Jitter solution

[mike7877]

Again.... jitter would then still be determined by the clock everything is locked to.
I see no benefits, just a lot of complexity that still has drift and stability of the master clock and the jitter of the 3 PLL's that are then averaged just a little.
I have not seen clock circuits employing this strategy.

Jitter in practice is caused by the way digital signals are transported and steepness of the many gates in the total circuit etc.

The comparator would be a counter, not a clock
edit: plus what I put in post 23.

It's just an idea... I do expect to be wrong or for there to be a reason why it's not implemented. But in the off chance there's not, why keep it to myself, yanno?

 

[mike7877]

What is making you believe it is a problem that needs more attention?

Here is a site where you can listen to varied levels of jitter:

what does jitter ACTUALLY sound like?

In a previous post we had an encounter with jitter in audio. The talk about jitter is hard to miss these days. There are plenty of products on the mar...

www.sereneaudio.com

Jitter has to be pretty extreme before it is going to be an audible problem.

Why did RME improve jitter on the Babyface Pro FS vs. the non FS version?

I don't get why the underlying reason for improving something needs justification every time

 

[mike7877]

There are two things at play here: frequency accuracy and frequency stability. Only the last one is really relevant. That two clocks deviate in speed by let’s say 1ppm is irrelevant. You won’t hear the difference. But the jitter part is the frequency stability: how much does the clock deviate its frequency over time while maintaining a stable average frequency.

For the 3-clock scheme to even resemble a chance of working, you’ll need clocks with the exact same frequency accuracy. That’s is basically impossible to make. So, as soon as the clocks deviate, your lost.

The 3 clocks would be running off the main clock. When they line up with the main clock, the main clock is used, and when they don't, the 2/3 or 3/3 clocks would be used (for the DAC and to run themselves, and to reset the main clock to.

And the 3 clocks would be determined to be right when 2/3 or 3/3 of them had gone through 1000 cycles (because that's the ratio of the main clock to the 3 clocks).
edit for clarity: the 1000 cycles determined by counting, not a clock

 

[voodooless]

Just no!

 

[mike7877]

Just no!

* Has idea thinks may be beneficial, shares idea *

Rude!

 

[voodooless]

Rude!

No, rude is ignoring any and all arguments and still pretending you have something worthwhile.

 

[voodooless]

I don't get why the underlying reason for improving something needs justification every time

Because you call it “solution”. This implies there is a problem in the first place.

 

[mike7877]

No, rude is ignoring any and all arguments and still pretending you have something worthwhile.

OK, that's what I'm doing

 

[mike7877]

Because you call it “solution”. This implies there is a problem in the first place.

Since it's not perfect there's room for improvement...
If you don't want to address my ideas in post 21 and 23, there's nothing for you here.

edit: would the master clock not be corrected by the 3 slave clocks if configured in the way I suggest?
If not, please tell me why. I want to know, really, I do.
I said in a post I fully expect to be wrong or for there to be a reason this isn't implemented, I'm not coming from a point of "yall ar soooo dum, liek y didn't you think of tgis", so I really don't get the attitude. And you're not going to drag me down to your level by being combative. At this point you can discuss the topic at hand, or don't - I will only be replying things that are relevant.

 

[voodooless]

Really simple: since the clocks are not in sync, the distribution of the flanks will on average be a normal distribution as well. If you then use a majority vote to pick the “best” clocks, you’ll more jitter, not less. Worse, it will meander over time.

Just draw it out, and you’ll see.

 

[mike7877]

Redundant post, mods please delete or members please ignore lol

 

[mike7877]

Really simple: since the clocks are not in sync, the distribution of the flanks will on average be a normal distribution as well. If you then use a majority vote to pick the “best” clocks, you’ll more hitter, not less.

Just draw it out, and you’ll see.

Makes sense, thank you.

edit: I think I was coming from a point where a faster clock would have lower jitter, but the lower jitter clock could just be used in the first place, making all the other clocks and the comparator redundant and needlessly complicated

 

[sergeauckland]

Why did RME improve jitter on the Babyface Pro FS vs. the non FS version?

I don't get why the underlying reason for improving something needs justification every time

Because in so many cases, improvements in the measurements don't result in anything remotely audible, so not a problem that needs solving.

Jitter has for many years, if not ever in digital audio not been a problem that needs solving. Back in the dawn of digital audio, now 50 years ago, this was recognised and simple means like Phase-locked loops reduced jitter to totally inaudible levels.

If one thinks of what jitter actually is, i.e. what used to be called Wow and Flutter, i.e. a shrinking and stretching of time intervals, and how much W&F, i.e. jitter was already inaudible, around 0.1% i.e. -60dB or 1000ppm is many orders of magnitude greater than even the worse jitter in any audio product.

Just like reducing distortion to -100dB, or frequency responses out to 1MHz, totally unnecessary except for specsmanship.

S.

 

[fpitas]

Because you call it “solution”. This implies there is a problem in the first place.

The problem is that people aren't buying pointless audiophile de-jitter boxes. Think of the poor starving families of snake oil merchants!

 

[fpitas]

Like blaming the dog. And no matter how many times we explain the subject, it comes back.

 

[mike7877]

Because in so many cases, improvements in the measurements don't result in anything remotely audible, so not a problem that needs solving.

Jitter has for many years, if not ever in digital audio not been a problem that needs solving. Back in the dawn of digital audio, now 50 years ago, this was recognised and simple means like Phase-locked loops reduced jitter to totally inaudible levels.

If one thinks of what jitter actually is, i.e. what used to be called Wow and Flutter, i.e. a shrinking and stretching of time intervals, and how much W&F, i.e. jitter was already inaudible, around 0.1% i.e. -60dB or 1000ppm is many orders of magnitude greater than even the worse jitter in any audio product.

Just like reducing distortion to -100dB, or frequency responses out to 1MHz, totally unnecessary except for specsmanship.

S.

Of course I understand that jitter is inaudible in all decent modern electronics. I don't hear it in my RME Babyface Pro, so why did RME improve their FS version? Specsmanship?

 

[fpitas]

Of course I understand that jitter is inaudible in all decent modern electronics. I don't hear it in my RME Babyface Pro, so why did RME improve their FS version?

Probably because it helps move product to audiophiles. They love that kind of sh*t.

 

[mike7877]

Probably because it helps move product to audiophiles. They love that kind of sh*t.

I don't think that audiophiles are the primary consumers of portable digital audio interfaces lol. But yeah, I'd say they do it to say they made an improvement to something so that they're not selling the same product for 10 years.
I meant more in general why so often do people question improving something just because it's "good enough". If everyone just said "good enough" all the time the world wouldn't be nearly as advanced as it is now

 

[mike7877]

Like blaming the dog. And no matter how many times we explain the subject, it comes back.

I get it, it took one sentence tailored to my specific idea.
I was more having a [prolonged] brain fart now that I know where I went wrong lol

 

[fpitas]

I get it, it took one sentence tailored to my specific idea.
I was more having a brain fart now that I know where I went wrong lol

There are a lot of threads here with the same subject.