What does jitter sound like?

[cfmsp]

 

Bob said...

 

"It is self-evident from this thread, and its very great persistence, that those for whom jitter is not an issue are unwilling to simply leave it be and do something else. It has become mandatory for every on-topic comment to be immediately met with either derision, flippancy or, albeit well meant, yet another categorical rebuttal of its importance."

 

Spot on, Bob, and not only for this thread, but other threads where discussion is attempted about topics that some don't believe are important.

 

It's very amusing to read someone post 'lets put this thread to rest' when all one has to do is have the discipline to not read/reply AND not worry about what others are saying about a topic that is claimed to be unimportant (to those who can't stop reading/replying).

 

clay

 

 

 

 

 

 

 

 

[audioengr]

"Steve, when you list your specs at 2 pico seconds is that for intrinsic or accumulated jitter? Either way that is quite impressive."

 

This is the jitter of the oscillators only, not the system. The system is probably 10X that. Still too small for me to measure with my equipment.

 

Steve N.

Empirical Audio

 

[audioengr]

"So Steve, you were design lead on Pentium2, shame your hyperlinks to your many patents don't work!"

 

Yep, one of several design-team leads. It is a distributed effort, like all microprocessor designs, a cast of hundreds.

 

The links worked when I tried them. I'll check again...they still work fine.

 

Steve N.

 

[audioengr]

"I don't believe anyone else in the world has 'completely eliminated jitter'!"

 

Of course not, it's impossible.

 

Steve N.

 

[Roseval]

The links in the site works

The links in the Email send by CA don't

 

[DavidJPettifor]

I don't feel anyone has wasted their time here and certainly everyone is entitled to respond when they wish and how they wish as long as it's good natured and well intended.

 

From my understanding of what I've read in this thread, everybody is in agreement that jitter exists, that with a decent DAC it will be minimized to an insignificant level and therefore not be detrimental to the final audio presentation.

 

I've also been made aware that you don't need to spend buckets of money in order to achieve this. There have been some extremely useful recommendations with regards different DACs, in various price ranges (all sensible) for readers to take note of. I don't believe any of those products have been recommended by their own specific manufacturer.

 

All in all a thumbs up for this thread, its participants (both for and against) and CA to boot!

 

--

djp

 

[LAMF]

"Cambridge Audio stuff is superb..."

 

I concur with you and i have a question. Do you know by any chance if the engineers behind Cambridge Audio are the same guys that were in Audiolab?

 

 

[Al]

1 - Ashley James has not been banned from every UK forum - best make sure this drivel is true before you post it.

2 - Ash - you have a tendency to over-reaact to waht you think are criticisms and are continually on the defensive and the hard sell. there is a difference between promotion and jsut joining in, identifying yourself honestly (as you do), and providiong info on your products when asked. There are companies who do this really well on some of the UK forums, for example one where you have been posting about music copyright issues today.

3 - if someone has had their working methods called into question they have every right to quote their achiewvements without being called rude. jealousy is really ugly.

 

now, im sure you will all carry on forsaking civility and consistency in the hunt for a fight.

 

But leave my typos out of it.

 

* OK, disgusted is a very harsh word, especially for Ashley in my second point.

Certaionly you should all feel a little shamed and dissappointed tho.

 

So there.

 

[mpmct]

FWIW, Mr. Katz has my respect with what struck me as a fair

and measured comment on the 'GearSlutz' thread

( BTW, could they maybe have picked a more pleasant name for their site? ;-) )

 

"... But proving that what I hear is actually there and not imagined is another thing, as Ethan points out. We must be enlightened skeptics."

 

http://www.gearslutz.com/board/mastering-forum/351604-amount-jitter-makes-sound-worse-4.html

 

Obviously, from the multiple and sometimes near-simultaneous threads,

the debate will rage on. So be it. The bigger issue I think is to show that

measured differences are *audible*. If one gal or guy says he hears it, another doesn't,

the jury is still out. The hard work the folks at the Boston Audio Society did,

to level-match a set-up, and to have over 500 subjects submit to an ABX test

that meets scientific *standards* ( they are standards guys, Google will

verify ), that's the only thing we have to point to for verification I'm afraid.

 

And I'm all for making music sound better! If it does, I'm in with both feet,

and at a time in my life when I can afford it, lucky me. But I'm not buying

anything again on 'hear-say', not me. Been there, done that. Just MHO.

 

 

[Al]

we missunderstand eachother somewhere. i have not accused you of rudeness here, that was a separate point aimed at others calling someone else rude.

 

i think sometimes you cop it a bit too much sometimes (my hackles can rise easily too i confess) and this may lead to my impression that you can be defensive. one has to make allowanes for how things can come across on the net, too.

 

As long as Chris has no problem with you in respect of promotion, its none of my concern i guess, but i do see a little more of it than i think necassary sometimes.

