| janneman |
| quote: | Originally posted by Kuei Yang Wang
[snip]Hmmm. The simple fact is that if you vibrate the CD (or player) the error rate will go up increasing the number of samples that are either repeated or interpolated instead of the real samples that should have been read. [snip] |
Completely wrong, Thorsten, I cannot believe you wrote this. Error correction is just that, error CORRECTION. After the error correction the data is 100% correct. Not 99.9999%, but absolutely 100%. Read '101 of CD players'.
Jan Didden |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by janneman
Think it through! "If the worst caps that we could find can't be detected" why does that AUTOMATICCALLY mean that the test is flawed? |
Because a SECOND piece of information, not explicitly referenced by John but assumed to be public domain general knowledge is the FACT that a number of Blind tests have ILLUSTRATED audible differences between different capacitors (especially electrolytic vs. Film).
Adding these two plus the observable levels of distortion which are usually reknowed audible (eg -60 to -80db THD is usually considered audible and can be illustrated in certain of the "worst" capacitors) then we do have a situation where test failing to reveal these must AT THE VERY LEAST be severely questioned, if not completely discarded.
| quote: | Originally posted by janneman
Why not conclude: 'It means that there is no audible difference'! |
Because prior and subsequent tests using a differnet, however still fully blind protoic reveal them reliably?
| quote: | Originally posted by janneman
There are billions of dollars made by companies based on these simple, well understood psychological issues. I continue to be amazed that the audio crowd is so insecure that they cannot even accept the existence of these phenomena. |
The "audio crowd" does accept the existence of exactly these phenomena, however, they do not accept it as the sole, complete and absolute explanation for all differences.
That particular dogma and doctrine is the domain of the "objectivist" fraction who will pelicanise any event that seems to violate their understanding of ' "common sense", that dreary bog of sullen prejudice and muddy inertia'. And as a results they invariably refuse to even consider the result of ANY particular investigation (including their own - D. Self is an excellent example - illustrating substantial and measurable differences between electrolytic, mylar and polypropylene capacitors and then promptly declaring that these diferences "do not matter") as giving evidence to the contrary of their 'sullen prejudice and muddy inertia'.
Sayonara |
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| janneman |
| quote: | Originally posted by Kuei Yang Wang
Konnichiwa,
Because a SECOND piece of information, not explicitly referenced by John but assumed to be public domain general knowledge is the FACT that a number of Blind tests have ILLUSTRATED audible differences between different capacitors (especially electrolytic vs. Film).[snip] |
Really? That would interest me definitely. Any pointers to where I could find this material?
BTW, Thorsten, how come you answer the post directed to John, but not the one (501) directed to you? I mean you guys ARE two different persons, no?
Jan Didden |
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| janneman |
| quote: | Originally posted by Kuei Yang Wang
[snip]The "audio crowd" does accept the existence of exactly these phenomena, however, they do not accept it as the sole, complete and absolute explanation for all differences. [snip] |
Of course not, who in his right mind would. In fact, who even claimed it did in this thread? Are you making this up?
Jan Didden |
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| geewhizbang |
About the pointy legs again.
1. Rubber legs would do a better job of vibration isolation.
2. The improvements in sound that he discusses don't sound like a problem with error correction / the effect seems to have nothing to do with skipping. He is talking about a more subjective finding that is very hard to explain using vibration as a reason.
3. If your CD player skips because of noise, that is because you have it on top of something that is resonating, or inside a boom box. The solid pointy legs would transmit this vibration very effectively.
4. The pointy legs he is using were orginally intended for speakers set on carpet AFAIK. The point is supposed to push thru the fibers and compress the carpet backing firmly so that the speakers are not as likely to rock. This supposedly tightens up the bass, improves imaging. This makes some sense, btw, but the effect is very slight if anything, I have tried it.
I do have some reason to be rather strongly skeptical of pointy legs having anything to do with improving the sound, since there is no logical physical explanation of it. You have proposed a couple and they don't make any sense.
They just look kewl, and more high end. So of course it sounds better to him. And it is ever so interesting that having them in front sounds better than in back, because that is what looks better too. |
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| SY |
| Jan, been drinking coffee again?:D |
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| sam9 |
| quote: | I do have some reason to be rather strongly skeptical of pointy legs having anything to do with improving the sound, since there is no logical physical explanation of it. You have proposed a couple and they don't make any sense.
|
The skepticsm maybe increased by comparing the explanations for pointy feet (does the "pointy haired boss" have pointy feet?). I have read that they isolate the unit, even that they are the mechanical analog to bypass caps; then I have read that they improve coupling to the surface on which the unit is placed. Logically, at least one of these must be false. |
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| analog_sa |
| quote: | | I'd like to plead with everybody to drop these stupid nicknames that keep cropping up ("Pelicanists" etc.) as alienating others |
Sorry. Just felt that Pelicanists is much friendlier than 'deaf robots' but also less desriptive. I'll stick to it for the time being.
| quote: | | Error correction is just that, error CORRECTION. After the error correction the data is 100% correct. Not 99.9999%, but absolutely 100%. Read '101 of CD players'. |
Simply untrue. Error correction under red book does not guarantee 100% correct data. There is simply not enough error correction code to guarantee this. |
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| squadra |
| quote: | Originally posted by geewhizbang
About the pointy legs again.
I do have some reason to be rather strongly skeptical of pointy legs having anything to do with improving the sound, since there is no logical physical explanation of it. You have proposed a couple and they don't make any sense.
|
This was the motivation -as I remember- for spikes underneath speakers on a hard surface:
Since spikes are pointy their area approaches zero mm^2 at the tip, and (my) speakers are heavy, which means the pressure (weight/area) on that small tip approaches infinity.
Small variations caused by i.e. vibrations therefore have no effect.
After all near infinity plus/minus a little still is near infinity.
What the effect is on lighter stuff like cd-players I don't know.
Pj |
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| geewhizbang |
The original purpose is to concentrate weight so the carpet backing firms up under the weight of the speakers.
