Originally Posted by stereoeditor
I offered a detailed answer to that question a couple of days ago. I thought what I wrote was clear; did you not comprehend what I wrote?
Originally Posted by spkr
You skirted around and avoided a direct answer.
Well, not really. I don't think that all measurements can be reduced to a single value. Manufacturers do that because it's easy and can allow their marketing department to point at one number as somehow being singular merit of quality or performance.
Take for example THD which is often really a combination of THD + noise. Is an amp with a THD of 0.5% better than one that has 0.02%? IOW could I hear that distortion? Without considering the spectrum, the various harmonics, that's a tough call. From what I've seen, most amps have a tailing harmonic distortion profile but if that's true for the first amp but the second amp has something like primarily 5th order distortion there'd be something that troubled you about it.
With jitter, especially as pertains to receivers, what the typical spectrum looks like is unclear. Myself, I haven't seen enough graphs to confidently say most jitter looks like this or like that. I'm talking about HDMI here. Amir has said, or I think he did, that most likely the jitter spectra he's presented are likely I innocuous. But I'm not so sure.
The reason I'm not so sure is because of a few reasons.
- The receivers are being tested while they're not hooked up to anything.
Amir observed that just adding a cable not hooked up to anything changed things.
JA found in some review that turning off the display lights made a significant difference.
What happens when an LCD or Plasma TV is hooked up and running?
Does being hooked up to speakers and/or a sub screw with the jitter profile?
What about engaging room correction?
What if the receiver is also powering another zone?
IMO, the measurements done by Miller, S&V, Stereophile, AH, or whomever haven't provided any information on in situ measurements. They're simply too idealized and not reflective of real world use. I think until such time as we get a better handle on things we are unclear how jitter and maybe other measurements even are affected when the receiver is in actual use. If we find that things are more or less the same, then Amir's statement that it's likely not audible seems reasonable. OTOH, if we find that the width under the central frequency starts looking like Kim Kardashian's fat ass, with a whole bunch of spuria and now that singular jitter number is 100x or greater, then it's time to say, hmmmm.