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 audible using a 24 bit conversion, and comparing against typical transports which measure in excesss of 100ps. -- davehg ------------------------------------------------------------------------ davehg's Profile: http://forums.slimdevices.com/member.php?userid=2269 View this thread: http://forums.slimdevices.com/showthread.php?t=18116 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
