The jitter studies I have seen were inconclusive, poorly done, but still suggest humans can be sensitive to very minute levels of jitter. I don't think science will ever figure out in any meaningful way the conscious, let alone the subconscious, thresholds of audibility of jitter, because not only do they not care to use the correct test equipment or audio tracks, and they don't even know what type of jitter to use or have any appreciation of how to minimize false negatives, oblivious of what combinations of equipment, sound clips, and jitter to use to make jitter more audible or in what ways they should become audible, and they don't even know what to look for other than "HE SAYS HE HEARS IT".
If there is one type of auditory minutiae that humans can detect, it is time domain issues like jitter because humans have a very fine sense of time delays in order to help spatial positioning of sound sources, whereas humans may subconsciously "wash over" minutiae in frequency response, SNR, and THD, because it serves little purpose for humans to differentiate between such minutiae in the real world other than to attempt poorly designed ABX tests to amuse idiots who have no idea of how unscientific their tests are. Scientific bigots will never appreciate the possibility that when people experience the reduction of jitter in their audiophile gear, it may exist primarily as a subconscious awareness of the reduction of "wow and flutter" that may be as subtle as a "gut feeling" or "less fatigued feeling" which may be cumulative or take even over an hour to form, after which the listener might feel that the sound seems more "right", or possibly even worse if the reduction of jitter causes fatiguing sounds to become more pronounced. Nah, it's gonna be a bunch of smug-faced science bigots demanding that people subject themselves to highly unoptimal ABX tests designed to make people fail. Meanwhile, I'll enjoy my $500 jitter reduction box while audio science remains in the dark ages.
studies show that what most gears confront us with will usually be indistinguishable in ABX (so at best not very audible). at some point it becomes audible because it will start to change more than just the timing of high frequencies. and the higher the jitter the lower the affected frequency.
in that situation (so high level of jitter) we now might get something like the treble sound at maybe 16khz (as it should be) + some noise at -60 or -40 or say -20db in some real bad situations(obviously if it's already that bad at 16khz it's gonna be worst at 18khz and better at 14khz).
usually sounds at 16khz are rolled off, if not on the album(if it was from a vinyl it certainly is), then I better not have a "warm" amp, else it would mean more roll off here. then I have to use a headphone (I don't count IEMs, most don't have much sound if any at 16khz) that doesn't roll off itself.
so chances are that my jitter will affect some music that is already 5 10 or 20db lower than the mids or bass, and the noise generated in a real bad situation is still gonna be at -20 or -30db below that already lower sound. and then you add the fact that we are a lot less sensitive to trebles than we are to mids(when I try to make some equal loudness EQ with something supposed to be EQed flat-ishhh already I end up with around 25db difference compared to mids and that's my ears). that's why we tend to say that it is not gonna be audible, because in most normal situations, it will not be for one reason or another and usually an accumulation of reasons.
sure if you have the worst system with super high jitter and everything with boosted trebles, and a young man's hearing. then you might just end up hearing jitter at some point. people saying that jitter will not be audible aren't saying it's impossible, they're saying that it's unlikely while listening to music.
now your assumption about science and those people who seem to know nothing and do everything wrong, well someone might believe you, but even on the old videos from MIT, jitter seemed to be a very hot topic and they already know a great deal about it(more than I could understand at some point). but if you're ok with your delusion that somehow you or that one guy making your gear in a garage actually knows more than the people who made the components for that guy to use, then so be it. but it's really not that hard to know how much you're wrong. jitter has always been a concern and always will be and has been very much studied because as it happens, all of science and electronic doesn't turn around audio and jitter doesn't disappear as soon as you're making a computer instead of a DAC.
then about time delays, maybe you should read a little more of what those "amused" "bigot" "idiots" know about time delays. it would help you avoid talking crap as if you knew your stuff. positioning cues are a mix of signature and time delays, obviously the frequency response is so much affected by so many factors that it doesn't really mater and we have a hard time telling up and down in music when it's so precise in real life. for one guy the sound will go higher up then at some point start to go in front, or behind, it depends as much on the sound and our equipment as on the shape of our ears.
so what is left is time delays, yes! you got one! except that's time delays between left and right you silly willy. half the people can't tell when headphones have inverted polarity and that's a 180° "lag". jitter might be audible, but not for spatial positioning. try getting your reasons straight before you start getting angry at the universe.
also you might like to know that jitter is usually given in nanoseconds. when you use a crossfeed (that's actually used for positioning cues) you mix left and right with delays like 280µs for Mayer crossover(or something close). and it's not hard to find the time delay between left and right(again it has nothing to do with jitter in the dac as it will affect both sides identically) you take the size you head, sound is 340m/s, not hard stuff.
anyway you're using lags 1000times bigger with left and right differences as material to say that jitter matters ^_^. but yeah go ahead and point out all the little defects of abx being unscientific (it's a subjective test, it's not perfect because it uses human for measurement).
then you talk about subconscious "wow and flutter"... amazing!!!!! again the jitter we are talking about is how much? let's say 100ns(poor us). worst case scenario 20khz wave is 1/20000=50µs long (hope I didn't fail here^_^). so this very very bad jitter of 100ns in our equipment is also a 0.1µs jitter. it will move sideways the 20khz signal from 1/500th of it's own period. and you hear 20000 of those every second. you're gonna pretend you can interpret that magnitude of variation as wow and flutter? lol
let's save the day and pretend you were talking about vinyl and not digital streaming. maybe sometimes you should stop thinking theory to justify your opinions, and take a look at numbers, you might have to change a few of your opinions afterward.
what we may hear at some point is the noise generated by the slightly irregular signal(but that also depends on the type of jitter, a regular one does nothing at all). that's because by being late the wave ends up with an amplitude slightly different, what in sound translates in some noise added to the original signal. noise as I said much lower than the sound of the 20khz itself. and as we go lower in frequency the lag becomes less and less significant in regard to the size of one period of the wave, making it effectively meaningless. so my fun example was a worst case scenario where you could hear 20khz...
enjoy you 500$ jitter box, maybe it does something else and is still meaningful, but you obviously have no idea why you bought it.
some people buy paintings, I've been told it doesn't affect sound, yet I find it relaxing and less fatiguing than looking at the wall. you think I'm onto something here?
. ( I don't believe that a cpu or other components will affect much or at all either, a the psu might)
