davehg Wrote: > in the January 1993 volume of Stereophile. The author, recording > engineer and now absolute sound editor Robert Harley, first explored > the scientific measurements of Ed Meitner, who first discovered a means > of measuring jitter. Meitner presented his findings to the 91st AES > convention, in a paper called "Time Distortions within Digital Audio > Equipment due to Integrated Circuit Logic induced Modulation. > > Harley references the following scientific journal article: > > Is the AES EBU/S/PDIF Digital Audio interface Flawed? by Chris Dunn and > Malcolm Hawksford. Dunn and Hawskford calculate that for 16bit > converters, a measurement of less than 100 picoseconds of jitter is not > likely audible, whereas a 20 bit conversion accuracy on the order of 8 > picoseconds in order not to induce audible (and measurable) > differences. This also assumes that the jitter is random; in many > cases, it appears consistently at the same frequency as the audio > signal. Also, in 1993, these engineers did not have access to 24 bit > converters, whose jitter measurements would need to be well below 8ps > given the mathmatical formula developed. > > Pat, I appreciate your healthy skepticism of the hi end, but as others > have noted here, jitter has a discernible and measurable impact on > audio frequencies, which is also easily heard. Less clear is at what > point the lowest measured jitter becomes relevant when all such devices > display incredibly low measured jitter. In the case of the SB3, its 55 > ps of jitter is one aspect of its sonic improvement when comparing > against typical transports which measure 200ps, especially when both > are using 24 bit or even 16 bit conversion.
The studies published by the Audio Engineering Society demonstrated that jitter isn't audible until around 20,000 ps. I am also of the opinion that the entire jitter problem was overhyped by marketers. They basically created a problem were there was none. If you are aware of any scientifically valid tests that prooves me wrong, please share it. Theoretical and Audible Effects of Jitter on Digital Audio Quality Benjamin, Eric; Gannon, Benjamin AES Preprint: 4826 Most audiophiles can't even articulate what jitter sounds like. That should be the biggest clue. -- FlyFishAndGolf ------------------------------------------------------------------------ FlyFishAndGolf's Profile: http://forums.slimdevices.com/member.php?userid=287 View this thread: http://forums.slimdevices.com/showthread.php?t=18116 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
