Can a frequency Divider cause Jitter?

[Jocko Homo]

First off, Lars, ol' buddy......ol' pal.....
I have nothing personal against you, or your company.

I wish no ill to either you, or your company.

(Judging by the complaints that find their way to my inbox, you do enough of that yourself already.)

I do not wish to run you off.

But, having said that......

A lot of us are tired about the way you (ab)use this forum.

You constantly seem to do one of two things:

1.) Talk about your products, and refer us to your website in darn near every other post. In all fairness, you seem to do less of this than you used to. A positive step.

2.) Using the forum for "market research".

To those of us who didn't just fall off the back of a turnip truck, every time you start one of these threads it looks like:

"What do you guys think of this? If I made one, would you buy it? If not, what do I need to do so that you will?"

Here we have an example of the latter.

Now.........you say that you want to discuss what interests you. Fine, we all want to do that. But when it reeks of making money along with it, you invoke the wrath of many good people.

(For the record, there are others who do this. And yes, I give them grief. Some of them get the message.)

But anyway...........seeing as how you are the guy who stated.....what was it 2 weeks ago?......to "not believe everything that you read on these forums"

So why do you continue to ask?

Well, seems obvious to lots of us: market research.

But why in the world would you even think of doing that in the first place?

If you want to have products to sell, that is fine. But why ask potential customers what they want under the guise of DIY?

Your job, as a businessman, is to tell them what they want, and why they want it. Not to go scrounging around for ideas from your potential customers. You are already supposed to have the ideas. They are supposed to look to you for solutions, not the other way around.

But you do, and what is the result:

You look like a fool. You seem to have no more of an idea what causes jitter, how it is created, or how to reduce/eliminate it with your line of questioning. Maybe you actually do know these things, but you give the impression that you know as much as the guys you are trying to sell stuff to.

(While I am at it........someone tried to implement your idea of installing the clock in the D/A box, and pumping it back to the transport. Too bad there were flaws in your scheme.)

So, as much as you probably think that I am trying to wreck your business, I am not. You seem to do that without my "assistance".

I just wish that you would participate as one of the guys, instead of as some guy who seems like he has one hand behind his back, holding something that he wants to suddenly shove in our face, going "Taa-da! Lookee here what I got for you! A gold-plated turd! You wanna buy it?"

While I am at it.......I know of no one who has a problem with guys that have a commercial interest being here. A lot of guys do have commercial interests. With very few exceptions, they are welcomed, and accepted as part of the gang. I see no need to mention them (why should I advertise for them, anyway?), but maybe you should take a cue from them, Lars.

But as to the jitter question:

No, I would not do it that way. In all honesty, I have not poked my nose into anything newer than a CD-80, which were made back in '89, maybe '90, too. So, maybe if I did, I would have a solution to this seeming problem.

Whether I would share it with P-A.......well, that is another story. [joke]

Jocko.

[Guido Tent]

Originally posted by guido


Elso,

Would the transfering of the I2S signals not introduce some jitter over the interface (buffers,cabling), where clockfeed-feedback would not ? This when not using async overclocking, i guess.

Do i know how to post icons. I'll when i hit submit...

GuidoB (mind you not Tent)

Here's Guido T.....

Yes, transfering signals has risks too (induced jitter)

Reclocking I2S just before they enter the DACs is minimum requirement. Ofcourse you need a super clean clock (and power supplie and decent lauoyout and and and) just THERE

Having a free running clock there is non plus ultra, one step below that is a decent PLL / VCXO

The free running clock can be fed back (not my preference) or be part of PLL with VCXO in drive (more electronics, less risk and easier to implement). Linn did that (coneptually, the implementation was not optimised) in the Karik / Numerik.

I have the options in my XO DAC board

Reading our web page and some spare time and you can do it yourself.....

Ciao

[Jocko Homo]

"Reading our web page and some spare time and you can do it yourself....."

See.....a good example of a guy who sells stuff telling someone:

"Here....you can do it this way......I'll show you how if you need help......but you do not need me to do it for you.....do it yourself!"

(Actually I was thinking of guys who sell amp kits as examples of good DIY guys with side interests.)

But as for I2S transfer.......

It should have less of a jitter problem, as you do not have to recover the clock from a serial data stream. Reflections here have a significant impact on jitter. Typical jitter numbers on a SPDIF setup can easily exceed 1 nSec.

A good clock scheme should have numbers <10 pSec. On a I2S setup, I would imagine that you could keep the jitter in the tens of pSec range, ceratinly under 100 pSec.

Maybe not.......if noisy supplies, and chips with too much stuff going on inside are used.

Jocko

[Lars Clausen]

Jocko: Thankyou for your comment, which i sense is well meant.

In some cases i must admit you are right.

Even if i wouldn't call it 'Market Research', still i am trying to listen to the 'word on the street', to get a sense of where DIY'ers are right now.

