Quote Originally Posted by Marco View Post
The electrical components used on the board combine to perform the function of the clock upgrade, and so their effect can't be assessed individually. It's cumulative, thus the board acts as one part (replacing the existing 'gubbins'), and so that's how its effect is assessed.

Obviously I can't say for certain if the clock upgrade factually reduced jitter, as I didn't measure it (although Mark may have on his test bench), but since you're a fan of technical studies, there are plenty around*, documenting evidence of clock upgrades reducing jitter in the digital domain, for me to believe that they're intrinsically linked, notwithstanding numerous testimonials from people, such as Neal, who've had first-hand experience of carrying out such upgrades themselves, and of course my own.

In that respect, it would certainly have been interesting to have taken some pre and post clock upgrade jitter measurements, and I'll ask Mark if he did, and what his views are on the matter, as I'd be confident that results would've backed up what my ears clearly indicated. The bottom line though, is that the clock upgrade carried out to my Sony DAC fundamentally improved its sonic performance, which demonstrated that there was mileage to be had in that area, even with 'flagship' gear, as indeed there will almost certainly be with any of your CDPs.
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no - paper you linked to does not document a clock upgrade reducing jitter. That aside I am not disputing that a clock upgrade could reduce jitter. My points are 1) Jitter was almost certainly inaudible to begin with so even if you reduce it further you will not gain any audible benefit. 2) That the process of modifying the DAC could introduce changes in the sound unconnected with the level of jitter.

Without more controls there is no way to say that the reduction in jitter created the subjective improvement in sound quality.


I think Mark is unlikely to have made any measurements but it would be interesting if he has.


Both you and Gaz are far overestimating the effect jitter has on the sound and our ability to hear those effects. And are therefore erroneously concluding that the beneficial effects of the modifications you made are due to reduced jitter. The vast bulk of the evidence indicates that whatever improved the sound it was not a reduction in jitter.

Here there are some files with various amounts of jitter added http://archimago.blogspot.com/2018/0...me-jitter.html

If you can't be arsed to read it all and listen to the files here's the conclusion (my bold):

For me, even with a synthetic sweep, it took >100ns of cumulative sinusoidal jitter in the frequencies used (+/-225Hz, +/-1125Hz, +/-2475Hz distribution with decreasing amounts for each as above) before I could hear distortion! This is obviously a level of sideband distortion significantly beyond what we see with CD/DAC measurements. As I said a couple weeks ago, finding jitter distortion is certainly not impossible out in the wild... But it will be like looking for the giant panda. You'll only rarely find it when you know where to look.

Over the years, I have discussed my suspicions about devices like "regenerating" USB hubs, "purifiers", passive filters, doubts about digital cables of normal length supposedly capable of reducing jitter, and I've read articles from folks who seem to find (and hear) jitter everywhere! The designers and manufacturers have had every opportunity to demonstrate that these devices are able to do something to improve sound quality. The fact that they don't show objective results for their products and in fact essentially ignores calls to produce evidence when confronted is telling