What count for high quality audio copying low jitter or low errors?

vbimport

#1

I am looking around for a burner. Since it is the DVD era now I am considering a DVD burner with good audio capabilities. My intitial choice is a Plextor because of it’s reputation.

My initial idea was that I need a low jitter burner on audio and assumed that low jitter means low error count. That is not quite true. Sometimes it seems to work the other way around.

So, what count for good audio performance? I most definately ask from a listening experience point of view. Technical considerations are also much appreciated as I am deep down still a tech oriented person. :stuck_out_tongue:

Is there any audiophile around this forum to share his experiences?


#2

Yes, a PX-712A would be a good choice. I understand the 716A is supposed to be even better at DAE, but I cannot confirm it as I don’t have one.

My initial idea was that I need a low jitter burner on audio and assumed that low jitter means low error count. That is not quite true. Sometimes it seems to work the other way around.

In my experience, there is no direct relation between BLER level and jitter rates. You can have a burn with low BLER and high jitter.

So, what count for good audio performance? I most definately ask from a listening experience point of view.
From listening point of view, BLER and jitter are irrelevant. You would never be able to hear any difference unless the jitter were so high that the player started skipping. Even an occasional C2 error should be inaudible as the player will simply interpolate from the neighboring samples. That is not to say you should tolerate C2 errors on your CDs; for me even one C2 spells a coaster. And the lower the jitter and BLER the better, of course. It is just not worthwhile worrying about these things too much because except in extreme dire cases youi won’t be able to hear a thing. But with the right Plextor/media/speed combo both jitter rates and C1 counts will be extremely low anyway.

I’m stating this before some “audiophile” nut jumps in spewing metaphysical bullshit he could never prove.


#3

And the lower the jitter and BLER the better, of course. It is just not worthwhile worrying about these things too much because except in extreme dire cases youi won’t be able to hear a thing. But with the right Plextor/media/speed combo both jitter rates and C1 counts will be extremely low anyway.
Thanks for the answers. It is good to know that low error count and low jitter may go hand in hand as they sometimes seem to correlate negatively. This brings up another question though.

Can anyone one tell if one needs to make a trade off between low jitter or low error count which one sounds better? Which of the two is the biggest influence on sound quality? And what are these qualities? I guess these things may make it’s self heard in the more subtle department. Think of terms like: detail, treble response, stage depth and width, pace and rythm, astmosphere, transient response, etc…

I’m stating this before some “audiophile” nut jumps in spewing metaphysical bullshit he could never prove.
On the other hand one may never know what interesting listening experiences a thorough audiophile may come up with. Or not of course. :o

To me it is worth the try anyway. Think I can handle the ideological load that may come with my type of question. It is only part of the fun… :cool:


#4

CD is a digital medium. So if you have a CD with no C1 or C2 errors at all (which does not exist) and a CD with a moderate amount of C1 and even some C2, these errors are all corrected by the CD player’s error correction and the same stream of ones and zeros is produced an sent to the player’s DAC. So you get the exact same output. Only if you have CU errors (E32) on the disc (which you will usually never have if you use halfway decent burners and media), the player needs to interpolate, which will become noticable as distortion or clicks if it gets too much. Also, if the C1/C2 error rate gets too high (say, more than 300 per second. I think the official specs are 280 BLER for a disc to be considered readable), the CD player might have difficulty reading the disc and start skipping. Again, with good burner and media you get error rates which are a hundred or even a thousand times lower than 300, so no need to worry.


#5

Looks like I wasted bandwidth for nothing.


#6

No, it wasn’t. :cool:

And thanks again for the provided info. It was one of the things I was interested in.


#7

No, it wasn’t. :cool:

And thanks again for the provided info. It was one of the things I was interested in. :iagree:

The reason for wanting to know these things is that I am dedicated to audio and it’s quality. I and others simply hear differences between a copy of a CD and the original CD. I would like to have as little as possible difference of course. Therefore I am also interested in possible correlations between technical measurement done in reviews and listening. As measurement make the search more efficient.