I don't feel it's wrong to listen to customers opinions.
In other cases i have posted a thread with some ideas or fun projects, also with no connection to my company's products.
Like the ULCA thread. In case of the Low Budget DVD player thread, you can argue that i used one of my own products to upgrade it, but i did not show pictures of it, and i never implied that the upgrade could not be performed with any other clock. But since i used a clock for the upgrade, i figured just as well use one of my own....

In case of this particular thread, it has no relations to any of my present or future products, as i would never build a clock with a frequency divider, as i stated earlier, it is strongly against my own persuation.

Sometimes the tread bends, and entirely other subjects come up, where i feel compelled to answer questions or comments on my products. Like this thread, only a couple of replies were about the subject: 'can a frequency divider cause jitter'. The rest is mainly politics and entirely other stuff. It's ok, but i constantly try to take the thread back on tracks... What i mean is: i don't try to turn the thread towards any of my products, or make advertisement. But i think it's fun to discuss Audio Technology, because this is my interest (as well as my job ... yes). And i believe that discussing Audio Technology, is what DIYAUDIO.COM is all about.

In case of posting links to my web site, i think you can see that i only used our server to upload picture files, nothing else. No links or other relations exist between my company and the projects i have posted here. But if it will make you happy Jocko i will in the future use another server with an URL unknown to the audio society. No problem

I agree with you, there is nothing wrong with people being related to the audio industry commercially, or in some cases even making advertisement for their product. As long as they keep it out in the open. There are tons of examples of hidden advertisement on DIYAUDIO.COM, you can see it all the time.

This is why i have suggested that everybody publish their commercial interest, so everybody can see it.

I thankyou very much for your great confidence in me as the big business man Not quite accurate (even if i wish it was so) I am little more than a DIY'er like every one of you, just that i turned it into a job. As could any one of you guys if you want to.
We are now 4 employees in L C Audio Tech, i wouldn't call it big business.
But we are pretty much all driven by interest in DIY audio, and not - as some may think - the urge to make money.
The annual accoutings would support this claim.
Luckily our mother company is also more interested in the performance of products, than in the monthly budget sheet, so we have no problem there ..

OK Jocko, this was also a long reply, i take your point, and i will try to act accordingly less probing in the future, and i hope that from now on we can all be friends, and talk about our common interest, Audio Technology. After all i think we all agree that's the fun part.

All the best from LC

[Jocko Homo]

Maybe you should consider not starting these kinds of threads. Let the guys who are wrestling with this stuff do it. Then you can add: "Yeah, I tried it......worked great.....", without referencing where/when you did it. Likewise with: "No, it stinks. Did it once, the product bombed. Never again." Or, "Hmmm.....I dunno.....have to look into it someday. I'll report back when I do."

I think that if you participate long enough, you will get a grasp of what the average DIYer is all about. Quiet observation should be sufficient "market research".

Hey, I get lots of requests: "Jocko.......those surplus boards that you offered up once.......do you have any more? Ever think of making any?"

Answer to both is always "no". Surplus boards are just that: when gone, they are gone. In order to make them affordable to the average DIYer, I would have to make lots of them to get the price down. Sorry, guys, but I can not tie up what little operating capital that I have left, making a stack of boards, that will sit for years.

So, Lars, you can not always expect the guys here to have an interest that will be in your interest . Unless you want to be a "boutique" supplier, I suggest that you will just have to forge onward, and make products that you have strong faith in, rather than try to read a fickle market. Many of us have tried that, and learned the hard way.

Jocko

[Lars Clausen]

Jocko: That's real good advice!

Thanks!

I will take it of course!

[TNT]

Sorry Lars to get You into this debate but I actually agree of some of the points forwarded but was not ready to state them myself. I feel to new to the forum to hve expressed them.

I'll give Yoy credit for Your open and humble attitude in the matter and hope we can "live together" in the future, the newbies (me), the proffesionals and all other wery competent people frequenting this forum !

Personally I would like seeing a statement under the posters avatar regarding connection to proffesional bussines.

Who Mr. Pass is we already know ;-)

/BR

[Cobra2]

I have been wondering about this too....

Another use would be making a UNIVERSAL clock, with all frequenzy options incorporated, by dividing / adding, and thereby maybe offer a better X-tal (and lower price, since one freq. can be purchased in larger lots).
Then you also have solved the Trans/Dac-diferent freq. problem.

How's that for marked research(brainstorm)?

Arne K

[rfbrw]

This universal clock sounds like a solution in search of a problem given that a reasonable crystal oscillator canned or otherwise does not cost a fortune.
The basis of the original question is flawed. One might as well ask " The round tyre. Does it cause rolling resistance?" The answer, as with the original question is yes it can but do you have a better solution.

ray.