Phil Leigh;623392 Wrote: > I get the analogy... I'd like more info from JS on how he measured and > what he measured. > In particular, what PSU was being used and did he measure jitter > changing on the s/pdif (I can see how the buffer-driven processing > activity can impact the analogue outs).
I can't measure jitter on the S/PDIF, the signal is too complex for my test equipment. I can only measure jitter on something simple like a clock. Unfortunately the jitter of the Touch is just below the jitter threshold of my test gear so I can't give direct measurements of jitter in response to any of Soundcheck's modifications. I CAN measure power supply noise on a spectrum analyzer. I built a very low noise differential probe to feed the spectrum analyzer. It started out life as a very low noise microphone preamp I built many years ago, it works great for this. I'm running the preamp off batteries to try and cut down on PS noise contaminating the readings. I don't remember exact numbers, but there was significant differences in the PS noise with buffer settings. The Noise comes in bursts (primarily with the buffer interrupt). With a large buffer the noise is long bursts but not very often, this gives rise to strong low frequency components. With the small buffer the bursts are much shorter and come much more frequently, thus much fewer and less intense low frequency components. John S. -- JohnSwenson ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=84742 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
