In general I find jitter to cause a loss in "inner detail" which usually relates to a "flatter" sound. It looses the "liveness", it becomes boring. Sometimes I find jitter also effects bass significantly. This is strange because I would expect high frequencies to be more susceptible, but I frequently hear a significant improvement in bass articulation when decreasing jitter.
Its hard to listen to a piece of gear and say "thats got high jitter" just by listening, because many other things can cause similar sonic effects. By building my own gear I've been able to do quite a few tests where I can hold everything equal except change jitter and can definately hear major improvements in sound by lowering jitter. But frequently similar changes can be had (for example) by upgrading the power supply of the preamp.
Another issue is all jitter is not the same. The spectrum has a lot to do with it. I have one receiver with 200 ps of jitter that sounds significantly better than another with 50ps, BUT the spectrum is radically different between them. Thus just picking the lowest published "jitter number" will not gurantee the best sound. Unfortunately you still have to listen!
I also have large misgivings about any system going through (the never to be sufficiently damned) S/PDIF interface. This is so frought with peril that its almost impossible to get a really good clock out the other end. This makes me very suspicious of "jitter reduction boxes" that output S/PDIF, they STILL have to go over the interface. Yes if the "transport" is really bad they can help, but its never going to get really good.
There are a few DACs that actually do an extremely good job of cleaning up the clock from a S/PDIF interface, but they are very few and far between. These are the only ones I would consider using with S/PDIF. And even then the jitter from the recovered clock has a tendancy to make itself heard through mechanisms such as ground noise and supply contamination, it takes a lot of work to keep it out of the final result.
John S. "
- Computer Audiophile thread -
link
- Stereophile Oct 1993 artcle By Rémy Fourré -
link
- Stereophile test CD # 2 contains an example of jitter