I modified my CD player to good effect. Part of the things I did in this project was on hard core digital engineering knowledge Wanna read some? Just let me know then I will give you some urls’s with serious documents from f.e. Philips). Other stuff was just trying a different type of opamp, resistor, capacitor etc…

I am experienced enough with the listening proces to know that there are audible differences. I am not flawless when it comes to the listening experience but try to keep an open mind for other input from audio friends etc.

I am old (36) and educated enough to know my way around in the ideological debate on a broad spectrum of issues. In the past I studied two years of Electronics and my grades were all but the reason to cop out. So, no need for a religious discussion with a tech religioius person who thinks that no external reference is needed for design criteria etc.

For example. Design criteria for harmonic and intermodulation distorsion for phone lines were based on criteria concerning the quality of reprodution spoken word of the person. The tech reference was derived from external sources.
DCC data reduction that Philips developed in the late 80´s was heavily based on psychoacoustic research. That knowledge was used for data reduction on CD signals. Again a tech reference derived from external sources.
Why would an amp need this little percent of distortion? Because I think 0,01% is a beautiful figure? Why not 3,14 ppm? As I think that pie (3,14…) is a beautiful figure? As I think 3,14 is such a beautiful and intriguing fundamental number in maths that therefore it should be true for distortion figures? I think it makes more sense to get the reference from systematic psychoacoustic research.

The question of jitter is also based on tech knowledge and listening experience of the audio community, and my own experiences in the modification proces that jitter plays a definite role in listening quality.
For DA conversion it turns out to be important that there is as little as jitter as possible at the moment of DA conversion. That is not nescessarily just data jitter. Au contraire, there are plenty of other sources that need to be seriously dealt with within the CD/DVD player in the first place.
Data jitter is the jitter that is measured in the tests of burners of tech sites. Data jitter is dealt with by the computer technicians. Too high data jitter simply corrupts the data.

There are thesis that suggest thet data jitter also may play a role in the quality of audio production. They suggest that it may be propagated by the power supply lines because the servo motors need to work harder. One of my steps with the above mod project will be bringing a stabilised power supply to the servo motors department. And listen wheather it has an effect.

But like I said I have no burner, yet, and cannot corroborate this type of thinking. But, like I said I try to keep an open mind for things.

So, regarding all the above mentioned reasons it was a deliberate choice to post in the audio department of the forum and not in the hard core tech sections because I am simply looking for possible correlations between listening experience and the measured quality of the burner. Would that be too much to ask for? I hope the above makes clear I am serious and systematic about this stuff and not some type of believer.


#8

> The question of jitter is also based on tech knowledge and listening
> experience of the audio community, and my own experiences in the
> modification proces that jitter plays a definite role in listening quality.
> For DA conversion it turns out to be important that there is as little
> as jitter as possible at the moment of DA conversion.

As you said yourself the jitter at the DA stage has nothing to do with jitter
on the recovered clock, which is what all the tools measure. These are two
completely separated signals, so no review will tell you which drive has the
lowest DA jitter. If you’re interested in audio quality, you should focus on
the player and not on the burner.

> There are thesis that suggest thet data jitter also may play a role in the
> quality of audio production. They suggest that it may be propagated by the
> power supply lines because the servo motors need to work harder.

That is wrong, mechanical parts don’t “work harder” because the jitter
of the recovered clock is higher. IF the mechanical parts “work harder”
(which you can see f.i. on radial/focus/tilt errors), THEN you could get a
higher data jitter, but even that is not for sure. For instance, a lack of
precision of the pits length will cause data jitter and nothing for the
mechanical parts (and nothing on the power supply).

As you can imagine this is not the first time we get such discussion here,
and most of us are on the tech side in the tech vs audiophile war :slight_smile:
Last time I checked all the “audiophiles” who claimed to hear differences
between discs without CU error failed the double-blind ABX test. Folks at
hydrogenaudio.org are specialized in hearing tests, it’s worth talking to them.


#9

It is because I am interested that I would like to investigate the borderline area between audio performance on the one hand and the burner on the other hand. Simply because I want to buy a quality burner of course and I am just curious about audio related stuff.

