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Old 29th March 2013, 05:36 AM   #37511
1audio is offline 1audio  United States
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Jitter shows as symmetrical sidebands around the central tone.
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Old 29th March 2013, 09:00 AM   #37512
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Quote:
Originally Posted by 1audio View Post
Either a modulation analyzer, a real phase noise analyzer or a tweaked FM tuner are the solutions for looking at Jitter on the clocks.
Demian,
Although jitter for the serious professionals seems not to be a single number topic http://www.anritsu.com/en-GB/Promoti...sis_EF3100.pdf
I am interested in a diy way of estimating jitter “quantity” in audio equipment (calibrating in standard terms is not of my concern).

I think the FM tuner tweaking may be an option for me. My scope is a 20MHz analogue unit and my soundcard goes to 21KHz.
Is it possible to write the essential outline of the idea?

George

PS Some useful side notes on jitter.
Jon_Risch's Web Site

And some relevant thoughts to this thread's concerns
Ed Meitner: Audio Maverick | Stereophile.com
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Last edited by gpapag; 29th March 2013 at 09:07 AM.
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Old 29th March 2013, 11:58 AM   #37513
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it reads like an engineer listing out scare tactics carefully worded to sell a product to neurotic audiophiles... he knows his market
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Old 29th March 2013, 12:23 PM   #37514
gpapag is offline gpapag  Greece
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Meitner talks over a few audio issues there.
But on jitter, he tries to confine the angle within the audio band.
When he is trying to focus there, quantifying measurement results and looking for any correlation with audible effects, I think he does not get very neurotic, let alone audiophilic.

George
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Last edited by gpapag; 29th March 2013 at 12:25 PM.
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Old 29th March 2013, 01:31 PM   #37515
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Of course, gpapag. Both Ed Meitner and Jon Risch are audio engineers who go out of their way to look into even better audio design methods, just like me.
It is only the people outside the field of quality audio design who would think they are marketing something to a gullible public. You know, the same thing that I am accused of.
This is just general 'bad-mouthing' somebody who actually contributes to improving audio quality.
Now I could tell you about these guys, what they have done, and when I interacted with both of them, but THEN I would be accused of 'name dropping' or some-such, so I won't go any further.
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Old 29th March 2013, 01:42 PM   #37516
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Quote:
Originally Posted by qusp View Post
you dont really feel that an opamp is always the best choice do you?
No not at all, although I believe that within the area where multiple opamp types are available (+/-15V, high gain, sufficient BW, not insane loading) I believe there's no advantage to be gained by going discrete.
But there are sure areas where discrete would be better simply because the equivalent IC doesn't exist.

jan
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Old 29th March 2013, 01:46 PM   #37517
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Quote:
Originally Posted by Kindhornman View Post
On the Virtins Technology software package mentioned earlier they are also showing the separate external oscilloscope modules to the right of the page. Is this only a capture card application or is there something I am missing here with those? How do those interface with the software and what do they add to the picture? Humor me as I am trying to understand all of what is being said here...
The scope module is one of the sevaral 'test instruments' available, and you can pick from a menu what you need. If you buy the pro version as Pavel has done ($200) the scope module is included.
The Virtins setup lets you chose separately the DAC and the ADC device from whatever is connected to your PC, so I guess that you could have different soundcards or DAQ devices (Virtins also manufacturs DAQ devices).

jan
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Old 29th March 2013, 02:09 PM   #37518
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Quote:
Originally Posted by john curl View Post
Stay consistent, please.
You know Mr Curl, I've been trespassing this thread from week one, mentioned a zillion times that you should be treated with some respect, plus that the BT is the prettiest preamp ever imo.

I can't recall ever stating that the CTC was overpriced, think I just gave an example of a German preamplifier with a retail that's way over the top and severely lacking a sense of reality and taste.

What I find intriguing is the number of +$10k preamplifiers over the last ~decade, which are technically up to speed, but with very poor external build quality.
The latest ML No52 for example, beautiful boards, but industrial modular caseworks that I personally find shocking.
To me it looks like it rolled off an assembly line in Asia, at $25k it shouldn't.
Different strokes for different folks.

The message to Frank was that for Vette or Ferrari it's become less of an issue whether it's pushrods & plastic leaf spring rear suspension, or dual overhead camshafts & multilink.
It's aluminum monocoque and carbon all the way, in both cases.

The real question Frank should have asked is whether sound quality of the BT is inferior to contemporary opamp based preamps, not the other way round.
He could easily find out for himself by breadboarding a transconductance stage à la Mr Uskokovic, and ordering a 797 pair.
If he favors the second option, fine. If it's the first, then Frank is in trouble.
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Old 29th March 2013, 02:47 PM   #37519
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George,

The Meitner piece is scary good. He mentions a number of issues I consider secret sauce in my systems.

Demian,

I got another denizen of this loony bin to solve my jitter issue. But where did you learn the trick of using an FM detector? (I need to have real numbers to present rather than I tweak it a bit.)

ES
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Old 29th March 2013, 02:53 PM   #37520
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Quote:
Originally Posted by gpapag View Post
Meitner talks over a few audio issues there.
But on jitter, he tries to confine the angle within the audio band.
When he is trying to focus there, quantifying measurement results and looking for any correlation with audible effects, I think he does not get very neurotic, let alone audiophilic.

George
not in the typical sense, hes obviously done his homework and paid his dues, I said nothing at all about his skill or knowledge in the area despite the words John likes to put in my mouth, but I do believe he is rather predictably playing up some audio fashion issues wrt jitter and the text is rather buzzword laden and complete with subjective analysis. He is playing up the difficulties and expense to design things properly to avoid the jitter etc. when it can be eliminated completely with a module bought here on the forum for $250 + 2 clocks and works with i2s or spdif sources alike, with any dac with i2s input, producing the same very high quality regardless of the source. he speaks of cutting edge things that may be possible in the future that are pretty much already being done here by hobbiests without the polish and aircraft grade alloy chassis.

sure he IS selling a product, so its not surprising and I cant blame him, but its also pretty transparent. just a few carefully chosen words to encourage that great motivator, fear... in potential customers. relying on his customers neurosis to do the work, while appearing (and actually being) quite rational

@ John
I love how you are putting words in my mouth, so funny and just a bit juvenile. part of the victim act of course, poor misunderstood John...

Last edited by qusp; 29th March 2013 at 03:03 PM.
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