 

Many thanks for responding much more calmly than i did the first time lol!

 

[mpmct]

 

Just MHO ... but after a few months of reading CA on a semi-regular basis ...

I have never found Ashley to be rude. Far from it.

I enjoy his commentary, which I have decided is

straight-forward and generally lacking in BS.

I could be wrong, but I doubt it. And yes, I know he is

a manufacturer, it's in his signature line!

 

 

 

 

 

 

[Ashley James]

Is designed by Doug Self who is extremely well regarded and has written numerous books on distortion mechanisms in amplifiers etc. These too are regarded as definitive, so it's not surprising that Cambridge Audio is embarrassing the more expensive competition. I don't think Doug had anything to do with Audiolab which IMO is not in the same league.

 

Al

 

I appreciate some of what you've said and am grateful, but am a little concerned about other points, for I don't believe I've been even slightly rude to anyone, on the defensive or that I'm promoting my products particularly, certainly not as much as others. In fact as I stated earlier, I've even discussed this with Chris to make sure that I don't overstep the mark.

 

Ash

 

[sastusbulbas]

Thumbs up to SteveN and PeterST,

 

With regard to the post by peter on Mon, 01/26/2009 - 05:17 — PeterSt (the big one), I think he mentions an important aspect of this debacle (fiasco), and one that in some ways addresses the forgotten point of this thread, the original question, which was the plain question "WHAT does jitter sound like".

 

The truth is without something to put in between that digital stream "before the Dac", to clean up the jitter so to speak, you may not know, people can suggest areas of performance which may or may not be attributed to jitter, but it will only be speculation. Most kit may only reduce narrow specific bands of "correlated" jitter which may be pointless, some kit is out there that will remove correlated jitter over a wider bandwidth.

I am sure there are many Dacs out there which deal with certain aspects of jitter performance, but most are only speculative, but we do not see any graphs or measurements given regarding their performance.

 

The difference and benefit may or may not be apparent, I am convinced it is system and disc dependent, I find well mastered discs and certain systems I have used benefited more with the Genesis Digital Lens than others, my own system is old, but it lets me hear changes up the chain between CD transports and digital sources, and I have quite a lot of equipment to play with.

 

The fact is that the claim of dacs being the be all and end all is nothing but speculation, and unless you can do as Peter has done, and output a signal with jitter and compare it to an identical out put with the jitter addressed you may not know if there is an audible difference worth bothering with.

In fact that subtlety may be why you chose one dac over another?

 

If you are happy with your digital replay leave it be, if on the other hand you find it fatiguing, or aspects of performance such as bass definition and pitch, system resolution, high frequency quality, or whatever being suspect, maybe you could be hearing detrimental effects due to jitter, or maybe you do need to address other issues?

My current cheapo computer project sounded clearly to my ears to perform poorly which had me question the quality of it's digital output, I was in the position to address that externally and therefore localise some of that detrimental performance as jitter, The computer sounds better with the Genesis, in much the same way as I find my better CD transports out performing my more mediocre components.

 

My goal is simple, I want superb digital replay via a PC for standard 16/44.4 material, with any Dac of my choice, therefore I want to address any issue of performance before the Dac. The dac is not an issue if one is happy with it's performance, or if is better with a CD transport in place of the PC, such a difference indicates the computer needs addressed.

For such a requirement, relying on some Dac to "make it better" is not acceptable, nor is it clever. There is a lot of great old and new kit out there, people should not have to limit choice due to ignorance. And I am sure for many it may be just as cost effective to address the issue of a good quality digital output at the source, than buy a new Dac which in many cases may not be "better" but just different sounding.

 

I want quality and decent specification, not any old mutton dressed as lamb. That is why I joined this forum, to see all the angles and address as many as possible for as little outlay as required. Audiophile Music Server for a Song, to me it stated the intent of this forum was getting the best from the computer, not making do, and relying on the Dac and faith. If the things that may cause subtle detrimental performance are to be belittled and deemed not worth bothering about, why not get into HiFi music servers for a song?

 

Cheers (with a smile)

Steve

 

[tfarney]

I think Ash is intelligent and well-spoken. Bloody handsome, too. Of course that's mostly because I agree with him.

 

Seriously, this is a tempest in a teapot. Ashley believes jitter has been addressed, in his own products and others. And as far as memory serves, he has been careful not to accuse those who persist in selling high-priced boxes to mitigate what he reasonably believes is inaudible of dishonesty (a show of restraint, given his opinion and profession) and has been equally careful not to promote his own products. He has, like all of us, promoted his own point of view and that is, of course, reflected in his products.

 

Duh.

 

All we have here is an age-old argument between trust your ears and trust the data. Personally, I don't see a conflict. I trust my own ears. When it comes to the ears of others, particularly those with something to sell, I fall back on the old adage: Trust, but verify. If I don't hear it, and what I don't hear is supported by the data, I come to the reasonable conclusion that my ears are telling me the truth. Others can hear what they like, come to whatever conclusions they like, and spend accordingly, and we should be able to discuss this and live peacefully. Well, except for the fellow who keeps dropping the troll turds on Ashley. He's being a bit of an ass.

 

It will be discussed, however. Every time a newbie comes in here asking a question and is recommended an expensive DAC or transport or something else that I believe is, at the very least, the wrong place to spend until everything else has been well-spent upon, I'll speak that point of view, and if that point of view, and the data the data that backs it up, makes someone feel like I have accused them of psychological bias or questioned their professional expertise, so be it.

 

There's really not much point in hanging around forums to do anything less.

 

Tim

 

 

[DavidJPettifor]

God Tim, you're so damn eloquent!

 

--

djp

 

[tfarney]

"to me it stated the intent of this forum was getting the best from the computer, not making do, and relying on the Dac and faith..."

 

But those of us over here on this side of the debate are not "making do" and not relying on the DAC and faith. We're relying on theory, data and belief that says if you have a bit-perfect data path prior to the DAC, you ARE getting the best from the computer, that the DAC is the source, that the conversion and the subsequent analog signal chain is the what deserves our attention. And, apologies in advance, we're pretty sure that believing otherwise is the stuff of "faith."

 

I'm beginning to wonder if this debate is religious.

 

Tim

 

PS: Thanks David. It's my day off. Too much time on my hands.

 

[Al]

There you go, eloquently missing the point in order to show us all how brave and articulate you are; it wasnt you i accused of questioning someone's proffessionalism, as you know very well.

 

Still, well done on the grand-standing. Afterall, thats what its all about...

 

...oh, hang on...

 

 

 

[jimim]

Question if anyone knows. Got into this topic on another forum. Does anyone know what would have less jitter transmission over HDMI. . .LPCM or Bitstreamed audio?

 

Simple question. . .

 

jimi

 

[cfmsp]

 

 

We have a winner!

 

"I'm beginning to wonder if this debate is religious."

- Tim

 

 

 

clay

 

 

[audioengr]

Here are some interesting opinions from other industry experts:

 

http://www.positive-feedback.com/Issue41/ca_intro.htm

 

You will notice that jitter is #1 or high on the list of almost all of them.

 

Steve N.

Empirical Audio

 

[tfarney]

Yes. I also couldn't help but notice that they are almost all high-end audiophile DAC manufacturers. Not that their views aren't pertinent to the discussion, but they can't really be seen as objective either. I suspect if we had the views of the engineers who designed the Apogee Duet, for example -- a fully functional professional field recording interface including a DAC, a ADC and a pretty damn good headphone amp, all for

[cfmsp]

 

steve, thanks for posting this.

 

...at last, lots of different religious sermons...it was starting to get a bit boring, given the dearth of 'religious' choices here.

 

 

clay

 

 

 

[tfarney]

"Oh Tim, Tim, Tim,

 

There you go, eloquently missing the point in order to show us all how brave and articulate you are; it wasnt you i accused of questioning someone's proffessionalism, as you know very well.

 

Still, well done on the grand-standing. Afterall, thats what its all about...

 

...oh, hang on.."

 

Al, relax. I didn't think you were accusing me of anything and nothing in my post was about or addressed to you. Oh, and I hardly think it is brave to express my opinion on an internet forum. Rather ordinary, actually.

 

Tim

 

[mpmct]

Doing an after-hours shoot out with my Bel Canto DAC3 versus

a Cambridge Audio DacMagic, fed through a US mod'ed Rotel RC-06 pre-amp

with very low THD, yadda yadda yadda. Listening for jitter. Killin' me.

 

I'm also making my passive loudspeaker ordeal face up to two active systems.

There's where it gets interesting. ( Yes, there are a lot of wires here. )

Ladies and gentlemen: puhleeeze ... think active. I beg you.

Jitter is so, like, insignificant, so small and dull, IMO. ;-)

I suspect your eyes will light up and you might wet your pants

in listening to a well done active system.

Keyword: Detail! I would write 'nuance' but that's so like ... Stereophile. ;-)

 

[drdigital]

Quote:Here are some interesting opinions from other industry experts:

 

http://www.positive-feedback.com/Issue41/ca_intro.htm

 

You will notice that jitter is #1 or high on the list of almost all of them.

 

Steve N.

Empirical Audio End Quote

 

Steve; It is hardly suprising that hi-enders spout on about jitter, it became an industry obsession years ago so any hi-end manufacturer would be foolish not to jump onto the 'Jitter-wagon' !!!

 

In one of your posts you completely trashed the pro-audio industry as DAC makers but you completely miss the point that it is the self same pro-audio industry that supplies most of the ADCs used to make the recording in the first place.

 

As any digital audio engineer knows; Jitter at the ADC causes the same problems as at the DAC!!!