> There are thesis that suggest thet data jitter also may play a role in the
> quality of audio production. They suggest that it may be propagated by the
> power supply lines because the servo motors need to work harder.

That is wrong, mechanical parts don’t “work harder” because the jitter
of the recovered clock is higher. IF the mechanical parts “work harder”
(which you can see f.i. on radial/focus/tilt errors), THEN you could get a
higher data jitter, but even that is not for sure. For instance, a lack of
precision of the pits length will cause data jitter and nothing for the
mechanical parts (and nothing on the power supply).

Suppose the reading mechanics (I am talking the ones driven by servo motors) need to readjust many times to a possible bad quality burn or pressing (pit and land patterns) the excess of starting and stopping of the servos will result in extra current surges that causes an extra amount of switchnoise on the voltage lines. Trying to isolate the switch noise seems like a reasonable suggestion for an experiment then. And see if it has any effect.

What is the radial error? The other ones I can figure out myself. Tilt is about the angle of laserbeam/head with the disc surface. Focus error must be about adjusting the laser; but I don’t know wheater this is done mechanically or electronically.

As you can imagine this is not the first time we get such discussion here,
and most of us are on the tech side in the tech vs audiophile war :slight_smile:
Last time I checked all the “audiophiles” who claimed to hear differences
between discs without CU error failed the double-blind ABX test. Folks at
hydrogenaudio.org are specialized in hearing tests, it’s worth talking to them.

Tell me some more about the CU error test. That’s an interesting finding of course. In what environment was it performed etc…? Where there any, or how few/many, C2 errors on that disc?

That type of polarised discussion, is what I would like to prevent of course because it is not the background of my question. That is for people who know the Truth but don’t understand the virtue of Doubt. It seems to me that scientific/technological progress comes with doubt rather than loudly selling the Truth. I don’t care wheater an audiophile or a techy is venting.

Thanks for informing me about the community and it’s preferences. It sounds like a good idea to take a look the site of hydrogen.org then. As I will be out of town tomorrow for a long weekend and I won’t have much internet access then. So I would suggest to close he topic tomorrow. Not tonight, just in case some lost audiophile might stumble in this thread. :bigsmile:

Edit. Just took a look at hydrogen.org. It seems about hydrogen technology only. Are you sure you gave me the right sitename? :confused:


#10

He gave you the right address, but you shortened it; try www.hydrogenaudio.org :wink:


#11

An OPU has 4 degrees of freedom, 2 rotations (tangential and radial tilt)
and 2 translations (focus and radial), which are all handled with
electromechanical parts. Focus refers to the vertical moves perpendicular
to the disc and radial refers to the moves parallel to a radius of the disc.
The radial error is the distance between the center of your track
and your actual laser beam.

I read that in a thread about jitter at hydrogenaudio.org but I don’t find
it back right now. Best is to go there and ask directly Pio2001, I’m sure
he will point you to the relevant posts.

The problem is that too often audiophiles first swear they hear something,
then try to find any explanation to justify it, then they just stop instead
of proving their theory by scientific methods. Show me jitter plots of a DA
stage matching data jitter and power supply plots, then I’ll believe it ;
otherwise, it’s just “audiophile masturbation” as I call it. The audiophiles
I like are the guys who can explain what they do with scientific methods
(e.g. www.tentlabs.com), not the X-files fans.


#12

Thanks for the info. I used EMC publications of Guido Tent (found themat the site Audio Crafters Guild) on EMC to good effect in my CD player. Just a month ago I bought his clock. Needless to say the new clock does it’s job like Iwas promised.

Let me return the masturbation argument here. Scientism, look it up in the first introduction to Philosopy of Science you happen to lay your hands on, that’s using science for “selfstaining” activity.

Techies seem to mastrubate a lot on Science and or Technology. Then they deny catagorically the possibility of valid subjective observation. Like one of my non audio friends would call this type of behaviour. Beating people with the Book.:iagree:

To me the masturbation period seems a period in the person’s development of ideology. Like a friend told me about the first two years of studying Philosophy: “you then know the Truth and won’t stop arguing about it”. That disapperared in the later stages of her study.

Nuff said. Time to leave for almost a week of Belgium