Ianmac;579304 Wrote: > Can I ask if you measured the jitter on the SPdif output from a > Squeezebox/Duet combination with standard Wall wart and a Linear power > supply signal. > Can I also ask if you have done the same with Touch. > > many thanks > > Ianmac
I have done tests on an SB3 (not a Duet) and a Touch. I don't have the super expensive jitter testers these tests really should use (I can't afford them!). What I DO have has a threshold, the jitter has to be above that threshold to register at all. Once the jitter is above that threshold its quite sensitive to jitter changes. It does very well at measuring clock jitter but very poorly at measuring S/PDIF jitter, so I have used it to measure the clock jitter in the box. I need a different tool to measure the S/PDIF jitter (which I don't have) With the SB3 I have tried three different PS, the one that came with it, which was a very poor PS, the Touch PS and my homebuilt linear supply. In all three cases the jitter is significantly above the threshold of my test equipment. The jitter with the SB3 switcher is significantly worse than the Touch or linear supply . I could detect no difference between the Touch or linear supply. On the Touch I did not try the SB3 supply, just the Touch and linear supply. The Touch clock jitter is just below the threshold of my equipment with both supplies. I have done lots of other measurements on the supplies besides jitter measurements. I have found that the original SB3 supply injected a large amount of noise back into the AC main. The Touch supply is WAY better, but not perfect, it still injects a little noise back in the mains. The linear supply injects almost no noise at all into the mains. (which is NOT true of all linear supplies, but thats a whole different thread) I CAN hear a difference on the analog outs on both the Touch and SB3 when switching between the Touch and linear supply, but I'm not sure exactly what is the cause. I'm more inclined to think it has to do with the rest of the system responding to the small differences in noise injected into The mains than it is to changes in jitter. I have not done exhaustive testing on the digital out into a DAC as far as PS differences are concerned. Even if I had, the sensitivity to jitter of different DACs varies greatly, so any generalizations would be very hard to come by. John S. -- JohnSwenson ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=82128 _______________________________________________ Touch mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/touch
