Mnyb;677563 Wrote: > God info . > That was what I meant (in to many words ) the result are -very- > different suggesting > > a measurement error > > b faulty sample > > c incomparable measurement methods (apples and oranges all over again > ) > > Or any combination of the above . > > C is a good guess ,The issue here is measuring jitter on the spdiff > reciever and other places internal in the dac makes it impossible to > asses compared to other measurements ? But nevertheless interesting, > But how does other sources fare using this method ? and what are the > ballpark expected figures for decent performance . > And how would it measure inside another DAC with different design ? > > And does it matter, if the DAC can fix it it's ok anyway ? > > It is an interesting piece of equipment , in my case I don't need a dac > , but it would be on my shortlist to try out if needed one . > Price/performance seems sane not the typical overpricing.
"C" makes sense to me. Most likely the answer is buried in the definition of jitter. The Anedio measurement (for example) is using FFT which will sum the terms against a specific carrier frequency, which is a form of peak-peak jitter at the test tone. Looking at the tester used by John W - the R&S UPD - it *seems* capable of measuring phase error (vs. internal reference) at the sampling clock frequency. And as long as it can sample over a long time period, it's much more harsh test than cycle-cyle jitter at (say) 11kHz. Although I confess I've not pored over the spec in detail, from my past experience of using a ~similar piece of equipment (HP 5372A) I *would* expect a much worse jitter number from the UPD, and more relevant to the audio performance that we're interested in. Happy to be corrected if my understanding of the peak-peak measurements is mistaken. -- Pete91 ------------------------------------------------------------------------ Pete91's Profile: http://forums.slimdevices.com/member.php?userid=53038 View this thread: http://forums.slimdevices.com/showthread.php?t=92112 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
