jhm731;197354 Wrote: > FYI3- power supply noise is the biggest cause of jitter in digital > circuits.
WTF?! What gave you that idea? What about transmission line effects, crosstalk, ground bounce, PLL instability or data-dependency? I'll grant that PSU noise is a factor, but to state that it's the biggest cause of jitter, without qualification, is misleading bordering on irresponsible. In a break with the usual Internet tradition, I'm going to back that up with some actual measurements. Here are pictures of the SPDIF outputs from the SB3, and from a Marantz CD63 CD player: SB3: [image: http://www.cawte.nildram.co.uk/Jitter/sb3.jpg] CD63: [image: http://www.cawte.nildram.co.uk/Jitter/cd63.jpg] Hopefully if nothing else, that puts the quality of the SB3's SPDIF output into perspective! The actual edges are actually a bit sharper than shown - a limitation of my scope's bandwidth - but I actually struggled to measure any jitter on it at all. Compare and contrast that with the output from the CD63, which suffers dreadful data-dependent jitter - most likely caused by penny pinching on a capacitor in the digital output stage. THIS is a machine on which jitter-reducing mods might well have a clearly audible effect. (That's not to say that the SB3 wouldn't benefit too - but it should now be obvious as to why any improvements are going to be minimal compared to the gains which might be made by modding other source components). -- AndyC_772 ------------------------------------------------------------------------ AndyC_772's Profile: http://forums.slimdevices.com/member.php?userid=10472 View this thread: http://forums.slimdevices.com/showthread.php?t=34749 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