On a hard surface they don't make much sense. But they do look kewl. |
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| geewhizbang |
If the error correction fails, you get outright errors, not subtle effects. Really nasty sounding errors.
So try again. |
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| Steve Eddy |
| quote: | Originally posted by janneman
Think it through! "If the worst caps that we could find can't be detected" why does that AUTOMATICCALLY mean that the test is flawed? Why not conclude: 'It means that there is no audible difference'! |
I would have to ask, why conclude that? Seems to me that such a conclusion would have to be based on the same sorts of preconcieved beliefs that has John concluding that the test is flawed.
Seems to me that the only firm conclusion that can be reached is that audible differences have yet to be proved.
se |
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| john curl |
Jan, I am now having my coffee, and let's hope that I can keep things on an even track. ;-) First, I feel that many on this thread have limited experience and knowledge to the accomplishments that we have made over the decades in audio design. Also, it is important that one actually has discussed ABX testing with the principal promoters of the test, in order to get as much understanding as possible about it, before deciding whether to use it or reject it. Many of you, who criticize me, don't seem to have 'walked the walked the walk, or talked the talk' that is necessary to have an informed opinion on the subject.
Folks, I must apologize when I 'brag' about my past published work, or that of others. It is easier to refer to it directly, rather than to give you an obscure reference, that most of you could never easily find, even if you wanted to bother.
In this case, it is important that I have done research on capacitor distortion and have published it, especially with regards to tantalum coupling caps.
As far as Thorsten is concerned: 'Keep on Truckin!'
For that degreed mechanical engineer who is so sure of his knowledge:
From 'The Experts Speak' once more: "I can accept the theory of relativity as little as I can accept the existence of atoms and other such dogma' Ernst Mach (Professor of Physics at the University of Vienna) 1913" p299
How about that? What a guy! Still, I have his textbook on my bookshelf.
Although I applaud anyone who has the drive to get a degree in engineering or physics, please learn your limitations. You will learn this from experience, soon enough. ;-) |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by janneman
Completely wrong, Thorsten, I cannot believe you wrote this. Error correction is just that, error CORRECTION. After the error correction the data is 100% correct. Not 99.9999%, but absolutely 100%. Read '101 of CD players'. |
I CANNOT BELIEVE that YOu wrote this! Are you COMPLETELY ignorant of how CD works?
Here a small Excerpt as to what I am on about (in short C2 and beyond):
| quote: | from http://www.cdrfaq.org/faq02.html#S2-17
"It is true that audio CDs use all 2352 bytes per block for sound samples, while CD-ROMs use only 2048 bytes per block, with most of the rest going to ECC (Error Correcting Code) data. The error correction that keeps your CDs sounding the way they're supposed to, even when scratched or dirty, is applied at a lower level. So while there isn't as much protection on an audio CD as there is on a CD-ROM, there's still enough to provide perfect or near-perfect sound quality under adverse conditions.
All of the data written to a CD uses CIRC (Cross-Interleaved Reed-Solomon Code) encoding. Every CD has two layers of error correction, called C1 and C2. C1 corrects bit errors at the lowest level, C2 applies to bytes in a frame (24 bytes per frame, 98 frames per sector). In addition, the data is interleaved and spread over a large arc. (This is why you should always clean CDs from the center out, not in a circular motion. A circular scratch causes multiple errors within a frame, while a radial scratch distributes the errors across multiple frames.)
If there are too many errors, the CD player will interpolate samples to get a reasonable value. This way you don't get nasty clicks and pops in your music, even if the CD is dirty and the errors are uncorrectable. Interpolating adjacent data bytes on a CD-ROM wouldn't work very well, so the data is returned without the interpolation. The second level of ECC and EDC (Error Detection Codes) works to make sure your CD-ROM stays readable with even more errors.
It should be noted that not all CD players are created equal. There are different strategies for decoding CIRC, some better than others." |
To be precise about the points I was originally refering to:
| quote: | from http://www.cdrfaq.org/faq02.html#S2-17
If there are too many errors, the CD player will interpolate samples to get a reasonable value. This way you don't get nasty clicks and pops in your music, even if the CD is dirty and the errors are uncorrectable. |
Some old players has outputs from the decoder which where puleld low if there where too many errors. They are no longer in existence. However, comparing the analogue output recorded from a CD player using a good quality soundcard with the raw data "ripped" from CD using bit accurate methodes with multiple reads is quite revealing too....
Sayonara |
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| geewhizbang |
| I can't believe that rubber feet cost more than a few cents each. Let's get real. Your gold plated feet cost $5.00 each. |
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| sam9 |
| quote: | quote:
Originally posted by janneman
Think it through! "If the worst caps that we could find can't be detected" why does that AUTOMATICCALLY mean that the test is flawed? Why not conclude: 'It means that there is no audible difference'!
I would have to ask, why conclude that? Seems to me that such a conclusion would have to be based on the same sorts of preconcieved beliefs that has John concluding that the test is flawed.
Seems to me that the only firm conclusion that can be reached is that audible differences have yet to be proved. |
I think what you have here is a microcosm of the problem most people have with scientific "proof"and causality. First, even proof that "A" causes "B" is difficult because even then certainty is never absolute; no mater how strong the evidence there is always the possibilty that the evidence will become weaker once a couple more decimal places of resolutioin can be achieved in measurement or that there may exist some "C" that causes both "A" and "B" which can be de-linked once "C" is understood.
If becomes more uncomfortable when we want to prove "A" does not cause "B". Strictly speaking, you can never say say this. The strongest statement is that no evidence has been found that supports "A" causes "B".
I thinks the average person is terribly uncomfortable with this state odf affairs. News media reflect this. You typically read "scientists have learned that. . ." . You you get the chance to talk to one of the people involved in the research about the strongest statement you will get is "Well, we're begining to think that . . ." or "The evidence seems to be pointing toward . . .".
A fairly small part of the population is comfortable with this state of afairs and can function with. An even smaller part wouldn't have it any other way - their worst nightmare is that all the questions get answered!
It's a minority od the population than operate on the basis that "A" (does not) causes "B" is subject to refution at any time but can comfortably make decisions and act as if it were certain. |
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| Peter Daniel |
| quote: | Originally posted by geewhizbang
I can't believe that rubber feet cost more than a few cents each. Let's get real. Your gold plated feet cost $5.00 each. |
So?? |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by janneman
Really? That would interest me definitely. Any pointers to where I could find this material? |
Capacitor Blind testing was in a number of issues of HFNRR in the UK over the decades, among others.
| quote: | Originally posted by janneman
BTW, Thorsten, how come you answer the post directed to John, but not the one (501) directed to you? |
After posting my answer to another item I scrolled upwards and first saw your post to John. I answered the other after I got out of a marathon meeting at work.
Sayonara |
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| fdegrove |
Hi,
| quote: | | I can't believe that rubber feet cost more than a few cents each. Let's get real. Your gold plated feet cost $5.00 each. |
It's about money again, is it?
First of all pointy feet (spikes) are very effective at draining energy away form whatever is on top of them into the underlying surface.
So if you have a speaker with a mildy resonating cabinet the spikes will do that and they will also provide for a fixed reference from which the cones can throw out energy into the environment.
Conversely, speakers on rubber feet, while damping because if their inherent compliance, will do this much slower and they will not provide a solid basis for energy transmission.
IOW, they are lossy.
Then there are cones... While their way of dealing with energy transmission is similar to spikes but not really the same as they are made directional on purpose, etc, etc...
Remember, anything that can move will inevitably lose energy.
And that's just scratching the surface and taking the thread OT but just applied physics all the same: no money from the Randi Crew for that one I'm afraid.
Cheers, ;) |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by geewhizbang
About the pointy legs again.
1. Rubber legs would do a better job of vibration isolation. |
Yes and no. NOT ALL rubber legs would make an improvement. The rubber will forma spring/mass resonant system with the component resting on it, at resonance the resulting amplitude may be higher than with just "pointy legs".
| quote: | Originally posted by geewhizbang
2. The improvements in sound that he discusses don't sound like a problem with error correction / the effect seems to have nothing to do with skipping. |
Error correction goes far beyond skipping or not. There is a wide range of states between the processor muting the data (skipping CD) and a completely accurate data, where a more or less large proportion is made up of linear interpolation "best guesses" of the processor, prior to Digital output and DAC.
| quote: | Originally posted by geewhizbang
He is talking about a more subjective finding that is very hard to explain using vibration as a reason. |
I repeat, vibrating the CD sufficiently can cause the error correction to be so overtaxed that it can no longer interpolate the missing data and mustes. Knowing how CD Error correction works (you do I hope, given that you make authorative statements about it) it stands to reason that there times where the error correction can still interpolate to avoid muting, but signal fidelity is sutably impaired, regardless of the DAC used etc.
| quote: | Originally posted by geewhizbang
3. If your CD player skips because of noise, that is because you have it on top of something that is resonating, or inside a boom box. |
The CD Platyer I could make skip with a sporano voice was a marantz CD-67, sited on a very heavy and rigid rack on top of a heavy slab of MDF and pitch based damping sheets on top of a bicycle inner tube limply inflated while sited at least 2m away from the speakers and with the rack "spiked" directly to a poured concrete slab, froming the floor of the groundfloor room. Trust me, the player was sited such that any direct transission of noise to it's chassis was minimal, apart from air pressure delivered sound sources.
| quote: | Originally posted by geewhizbang
The solid pointy legs would transmit this vibration very effectively. |
As there was very little vibration to transmit in the rack, what remains would have been rather effectively removed by the inner bicycle tube suspension and the "constrained layer" damping platform on which the Player was sited.
| quote: | Originally posted by geewhizbang
4. The pointy legs he is using were orginally intended for speakers set on carpet AFAIK. |
Hmmmm. As Far As You Know is non too far.
| quote: | Originally posted by geewhizbang
I do have some reason to be rather strongly skeptical of pointy legs having anything to do with improving the sound, since there is no logical physical explanation of it. |
You cannot concieve a physical explanation that would agree with your sullen prejudice and muddy mental inertia. That is not the same as there not being any.
| quote: | Originally posted by geewhizbang
You have proposed a couple and they don't make any sense. |
Could that be related in any particlar way or fashion to a profound ignorance of how CD actually works and a blind and irrational believe in the Digital Mantra "CD - Perfect Sound Forever!"?
Sayonara |
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| geewhizbang |
As an engineer I find it astonishing that one would want to spend money for something that has no purpose, other than reassure the builder that every precaution has been taking, including ones that make no sense.
Part of the MY purpose for DIY is to get a better bang for my buck. I think this is right in with the topic of this thread, because it is a perfect example how various ideas get passed around and become gospel, even those that don't make any logical sense.
I understand the theory about the speakers on carpet, but again, if the speakers are on a wood floor, you would be better off with rubber. Not only because that would scratch the floor less, but because the rubber would absorb some vibrations.
Even so the effect would be very slight.
What I'm talking about is putting spikes on a CD player. This CD player is almost certainly going to set down on a hard surface. So the spikes are not going to damp anything. They cannot transmit "energy" to a stiff piece of wood/mdf/ glass/marble etc. To do that the shelf would actually have to move or vibrate.
So I suppose you could put a rubber mat on the shelf then. That way you would get some damping, and the rubber would be moving to absorb the energy. But you would then get almost the same effect by simply putting rubber legs on the CD player or amplifier in the first place.
Any decent CD player is already mounted with shock absorbers inside the unit anyway. I would expect newer ones have a buffer so that they can do more than one attempt to read a passage.
And none of this explains the use of $15 worth of unnecessary pointy legs on a solid state amp, for goodness sake. |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by geewhizbang
If the error correction fails, you get outright errors, not subtle effects. Really nasty sounding errors. So try again. |
The Error correction first uses a checksum to attempt to restore the sample to the correct value. That failing it makes the whole frame from interpolation and that failing as the next farm is not there it repeats the previous frame and only after all possible methodes to conceal the error have failed ewill the processor mute the output (sending out digital silence samples).
How well the error correction copes is a question of design and programming, so at least in theory one should expect a high grade CD Player to have a pretty solid error correction. However, beyond a simple SINGLE SAMPLE not being read correctly the classic error correction is powerless and has to make up data to conceal that an error has occured.
So, I appreciate that your irrational religious believes do not allow you to admitt to it, but that are the facts, if you like them or not.
Sayonara |
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| Peter Daniel |
| quote: | Originally posted by geewhizbang
And none of this explains the use of $15 worth of unnecessary pointy legs on a solid state amp, for goodness sake. |
I can't believe what I read here.
Are you trying to say that because you don't find a reason for pointy devices to make sense as feet, I shouldn't be putting them on my amp, or offer such devices as an option for my chassis?
Are you completely lost in your self delusion?
That's the most arrogant request I've come across in a long while. |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by sam9
A fairly small part of the population is comfortable with this state of afairs and can function with. An even smaller part wouldn't have it any other way - their worst nightmare is that all the questions get answered! |
Count me to those to whom "no more questions to ask" (aka nothing more new to know) is a nightmare.... ;-)
Sayonara |
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| geewhizbang |
| quote: | | The CD Platyer I could make skip with a sporano voice was a marantz CD-67, sited on a very heavy and rigid rack on top of a heavy slab of MDF and pitch based damping sheets on top of a bicycle inner tube limply inflated while sited at least 2m away from the speakers and with the rack "spiked" directly to a poured concrete slab, froming the floor of the groundfloor room. |
And wow, it still didn't work right after all of this trouble. There were probably simpler solutions. I would think that you would get a pretty good isolation putting the unit on top of small peices of thin plywood or cardboard underneath each leg with a peice of foam or even that gel stuff from shoe inserts glued to the bottom of each peice.
Total cost $1.00 to 6.00 depending on where you got the foam.
Perhaps you had a cavity resonance inside the case or the case itself was doing some sympathetic vibration. If it was the case, you could just glue some rubber to the inside of the case in a few places, and that would stop the vibration. If it was cavity resonance, then there would inexpensive ways to fix this as well.
I think the reason why you are attacking what I'm saying is that you enjoy this overengineering, so when some of us are trying to show why it is unnecessary, you don't like having us mess up your fun.
If you like being this elaborate, go ahead, but I doubt that much of your elaborate work actually benefits the sound.
I don't think CDs are perfect BTW. I prefer good analog. |
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| geewhizbang |
You can put them on there if you want to.
I just think it is almost laughably silly to use these pointy feet on an amp, speaking as an engineer. It is not arrogant of me to point it out.
It is akin to the hood ornaments on luxury cars, which were originially there because the top-mounted external radiator cap had a thermometer in it that could be seen on the driver's side. Cheap cars didn't have thermometers so they didn't need ornaments. Hood ornaments thus got associated with expensive cars and we were stuck with the silly (and actually dangerous) things on American luxury cars for another sixty years, long after their original purpose was engineered away.
So you put the feet on because that looks "audiophile" to you. And pyschoacoustically, that just happens to sound good. But it is just as laughable as the hood ornaments on old big boat American cars. |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by geewhizbang
As an engineer I find it astonishing that one would want to spend money for something that has no purpose, other than reassure the builder that every precaution has been taking, including ones that make no sense. |
Well, in the ol engineering lingo they called that the "belt & braces" approach. BTW, much of the old "belts & braces" approach based mostly on "Engineers folk tales" was later shown to have real effects which where merely not well understood at the time and hence became an enginneres folk magioc tale "Do this and it will work". I am the first to prefer knowing what I do and why, bt I'm not averse to "it works, no idea why, but it still works".
| quote: | Originally posted by geewhizbang
Part of the MY purpose for DIY is to get a better bang for my buck. |
Then you are wrong doing DIY. If you consider the economics of scale of mass production you are much better off working some paid overtime and buying a mass produced gadget, at least monetary.
DIY allows you control over variables often considered "unimportant" or "non existent" by mainstream engineers which you consider relevant.
| quote: | Originally posted by geewhizbang
I think this is right in with the topic of this thread, because it is a perfect example how various ideas get passed around and become gospel, even those that don't make any logical sense. |
Yup, yours and Mr Diddens insistence on the "perfect data being read from CD" is an excellent illustration of tof how such illogicall, obviously false ideas are being passed around and become the gospel, facts to the contrary nonwithstanding.
| quote: | Originally posted by geewhizbang
What I'm talking about is putting spikes on a CD player. This CD player is almost certainly going to set down on a hard surface. |
And the resonances in the ssytem formed out of the CD Player chassis, coupling mecahnism and shelf will have several resonance modes. These will differdepending upon the type of coupling element, it's placement and many other variables.
| quote: | Originally posted by geewhizbang
So the spikes are not going to damp anything. They cannot transmit "energy" to a stiff piece of wood/mdf/ glass/marble etc. To do that the shelf would actually have to move or vibrate. |
I suspect if you placed a stethoscope against the shelf you may find exactly that.
| quote: | Originally posted by geewhizbang
So I suppose you could put a rubber mat on the shelf then. That way you would get some damping, and the rubber would be moving to absorb the energy. But you would then get almost the same effect by simply putting rubber legs on the CD player or amplifier in the first place. |
Those are assumptions which may or not be scrutinised empirically, however I doubt that without either extensive realistic simulation/moddeling and/or real world experiments a clear conclusion can be drawn as to the results.
The only thing that can draw conclusions without real world data is blind faith, which you amply demonstrate, however as you no doubt know, blind faith is not exactly aknowleged as scientific proof.
| quote: | Originally posted by geewhizbang
Any decent CD player is already mounted with shock absorbers inside the unit anyway. |
So it is. And what is the sort of resonance frequency of the suspension, or in other words, below which sort of frequency does the suspension fail to actually isolate the mechanism and instead couples vibrations to the transport?
| quote: | Originally posted by geewhizbang
I would expect newer ones have a buffer so that they can do more than one attempt to read a passage. |
You may expect a lot. You may expect England to win a Football Worldcup. You may expect Mana to fall from the Sky in the Siunai Desert. You may expect the moon to be made from green cheese. You may even expect buffers and multiple reads of the same passage for CD players. HOWEVER, if you are even modestly aware of the reality surrounding these subjects you should know that while may expect a lot, very little of you expect will happen any time soon.
| quote: | Originally posted by geewhizbang
And none of this explains the use of $15 worth of unnecessary pointy legs on a solid state amp, for goodness sake. |
Unless you are aware (among other things) that electrolytic capacitors are strongly microphonic. Again, i agree insuylation would seem preferable, but some people prefer to tune resonances to a sound they like, who am I to cide them for that.
Sayonara |
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| Peter Daniel |
| quote: | Originally posted by geewhizbang
You can put them on there if you want to.
I just think it is almost laughably silly to use these pointy feet on an amp, speaking as an engineer. It is not arrogant of me to point it out.
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I have good laughs reading your silly posts as well. It may not be arrogant to point out, but it's rather arrogant to persist on the subject the way you do. And as far as I'm concerned, it started months ago.
You're not related to millwood by any chance? |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by geewhizbang
And wow, it still didn't work right after all of this trouble. |
Actually, it worked rather well, except with one specific note on one CD (Vivaldis Gloria with Emma Kirkby btw) played at realsitic levels. Nothing else seemed to phaze the player otherwise.
| quote: | Originally posted by geewhizbang
There were probably simpler solutions. |
Maybe, maybe not. I found that adding all this insulation below the player worked actually quite well and very little cost too.
| quote: | Originally posted by geewhizbang
Perhaps you had a cavity resonance inside the case or the case itself was doing some sympathetic vibration. |
That is likely, however the case had been quite extensively damped using heavy "pitch" mats normally used in quieting down cars and the like, so only the cavity resonance (or a resonance of the CD itself) remain, I was unabe to cure the problem (I tried, trust me).
| quote: | Originally posted by geewhizbang
If it was cavity resonance, then there would inexpensive ways to fix this as well. |
Possibly, however, the CD-67 has very littel internal space to fit any substantial material to damp cavity resonance without upsetting thermal management and I dislike running mainspowered equipment without cover.
| quote: | Originally posted by geewhizbang
I think the reason why you are attacking what I'm saying is that you enjoy this overengineering, so when some of us are trying to show why it is unnecessary, you don't like having us mess up your fun. |
Who said I am attacking you? Are you paranoid? IU merely am pointing out that your arguiments are severely flawed, logically and factually and not consistent with a scientific worldview but consistent with a religious one. I call that observation (empiricism if you will), not attack. Unless of to disagree polietly with you and to point your errors is an attack, a viewpoint which BTW is entierly consistent with a religious worldview and inconsistent with a scientific one, if I may add a further observation on the topic.
| quote: | Originally posted by geewhizbang
If you like being this elaborate, go ahead, but I doubt that much of your elaborate work actually benefits the sound. |
I have since learned a lot more about dealing with vibrations and the like, including quite a bit of far out stuff.
| quote: | Originally posted by geewhizbang
I don't think CDs are perfect BTW. I prefer good analog. |
Hmmm. Then surely you should be aware of how the medium works and exactly where there are weak points where the system falls down?
Sayonara |
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| geewhizbang |
You're still replying, so how am I persisting any more than you are?
Have you done an ABX test on this, btw?
I am persisting because you just got done supplying an answer to someone about selling them extra-expensive premium kit, that in all likelihood doesn't sound significantly better than the basic one. This bugs me for some reason.
I would like to to do a bit more research, such as an actual scientific test, before you make claims that certain components sound better than others. The pointy feet are the perfect example that you don't know what you are talking about, since it is so unlikely that they could have any effect on a solid state amp's sound.
The people that have posted here in your defense are using the language of science at times, but I don't think they quite understand enough physics to understand just how minimal the effects of these feet would be both in assisting vibration damping along with the rather small effects that vibration has on solid state components in the first place.
****
If you are building speakers, then building your own is about 1/4 the cost of buying good commercial ones, BTW.
I don't think that building amps is necessarily lower in cost, but I would enjoy the challenge. But at the same time, I don't want to be wasting effort or time on useless tweaks. |
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| sam9 |
| quote: | quote:
Originally posted by geewhizbang
And none of this explains the use of $15 worth of unnecessary pointy legs on a solid state amp, for goodness sake.
I can't believe what I read here.
Are you trying to say that because you don't find a reason for pointy devices to make sense as feet, I shouldn't be putting them on my amp, or offer such devices as an option for my chassis?
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This may sound cynical, but PD is totally rational for including point feet in his product. Very simply, a significant segment of his target market wants and expects pointy feet. If the feet are not there he is going to loose sales. The segment od his market that doesn't care for pointy feet will probably buy it anyway; very few will reject the product as a result of the points.
Now let us also posit that PD's product is sonicly one of the very best availabvle at the price sonicly. This means that PD is a true benefactor to mandkind and the more units sold the greater the benefit. Thus, even if pointy feet have no sonic benefit, the fact that they enourage sales and therefore allow more people to benefit from a superior product means that putting pointy feet on the unit is an act not only of commercial accumen but of kindness. It partially protects the public fom inferior products that also have pointy feet.
To point out a historical analog, if this were 1957 only a fool would offer a car without tail fins no matter how good a product it otherwise was! |
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| Peter Daniel |
| quote: | Originally posted by geewhizbang
I would like to to do a bit more research, such as an actual scientific test, before you make claims that certain components sound better than others. |
By all means do those tests. But don't expect me waiting for your results. |
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| geewhizbang |
Now I understand. The reason is totally illogical. Wow, we could have got here right from the start.
I really doubt that an amp that wastes $200 on non-audible "improvements" can be the best DIY amp for the money.
But 'nuff said. As long as your willing to admit finally that the reason is just marketing, I can understand even while I don't buy into it myself. |
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| geewhizbang |
| quote: | | By all means do those tests. But don't expect me waiting for your results. |
Of course, don't let the facts get in the way of making claims. |
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| sam9 |
| quote: | | The CD Platyer I could make skip with a sporano voice was a marantz CD-67, sited on a very heavy and rigid rack on top of a heavy slab of MDF and pitch based damping sheets on top of a bicycle inner tube limply inflated while sited at least 2m away from the speakers and with the rack "spiked" directly to a poured concrete slab, froming the floor of the groundfloor room. |
Truly, you should demand you money back! A Sony Discman behaves better. The ease with which cheap but reliable CD units can demonstratively be stamped out by rhe thousands and put in discmen, boomboxes, etc. suggests to me that the is absolutely no excuse of higher priced "audiophile" units to have ANY problems in the mechanical and data acqusition area.
This is not to imply that I think cheapo units are indistingushable with regard to the DAC--> analog chain . |
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| Peter Daniel |
| quote: | Originally posted by geewhizbang
I really doubt that an amp that wastes $200 on non-audible "improvements" ...
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Such as what, for instance?
Six walls and a heatsink? |
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| geewhizbang |
You operate in an entirely different plane of existence Peter. What seems so utterly reasonable to you seems like bad engineering to me.
I could build a very nice case for that amp that would be very attractive and cost about $50, if I built several of them at a time. I'm a pretty good amateur industrial designer, and almost anything I build people rather like. But I'm on a budget, and the $200 for the case is only somewhat less than what my speakers cost to build, and has almost nothing to do with the sound.
Then there is the premium golden-ear components, which are even more expensive yet.
The circuit boards and basic components are very reasonable, and fairly priced. But the heavily over-engineered case is an abomination. |
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| Peter Daniel |
| quote: | Originally posted by geewhizbang
As long as your willing to admit finally that the reason is just marketing, I can understand even while I don't buy into it myself. |
I'm not sure who you direct it to, but I'm not willing to admit that it's marketing. It's more about giving people a choice. The chassis is offered without any feet. Out of courtesy, I'm offering cones as this is the type of the footing that I observed to work the BEST with MY chassis. It's not even my amp, as it's not being sold as such.
You may argue about it or not, but whatever you say won't make much sense. |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by geewhizbang
Have you done an ABX test on this, btw? |
I have done a number of blind tests (I reject ABX as you might have noticed as biased towards returning false null results), not on this though.
Moreover I am not interested if it makes a difference or not and if the result with if preferred to that without.
What I have been interrested to do though was to point out that many of your pronouncements of what happens how are not based on any knowledge of any relevant facts or any logical progression, but instead on illiogic, pure blind faith that things "should be so and no other" and the liek, and that your behaviour in this discussion shows all the hallmarks of somone who argues fanatically from a dogmatic, religious viewpoint and not a scientific one.
Of course, you are entitled to your believes, no matter how irrational they may be, but if you want to share them you must accept criticsm of them or simply shut up.
| quote: | Originally posted by geewhizbang
I am persisting because you just got done supplying an answer to someone about selling them extra-expensive premium kit, that in all likelihood doesn't sound significantly better than the basic one. This bugs me for some reason. |
Funny, I thought this place here was about DIY and the difference in discussion in your particular case was the cost difference between a set of rubber feet for two bucks in total and a set of metal feet for fifteen bucks in total, a in essence irrelevant difference, monetary speaking.
| quote: | Originally posted by geewhizbang
I would like to to do a bit more research, such as an actual scientific test, |
Suit yourself, however you may find the results of applying yourself to a scientific empirical examination of audio incompatible with retaining your current believe, you have been warned.
| quote: | Originally posted by geewhizbang
before you make claims that certain components sound better than others. |
I personally, here make no claims whatsoever that something sounds better one way or the other (though i may have remarked that TO ME PERSONALLY it sounded different and better), so no claim entered in any way.
| quote: | Originally posted by geewhizbang
The pointy feet are the perfect example that you don't know what you are talking about, since it is so unlikely that they could have any effect on a solid state amp's sound. |
Hmm. What particular research and data are you basing your pronouncement that "it is so unlikely that they could have any effect on a solid state amp's sound" upon? I am sure you have such data? Data on how microphonic power transistors, electrolytic capacitors, resistors (especially SMD) are? And data to illustrate why such microphonic effects MUST BE HIGHLY LIKELY to be reliably below any audibility treshold.
Or do you lack such data and you merely have blind faith that such is the case?
| quote: | Originally posted by geewhizbang
The people that have posted here in your defense are using the language of science at times, but I don't think they quite understand enough physics to understand just how minimal the effects of these feet would be both in assisting vibration damping along with the rather small effects that vibration has on solid state components in the first place. |
Hmm. You missed my point entierly. What I was refering to was a change of RESONANCES. now if a resonance falls in the right place and is excited even substantially rigid and solid structures can showdisturbingly large amplitudes of displacement. As a degreed mechanical engineer you should be aware of the phenomenae of an army marching over a bridge in step and equally that in such a bridge providing another support point a short distance from the main one can drastically cut such resonance amplitude. Surely you see the parallels?
| quote: | Originally posted by geewhizbang
If you are building speakers, then building your own is about 1/4 the cost of buying good commercial ones, BTW. |
You may find that you are rather mistaken. Maybe you should read Nousaine on the topic? Most modern "Mid-Fi" speakers are likely to offer a flatter frequency response than any speaker you will be able to DIY using the normal set of acoustic tools available to you.
| quote: | Originally posted by geewhizbang
I don't think that building amps is necessarily lower in cost, but I would enjoy the challenge. |
You may find that in many cases inexpensive commercial amplifiers will comprehensively outperform your DIY Amplifiers in all commonly quantified parameters and thus (following your "logic") must be better, with a better finish and lower cost than you can achieve.
Why go through all the trouble UNLESS doing so gives you control over variables commonly not addressed? Now if such exist, surely it bears to at least consider with a reasonably open midn what they may be or not be.
| quote: | Originally posted by geewhizbang
But at the same time, I don't want to be wasting effort or time on useless tweaks. |
Well, you seem to prefer to waste it on making by hand and expensively devices that measure poorely compared to what is inexpensively available commercially. What a tomfoolery, if you ask me.
Sayonara |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by sam9
Truly, you should demand you money back! |
Why? The player gave stelar service on all other CD's and on the "problem disk" too, if I lowered the volume a little.
| quote: | Originally posted by sam9
A Sony Discman behaves better. |
How do you know? Have you actually experiemented with the stated recording played at high volume through speakers near the Sony Diskman, or are you merely putting blind faith into the "fact" taht a Sony Diskman would behave better?
| quote: | Originally posted by sam9
The ease with which cheap but reliable CD units can demonstratively be stamped out by rhe thousands and put in discmen, boomboxes, |
My wives Boom-Box is very "jumpy" at higher levels with VOCALS (not boom, boom bass), but there of course it is expected.
| quote: | Originally posted by sam9
etc. suggests to me that the is absolutely no excuse of higher priced "audiophile" units to have ANY problems in the mechanical and data acqusition area. |
The Marantz CD-67 was stamped out by the hundertthousands at least. It was a pretty decent mass-market "Mid-Fi" Player, in case you are ingnorant of it.
Sayonara |
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| sam9 |
| quote: | quote:
Originally posted by sam9
Truly, you should demand you money back!
Why? The player gave stelar service on all other CD's and on the "problem disk" too, if I lowered the volume a little.
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That particular problem disk no. Telacs 1812 with live cannon fire, yes. Also, when subjected to rather worse abuse than proximaty to a loadspeaker. Actually, the comparrison may not be fair since it is likeley that the Discman's design goals probably included a higher tolerance to mechanical shock than a a unit that just sits on a shelf. Under more normal conditions the Discman is limited sonicly. To me it sounds like limited headroom probably imposed on the analog section by the limited voltage swing you can get from a couple of AA batteries.
| quote: | quote:
Originally posted by sam9
A Sony Discman behaves better.
How do you know? Have you actually experiemented with the stated recording played at high volume through speakers near the Sony Diskman, or are you merely putting blind faith into the "fact" taht a Sony Diskman would behave better? |
See above, especially 1812 reference. Please don't get excited and think I'm praising a Discman as an audiophile source.
| quote: | :
quote:
Originally posted by sam9
The ease with which cheap but reliable CD units can demonstratively be stamped out by rhe thousands and put in discmen, boomboxes,
My wives Boom-Box is very "jumpy" at higher levels with VOCALS (not boom, boom bass), but there of course it is expected.
|
Well I guess my boombox is better than your boombox in this regard. <Shrug.> Point of curiosity: in the case of the vocals, is there any chance you are hearing a problem with the analog parts or the speakers? Mine clips and distorts like mad byond a certain point, but that wouldn't indicate anything amiss in the digital payback.
| quote: | quote:
Originally posted by sam9
etc. suggests to me that the is absolutely no excuse of higher priced "audiophile" units to have ANY problems in the mechanical and data acqusition area.
The Marantz CD-67 was stamped out by the hundertthousands at least. It was a pretty decent mass-market "Mid-Fi" Player, in case you are ingnorant of it.
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I'm not directly familiar with the CD-67, they all look a like after a while. Still whether mid-, low- or hi- fidelity, I think you should have a reasonable expectation that the problem you describe should not occur. I don't think you shouls be obligated to buy feet, pads or whatever to have the product perform correctly under circumstances that are one could reasonably expect to be encountered. |
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| john curl |
Folks, I just have to say that these comments and arguments are really basic, primitive, and elementary. How many of you have any experience about what you are talking about?
For example, in a college physics lab, I 'proved' that the 'area' of contact between two frictional blocks did NOT make any difference. This implies that auto tires should be skinny, as they have lower air resistance. They happen to be cheaper too! Have you tried this? Would you recommend it? |
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| FrankWW |
| quote: | | Actually, it worked rather well, except with one specific note on one CD (Vivaldis Gloria with Emma Kirkby btw) played at realsitic levels. Nothing else seemed to phaze the player otherwise. |
If you've ever stood next to a really hot singer in their "near field" when thy're singing out you will know that they can produce some very high SPLs in very narrow bands at @ 3000 Hz.
The lady probably nailed the exact resonant frequency of some small part or a defective connection to a small part
Hardly seems worth trying to find such a unique thing. Did you ever get another player of the same model and try the disc in it? |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by sam9
That particular problem disk no. Telacs 1812 with live cannon fire, yes. |
The 1812 I have never skipped, but as said, the problem was not a big shock, but a fairly high note sung at full tilt by a soprano (Emma Kirkby). The disk skipped reliably if the volume was above a certain point and failed to do so reliably below a certain point, the disk was absolutely pristine. I do admit to listening at high relaistic levels (front rows rather than stalls)
| quote: | Originally posted by sam9
Well I guess my boombox is better than your boombox in this regard. <Shrug.> |
Maybe, may also be related to music selection and volume levels....
| quote: | Originally posted by sam9
Point of curiosity: in the case of the vocals, is there any chance you are hearing a problem with the analog parts or the speakers? |
On my current system the disk plays fine (different player though similar Philips CD Mechanism) and no, it was nothing of the like. You could see the display blink on that point, just as normally if the CD Player looses focus on a bad disk and starts "hunting"....
| quote: | Originally posted by sam9
I'm not directly familiar with the CD-67, they all look a like after a while. Still whether mid-, low- or hi- fidelity, I think you should have a reasonable expectation that the problem you describe should not occur. I don't think you shouls be obligated to buy feet, pads or whatever to have the product perform correctly under circumstances that are one could reasonably expect to be encountered. |
I do think the conditions where extreme. When it comes to vibration insulation I still find that often using suspoensions as described works well. Note that this suspension was not required to make the player play reliably (except that one CD) but it did appear to improve the sound to my ears and quite significantly for three 3/4" tick 19" X 15" MDF pieces, two layers of self adheasive bitumen pads and a bit of glue plus a bicycle inner tube. Agreed, the same thing under my Kenwood KD-500 made a much bigger improvement, but that as they say is another story.
Sayonara |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by FrankWW
Did you ever get another player of the same model and try the disc in it? |
No, but my Philips CD720 (modified, but same transport mechanism and servo IC et al around the drive as Marantz) did exactly the thing. My Pioneer DVD player never did it.
Now I'm using a Shanling CD Player, it is also happy, despite using a similar Philips drive as the other two, but a different Servo IC.
Sayonara |
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| FrankWW |
The issue this thread keeps returning to is the relation between the device processes and how they are perceived by the listener.
And, relatedly, what's good reproduced sound?
We aren't the only ones circling around this. I don't want to copy the whole thing here because it's no doubt copyright and doesn't probably reflect the participants' exact positions today and I'd prefer they AES doesn't get incensed and take the thing private. Scroll down to AES-X129:
___________________________________________
http://www.aes.org/standards/b_repo...4-03-report.cfm
AES-X129. Loudspeaker Distortion Perception and Measurement
_____________________________________________
This article by Michael Gerzon, from 1990, illustrates and makes a good case, that remarkably small artifacts can have a large effect on perceived sound. He avoids generalizing but I don't have to and I'm left with the feeling the whole audio field probably is behind its engineering capabilites with regard to their application to psychoacoustic phenomenae. Except for the folk developing codecs.
http://www.audiosignal.co.uk/Why%20...0different.html
Reproduced from
Studio Sound, July 1990
Why do equalisers
sound different?
J |
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| john curl |
| Michael Gerzon was a genius! Right up there with Richard Heyser. Too bad that they both passed away so young. |
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| SY |
| John, look at what time it is. You're up too late for someone your age. Too much coffee! |
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| john curl |
| SY, I also read a copy of Gerzon's paper on phase shift, etc from the link above, before going to sleep! Great stuff, great guy, I miss him. |
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| SY |
"There ain't no such thing as magic." Gerzon recognized that.
As a minor point, classical uncertainty regarding conjugate variables preceded the quantum theory by quite a long time. But it's still a pretty interesting paper. |
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| janneman |
| quote: | Originally posted by analog_sa
Sorry. Just felt that Pelicanists is much friendlier than 'deaf robots' but also less desriptive. I'll stick to it for the time being.
Simply untrue. Error correction under red book does not guarantee 100% correct data. There is simply not enough error correction code to guarantee this. |
Untrue. You confuse error correction with error concealment. Quoting the red book is pretty risky if you don't actually read it.
Jan Didden |
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| janneman |
| quote: | Originally posted by Kuei Yang Wang
If there are too many errors, the CD player will interpolate samples to get a reasonable value. This way you don't get nasty clicks and pops in your music, even if the CD is dirty and the errors are uncorrectable. Interpolating adjacent data bytes on a CD-ROM wouldn't work very well, so the data is returned without the interpolation. The second level of ECC and EDC (Error Detection Codes) works to make sure your CD-ROM stays readable with even more errors.
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Aha! You were referring to error concealment rather than error correction! OK, I read you.
But we should all understand that error concealment is NOT a subtle process. It is immediately audible even during casual listening. It is a completely different thing than the subtle audible effects you, Thorsten, were suggesting that could be heard when error correction was caused (or cleaned up) by subtle changes in equipment.
Not only do these subtle effects not exist (as error correction is indeed 100% effective), if the manure hits the ventilator the effects are so gross that you are no longer talking about subtle effects due to subtle equipment changes.
So, far off the mark I'm afraid.
Jan Didden
(Where's my coffee again?) |
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| fdegrove |
Hi,
| quote: | | (Where's my coffee again?) |
SY took it....
Cheers,;) |
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| analog_sa |
| quote: | | You confuse error correction with error concealment. |
Confuse? You can call it whatever you like but concealment only occurs when correction fails.
It took you a while to come up with this explanation or should i call it 'concealment' |
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| janneman |
Well, I'm out of the country, moving from internet-cafe to internet-cafe, just because I enjoy the company of you guys so much, but yes, it involves what some scientist (help me here SY) called 'punctured equilibrium' .
My point is, and you would know it if you had read Thorstens original post I commented on that (repeat mode on) error correction corrects errors 100%. If that fails, the player switches to concealment mode, fro instance repeating a section and plugging that in the place of the corrupted section. It sounds often very similar to one of those primitive LP-players skipping and thereby repating a track.
His (Thorstens) point was IIRC, but I am sure he will correct me if necessary, that subtle equipmen changes, I think he mentioned acoutic/mechanical feedback, would activate error correction which would lead to subtle audible differences. Which, of course, is utter hogwash. If you have such gross acoustical/mechanical feedback that servo tracking is completely destroyed to the point that error concealment has to come to the rescue, you are way beond ' subtle changes'. But, I must say, his post, as most of them, superficially looked impressive.
Jan Didden |
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| janneman |
| quote: | Originally posted by Steve Eddy
I would have to ask, why conclude that? Seems to me that such a conclusion would have to be based on the same sorts of preconcieved beliefs that has John concluding that the test is flawed.
Seems to me that the only firm conclusion that can be reached is that audible differences have yet to be proved.
se |
Agreed Steve, I was only trying to say that there is as much (or as little) reason to chose one conclusion as the other one.
Jan Didden |
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| janneman |
| quote: | Originally posted by john curl
Jan, I am now having my coffee |
Lucky guy! I have to make do with Coke light...
| quote: | Originally posted by john curl
[snip]
In this case, it is important that I have done research on capacitor distortion and have published it, especially with regards to tantalum coupling caps.]snip] |
Of course that is important! If influences your perception big time!
| quote: | Originally posted by john curl
[snip]From 'The Experts Speak' once more: "I can accept the theory of relativity as little as I can accept the existence of atoms and other such dogma' Ernst Mach (Professor of Physics at the University of Vienna) 1913" p299
How about that?[snip] |
Err... Ahum... Who are you addressing? I mean, YOU are the guy in the know, if not the scientist here, saying, I've done this for 30 years, I KNOW what's real and what's not. