AVS/AIX High-Resolution Audio Test: Take 2 - Page 27 - AVS Forum | Home Theater Discussions And Reviews
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post #781 of 940 Old 12-23-2014, 01:05 PM
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"THIS time we'll get it right...promise!"

paging PT Barnum.
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post #782 of 940 Old 12-23-2014, 01:08 PM
 
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Is there any website (audio forum) on the Internet where we can learn about all that hi-res audio stuff?
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post #783 of 940 Old 12-23-2014, 03:23 PM
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Originally Posted by NorthSky View Post
Is there any website (audio forum) on the Internet where we can learn about all that hi-res audio stuff?
The posts can at times be somewhat technical, but a forum where you will find explanations that refute the claims of alleged audible superiority of hi-res audio is: www.hydrogenaud.io
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post #784 of 940 Old 12-23-2014, 08:29 PM
 
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Originally Posted by MLXXX View Post
The posts can at times be somewhat technical, but a forum where you will find explanations that refute the claims of alleged audible superiority of hi-res audio is: www.hydrogenaud.io
Thank you sir. ...I am a member and read some already.

Merry Christmas.
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post #785 of 940 Old 12-23-2014, 09:21 PM
 
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Originally Posted by MLXXX View Post
The posts can at times be somewhat technical, but a forum where you will find explanations that refute the claims of alleged audible superiority of hi-res audio is: www.hydrogenaud.ioo
Well, you find more than that there. Take a look at this post I wrote which was deleted for violating their forum Terms of Service 8: http://www.hydrogenaud.io/forums/ind...owtopic=107730

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Originally Posted by amirm on HA
???? Filters are spec'ed with respect to amount of attenuation they provide. The attenuation is relative to the input amplitude. To borrow a phrase from our British friends, showing measurements like I did is "bog standard" practice in characterizing DAC PLL jitter. Here is one of many such references:



As you see they too have the 0 db reference and filtered amount as negative numbers. And also show the peaking that results in amplification of jitter near corner frequencies.

It is quite surprising that you think there should be absolute numbers.

To expand, our interest is in the 20 Hz to 20 Khz audible spectrum. To the extent a device shows no attenuation of jitter in that band, it means its PLL only filters ultrasonic and higher frequency jitter which is good for accurate data extraction but not from audibility point of view.
Didn't think I would ever see an audio forum outlaw discussion of audio technology until I set foot there. I left faster than they could close the door behind me.

Happy holidays everyone.
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post #786 of 940 Old 12-23-2014, 09:23 PM
 
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Amir, you are still alive!

Merry Christmas, and to your all family.

P.S. They have a Recycle Bin section!?! ...Cool, that, I did not know.
* Do you guys have one of those over @ WBF? ...About a recycle bin for "lost" avatars?

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post #787 of 940 Old 12-23-2014, 10:07 PM
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Originally Posted by amirm View Post
Well, you find more than that there. Take a look at this post I wrote which was deleted for violating their forum Terms of Service 8: http://www.hydrogenaud.io/forums/ind...owtopic=107730



Didn't think I would ever see an audio forum outlaw discussion of audio technology until I set foot there. I left faster than they could close the door behind me.

Happy holidays everyone.
That post is dated Dec 10.. You joined on Nov 11. You posted >10 times a day while there.

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Yeah, you really hightailed it out of there.
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post #788 of 940 Old 12-23-2014, 10:08 PM
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Originally Posted by amirm View Post
Buying a safer car with more safety equipment and wearing your seatbelt won't guarantee that you won't get hurt in an accident either. But they sure as heck make you safer driving. By the same token, high resolution distribution opens a path for better mastered releases to the consumer. It absolutely positively does that. It need not guarantee anything to have huge value.

But go ahead and text and drive in an unsafe car because doing otherwise doesn't guarantee that you won't get killed in a car accident....
I've not seen an analogy this inept in some time.

You OK?
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post #789 of 940 Old 12-23-2014, 10:55 PM
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Any of you ever go to a ball game? Maybe one where there's been a recent history of animosity between the two teams. You're a fan but not a die hard one who intimately knows the stories, plots, subplots, and whatnot that make the game what it is.

You see the umpire talk to both managers brfore the start of the game but you can't hear what's being said. Second inning comes around and the pitcher for your team is now facing the opponent's clean up batter. First pitch is tight and inside, above the letters. The ump says something to the pitcher. Second pitch is outside but the third, while belt high is so inside it nails the batter in the back. Umpire tosses the pitcher. Pitcher freaks and his manager comes out to argue with the ump and he's pissed. Ump tosses him too.

And you're there thinking, so what? Batter gets first base. Then later you go home and wind up catching ESPN where they're talking about the game. And then you catch the stories and back stories. You find out this pitcher has a history of retaliation and it's not the first time he's been thrown out. You find out those two teams have been playing beanball off and on the last few times they met. Maybe TMZ has a juicy story how that batter was photographed with the pitcher's GF coming out of a hotel with him.

Then you realize just thinking the pitcher was unfairly targeted might be a superficial analysis. Maybe there's more to the story.

"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House
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post #790 of 940 Old 12-24-2014, 05:14 AM
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Originally Posted by amirm View Post
Didn't think I would ever see an audio forum outlaw discussion of audio technology until I set foot there. I left faster than they could close the door behind me.
In my opinion there was no outlawing of discussion of audio technology as such.

I think your particular post was removed from the thread either for want of relevance (your reference to very low measured jitter levels in a thread aimed at identifing a jitter level that made an audible difference) or for an apparent a breach of TOS 8 (an apparent implication that a "superbly" low measured jitter level makes an audible difference, but without your offering proof that such a measured difference is audible).

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Happy holidays everyone.
Yes, best wishes of the season to everyone.
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post #791 of 940 Old 12-24-2014, 07:01 AM
 
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Amir, you are still alive!

Merry Christmas, and to your all family.
I am indeed. Warmest Merry Christmas to you also Bob.

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P.S. They have a Recycle Bin section!?! ...Cool, that, I did not know.
* Do you guys have one of those over @ WBF? ...About a recycle bin for "lost" avatars?
It is an interesting feature. Not sure if it is good or bad or whether all moderated posts go there or not.
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post #792 of 940 Old 12-24-2014, 07:36 AM
 
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In my opinion there was no outlawing of discussion of audio technology as such.
Oh there is. The place reminds of professional wrestling where the referees wears the cloths but of course is part of the "story." There is no real sport there but entertainment and a plot to follow.

Likewise they have created a forum with the stated goal of one opinion in audio and anything deviating from it is treated harshly. It is shame as they have some excellent members there but their contributions is lost in the sea of unprofessional posts left in there just because it supports their point of view in audio.

Nothing wrong with that of course. It is their forum and they get to run it as they see fit. It just isn't for me and is unique in the way it pushes one stance in audio to extreme. One can't possibly get to the full truth on any topic though if the forum engine of operation works against one point of view in audio and strongly so. So I responded when you said with such certainty that some kind of truth was being told about high resolution audio there. By definition it cannot be unless you think professional wrestling is about a fair fight .

Quote:
I think your particular post was removed from the thread either for want of relevance (your reference to very low measured jitter levels in a thread aimed at identifing a jitter level that made an audible difference) or for an apparent a breach of TOS 8 (an apparent implication that a "superbly" low measured jitter level makes an audible difference, but without your offering proof that such a measured difference is audible).
Sorry no. You are rewriting history even though you were there and the thread is pretty short so one clearly see what happened.

We got into measurements because you made an off-topic remark as such:

Quote:
Originally Posted by MLXXX on HA
I note as a general comment that there is always the possibility of reducing jitter anyway in a playback device by use of a small buffer and a steady clock with a relatively slow time constant for fine adjustments to its clock rate, if there is any doubt about the short term timing stability of a stream of incoming digital audio. What extent of buffering is commonly in use I have no idea.
Your description of how the system works was incorrect and aimed at dismissing the issue as existing at all. What you said had nothing to do with listening tests as presented and hence should have been removed with the sanction placed at your feet. But it was not because what you said, yet another distortion not mattering, serves the forum's opinion of audio.

Then Arny, not me, post a bunch of measurements using my data no less, with multiple references to me to which I responded. I showed how in real measurements of AVRs, little to no filtering is performed. And indeed, jitter is actually magnified. Arny challenged that response and when I answered showing how that exactly happens, my post was deleted that I post above.

Furthermore, I tried to stay on topic by posting my listening test that I was challenged to re-run by Arny. He claimed that I must have cheated somehow and demanded that I re-run his jitter tests with the new foobar ABX plug-in that computes cryptographic hashes of the files and log files. I did so in the thread he asked about it and tried to put a copy here where it belonged. But that post kept getting deleted too:

Quote:
Originally Posted by amirm on HA
I ran the tests again just now and documented a specific procedure for passing the tests legitimately: http://www.hydrogenaud.io/forums/index.php...st&p=884128

Edit: Here is the new link to my results in the recycle bin: http://www.hydrogenaud.io/forums/ind...owtopic=107718
The violation was "Off-topic." Here we have your post and Arny's that are fully of off-topic discussion of jitter and how it works, see http://www.hydrogenaud.io/forums/ind...dpost&p=884045, left in there yet me posting listening results is off-topic?

Here are other technical posts they deleted: http://www.hydrogenaud.io/forums/ind...owtopic=107690

The violation was this: 2. All members, at the staff's discretion, must converse in an acceptable fashion to be allowed the privilege of continued participation.

I think it was that post that caused me to received a 3-day ban and got the message to leave finally . As you see there, there is nothing personal or unprofessional in that post. It is a pure discussion of technology and answering repeated and unprofessional challenges for me to do so.

I like to again state that I have no issue whatsoever with how they run the forum. It is their party and they get to set the rules and if you don't like it, you need to leave. I am thankful for having them tolerate me as long as they did. I am grateful for interactions with a few knowledgeable members there and opportunity to state my peace.

Just don't tell us here, that somehow the truth about audio is and high resolution formats is told there. It is not where a balanced discussion is not allowed.
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post #793 of 940 Old 12-24-2014, 10:03 AM
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It is their party and they get to set the rules and if you don't like it, you need to leave. I am thankful for having them tolerate me as long as they did.
IMHO, there's no need to bring "the party" to AVS.
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post #794 of 940 Old 12-24-2014, 10:44 AM
 
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I had that same exact feeling when I was five-years old.

__________

* Merry Christmas Ratman.

...And may the heart of all men, women and children on Earth be filled with true Love and true Peace.
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post #795 of 940 Old 12-24-2014, 10:50 AM
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IMHO, there's no need to bring "the party" to AVS.
Depends what you're bringing to the party.

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post #796 of 940 Old 12-24-2014, 11:48 AM
 
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In other news Google, YouTube and XBox are streaming ‘The Interview’ on Christmas Eve"
http://fortune.com/2014/12/24/google...the-interview/

Should be avail in Dolby 5.1.

I'll wait till it comes on Netflix or Amazon Prime Instant myself .

Merry Christmas to all !



@Chu Gai , ^^^^^^ I'll have one of those for Christmas

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post #797 of 940 Old 12-24-2014, 02:57 PM
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In other news Google, YouTube and XBox are streaming ‘The Interview’ on Christmas Eve"
http://fortune.com/2014/12/24/google...the-interview/

Should be avail in Dolby 5.1.

I'll wait till it comes on Netflix or Amazon Prime Instant myself .

Merry Christmas to all !
If North Korea tricks us all into wasting 2 hrs watching this (by all accounts) real dog of a movie, then *the terrorists have won*.
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post #798 of 940 Old 12-24-2014, 03:52 PM
 
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If North Korea tricks us all into wasting 2 hrs watching this (by all accounts) real dog of a movie, then *the terrorists have won*.
From what I've read it's not anything I would go out of my way to watch lot's of better stuff ahead of it on my Netflix watch list even they get it. It probably would have been a dud revenue wise no matter what.
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post #799 of 940 Old 12-24-2014, 04:12 PM
 
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Depends what you're bringing to the party.

Right on!
That's what the audio community of the entire planet is all about. So bring them on aplenty, and if they don't bring them with them, ban them all!

Life is short, best to enjoy it, and best to put on your best colors. ...No crap like old defective CDs, just brand new hi-res music downloads.
...Freedom for all or go home. ...Live and let live. ...R.E.S.P.E.C.T.

Ok, are those AVS/AIX audio tests accurate?

* Merry Christmas Frank.
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post #800 of 940 Old 12-24-2014, 06:02 PM
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Quote:
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We got into measurements because you made an off-topic remark as such:
Quote:
Originally Posted by MLXXX on HA
I note as a general comment that there is always the possibility of reducing jitter anyway in a playback device by use of a small buffer and a steady clock with a relatively slow time constant for fine adjustments to its clock rate, if there is any doubt about the short term timing stability of a stream of incoming digital audio. What extent of buffering is commonly in use I have no idea.
Your description of how the system works was incorrect and aimed at dismissing the issue as existing at all.
I don't think the statement of mine you have quoted is incorrect in a material way. I stand by my statement that if there is doubt about the short term stability of a stream of incoming digital audio that doubt can be addressed by buffering.


You chose to present some measurements of jitter for certain devices. However unless you were contending that any of the jitter levels shown in the graphs made an audible difference, the relevance was, in my opinion, tenuous. [It is Christmas Day where I am and I will probably respond in more detail later. Cheers]
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post #801 of 940 Old 12-24-2014, 06:25 PM
 
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I don't think the statement of mine you have quoted is incorrect in a material way. I stand by my statement that if there is doubt about the short term stability of a stream of incoming digital audio that doubt can be addressed by buffering.
Nope. That is simply wrong. Buffering is before the DAC. The clock for the DAC can still vary both because it has to track the input (remember, the systems are synchronous and the DAC is a slave, not master) and because system noise can couple into the DAC clock independent of what the input is doing, to induce jitter. The Anthem measurement shows this clearly:



These measurements were made seconds apart. Clearly the buffer did not pop in and out of the circuit randomly. It is always there but its job is to simply store samples temporarily. It cannot and will not by itself perform any jitter reduction.

Your assumption is a common one but it simply is wrong. The system does not work that way.

Quote:
You chose to present some measurements of jitter for certain devices. However unless you were contending that any of the jitter levels shown in the graphs made an audible difference, the relevance was, in my opinion, tenuous.
Which is a separate point from saying the problem vanishes because there is a buffer.

The reason it is important to address the theory is because if the theory can prove inaudibility we are done. We don't need a listening test. This was the crux of your statement which is the implication that buffering removes jitter and hence, why worry about listening test. That is proper logic, but wrong assumption. Buffering doesn't remove jitter so we can't make a statement about that in the context of audibility.

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[It is Christmas Day where I am and I will probably respond in more detail later. Cheers]
Ah, we have a few more hours to go. Hope Santa is good to you .
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post #802 of 940 Old 12-25-2014, 01:53 PM
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Oh there is. The place reminds of professional wrestling where the referees wears the cloths but of course is part of the "story." There is no real sport there but entertainment and a plot to follow.

...

By definition it cannot be unless you think professional wrestling is about a fair fight .
And this is what happens when there is inadequate headroom in the squared circle:

http://www.liveleak.com/view?i=837_1418011555

I'll be back later...


System links::: 1.5RQ > digits from all sources > 1177a > OpenDRC-DI with AcourateDRC > DEQ2496 > DAC2 > KCT > FPB 350mcx > reQuest + Cheezewoofer Wattless Deluxe > Sweetspot
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post #803 of 940 Old 12-25-2014, 05:12 PM
 
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That was funny!
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post #804 of 940 Old 12-25-2014, 06:16 PM
 
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Darn funny!
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post #805 of 940 Old 12-28-2014, 05:00 AM
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Amirm,
I have reread the Hydrogenaudio thread Jitter Listening test files, Jitter Listening test files available, including your contributions appearing in the thread as posts 10, 14, 20, and 24.
I would draw your attention to your post 10 ( http://www.hydrogenaud.io/forums/ind...dpost&p=884051 ) in which you refer to customer expectations that can make it difficult to attain low jitter figures:
Quote:
Originally Posted by amirm at HA
Buffering gets used in every device out there. The problem with slow adjustment is the tracking range is very wide. A receiver needs to lock onto sampling rates from 32 Khz to 192 Khz. If it goes too slow, when you switch sources, you will have to wait many seconds for it to find and lock onto the incoming sample rate. Customers will not accept input switching delays of more than 1 or 2 seconds whereas they are oblivious to jitter as a problem so fast switching wins.
However you then go on to state:
"There are solutions to this but it requires design skills, and a few dollars worth of parts..."


I would agree with you. That is what I meant when I said earlier in this thread: "I stand by my statement that if there is doubt about the short term stability of a stream of incoming digital audio that doubt can be addressed by buffering."


I did not mean to imply that all attempts to address jitter through buffering are successful in terms of measured reduction in jitter. If they are unsuccessful then that is poor engineering if the purpose of the buffering is to reduce the jitter. If the purpose of the buffering is merely to stop overruns and underruns in the processing of the received datastream then the buffering has achieved its purpose.


I note -- and this I suspect is not appreciated by some people -- that even high levels of measured jitter should not be taken to mean loss of data. Typically, once lock is achieved in a domestic setup between CD player and AVR or Blu-ray player and AVR, not a single bit of data is lost in the transmission. The question of jitter is only a question of the steadiness of the clocking of the received data stream from the buffer.


It is true that over the medium and long term the clock at the receiving end is ultimately a slave to the data rate that is sent. However what controls the average data rate that is sent? The clocking out of data from the CD player or Blu-ray player will be governed by a frequency that is synthesised and/or divided by reference to a crystal oscillator. This will provide ample stability. Over time, a small drift of so many parts in a million may occur. That is of no consequence to the human ear. I accept that some designs may use an aggressively short time constant to search for a lock and maintain the lock, but the question must still be asked: "is the additional jitter created by an aggressive phase locked loop audible?". If it is not audible, then the engineer has done a sufficient job for human ears, despite the additional jitter being measurable.


And so we turn to short term variations. You stated at post #801 of this thread:
"system noise can couple into the DAC clock independent of what the input is doing, to induce jitter"

Well I would suggest it is a very poor design that would allow that to occur to a significant extent, assuming such induced jitter is audible.

I will round off by clarifying that I did not mean certain things that you took me to be implying. In particular, you stated:
Quote:
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This was the crux of your statement which is the implication that buffering removes jitter and hence, why worry about listening test. That is proper logic, but wrong assumption. Buffering doesn't remove jitter so we can't make a statement about that in the context of audibility.
My statement was not to the effect that all buffering removes all jitter. It was a lesser statement, namely, "if there is doubt about the short term stability of a stream of incoming digital audio that doubt can be addressed by buffering".


I do not deny that real world buffering can leave measurable jitter, or even create additional jitter because of an aggressive phase locked loop that overshoots when attempting to correct the clock rate of the slave to match the master clock. However I would repeat what you yourself have stated: "There are solutions to this but it requires design skills, and a few dollars worth of parts...".


Moreover, there is still the challenge of actually establishing that any modern audio device creates audible jitter. Quoting "numbers" via graphs is simply quoting measurements. This does not establish that "superb performance" in minimising jitter is actually audible. I would suggest it is anathema to the Hydrogenaudio Forum to refer to measurements about "superb performance" without tying them to listening tests that demonstrate that the "superb performance" is actually audible.

Writing speculatively, I wonder whether the reason that some modern AVRs do not perform as well in measured jitter compared with certain venerable equipment is because the older equipment was conservatively over-engineered, for the avoidance of any possible doubt in the era of design as to audible performance. Jitter levels for some equipment may have been reduced by an order of magnitude or more below human audibility. Subsequent experience may have revealed that such conservative practices were unnecessary, or "overkill".
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post #806 of 940 Old 12-28-2014, 07:34 AM
 
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I did not mean to imply that all attempts to address jitter through buffering are successful in terms of measured reduction in jitter.
That's fine but the assumption that in any case buffering improves jitter is still wrong. See my article on jitter and how our audio systems work: http://www.**************.com/Librar...dioJitter.html. For now, here is a brief overview.

Let's look at one of two cases here. That the DAC clock is running a bit faster than the source clock. In this case the buffer does nothing whatsoever because it never fills with any data! You are consuming data faster than it comes. So soon enough, you will run out of samples to play. While not a manifestation of jitter, this happens sometimes in a PC that gets too busy to feed audio samples to the sound card. You hear a glitch, pop or a pause in music. The operating system has huge amount of buffering available to it yet it does it no good when the sound card runs out of data to play. No matter how deep the buffer, if you the source is slower than the target, you will run out of samples.

You may think the opposite situation is helped with buffering. But such is not the case there either. Let's assume the DAC clock is slower so it is consuming data slower than it is being sent to it. Now the buffer comes into picture, storing data that starts to back up because the DAC can't consume them fast enough. What happens if the source is my cable box, feeding my AVR over HDMI? I leave the cable box on all the time. Let's say I do the same with AVR. After hours and days, any reasonable buffer will overrun and the source data is forced to be thrown away.

So you see that the buffer by itself in one case does nothing useful, and in the other case is a partial solution that eventually runs into a ditch.

Now, our problem would go away if somehow how we set our DAC clock to the same speed as the source clock in the Blu-ray player, Cable box, etc. But how do we do that? No, you can't use the sample rate of the audio! That is a nominal value. 48 Khz does NOT mean you will get 48,000 samples/sec. When video is authored for example for video, the timing may very well be modified to 47,999 or 48,020. You just don't know. The DAC must determine this unknown value somehow.

Unfortunately in addition to above authored variations we also have noise and timing variations that get induced into the source clock and cable that feeds our input. And our input circuit itself adds more noise and timing variations. So what the DAC clock sees is a combination of valid speed variations+invalid speed variations. There are good and lousy solutions to this problem. I won't get into them now but suffice it to say, mere deployment of a buffer does not contribute to either solution working.

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If they are unsuccessful then that is poor engineering if the purpose of the buffering is to reduce the jitter. If the purpose of the buffering is merely to stop overruns and underruns in the processing of the received datastream then the buffering has achieved its purpose.
The purpose of the buffer is not for jitter reduction. It is needed for other reasons. For example if you give a compressed bit stream, e.g. dolby digital, to the AVR/DAC, it would have to first decode it. That decoding happens in blocks of data at a time. So buffering that input chunk of input and output data is mandatory. Such buffering plays no role however in jitter reduction. Once you have the uncompressed PCM audio samples, you must then consume them at the rate that the source sets. It is this synthesis that can increase, or reduce the jitter. The buffer's role is immaterial other than its necessity in how the system operates.

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It is true that over the medium and long term the clock at the receiving end is ultimately a slave to the data rate that is sent. However what controls the average data rate that is sent? The clocking out of data from the CD player or Blu-ray player will be governed by a frequency that is synthesised and/or divided by reference to a crystal oscillator. This will provide ample stability. Over time, a small drift of so many parts in a million may occur. That is of no consequence to the human ear. I accept that some designs may use an aggressively short time constant to search for a lock and maintain the lock, but the question must still be asked: "is the additional jitter created by an aggressive phase locked loop audible?". If it is not audible, then the engineer has done a sufficient job for human ears, despite the additional jitter being measurable.
No. You are making idealistic assumptions here that are not backed by how the system works or the data we have in hand. The source clock is not a synthetic thing in the player. In the case of authored audio/video it is actually buried in the content on the disc itself! And at any rate, the audio samples are locked to the video rate. For every frame of video, you have x amount of audio samples. In other cases like the CD, the rotational speed of the media itself could be the source clock and that can have very high variation in clock. Similar jitter reduction systems as I have explained then needs to exist to reduce this jitter.

As to audibility, yes, that is the ultimate question. Problem is, you assume an answer for it and run with it. When you bought your last AVR/DAC, did you look at its jitter profile? And if so, how did you determine it did or did not have audible jitter? I suspect you didn't look at its jitter performance. Nor if you had, you would know how to evaluate its audibility. It is not like you could set up an ABX test and make the jitter come and go on demand. The jitter is always there so such testing is darn near impossible.

You take comfort in buffering doing good and an empty assumption that jitter must be inaudible and bought your gear. Sometimes not knowing is a good thing . Unfortunately I do know so can't go where you can. My son bought a $400 DAC because the cheaper one I had bought him would, just like the fancy internal sound card, pick up system noise as he played his games. He then came to me complaining the $400 DAC also not sounding good. I said let's go and measure it. While setting up my instrument I lectured him on placebo effect and how he is pretty much imagining what he thinks he is hearing. Then this monstrosity popped up:



Our source signal is the center spike. The ideal system would only have that and nothing else. Yes this DAC spits out jitter that shoots up 50 db above its noise floor! Not only that, it is distanced so far from our main signal that it is not subject to masking anymore. There is no way to make a case for inaudibility of jitter here. Buffering and all, you are in trouble.

But it gets better. Changing inputs gives us this clean as a whistle output:



We just proved that whatever buffering was there played no role at all as to whether there was, or was not any jitter.

Unfortunately the story does not end there. Instead of Media Player classic, we fired up Windows Media player, playing the identical test signal file on the PC. This is what we got now:



These are things that we think are "impossible." Which media player we use is not supposed to make any difference. Digital is digital, right? Buffering helps with jitter, right? Wrong!

We make wrong assumptions that lead us astray. You must verify your assumptions. You have not done so when you say buffering does this and that, or that jitter is or is not audible. You may very well be right about inaudibility but the moment you go on to say how the system works to eliminate the effect of jitter and that is not so, I will chime in .
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post #807 of 940 Old 12-28-2014, 08:28 AM
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Why did Classic perform better? Is it ever the case that the reverse is true?

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post #808 of 940 Old 12-28-2014, 08:49 AM
 
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Why did Classic perform better? Is it ever the case that the reverse is true?
Because of the way it works. Classic reads a small chunk and plays a small chunk. As such, it does not create a fury of system activity. WMP on the other hand would read a big chunk of the file first and then cruise. If you waited long enough for its initial buffering to finish, WMP performance was identical to media player classic. Otherwise that large initial system activity would bleed into the DAC.

This clearly indicates lack of isolation between the DAC and the PC server. System activity should never bleed into a DAC.

FYI, my son returned the DAC and I bought him a Peachtree Nova only to have him find a bug in there! The built-in resampling was clipping on some of his music! If he changed the system sample rate, it would go away. So he ditched that too and now has the Oppo DAC. The clipping is gone and he is happy with it. Hope to measure it soon....
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post #809 of 940 Old 12-28-2014, 03:53 PM
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I am in awe of Amir's ability to uncover huge flaws like this, again and again.

Or something.
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post #810 of 940 Old 12-28-2014, 04:14 PM
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Does Peachtree know about this?

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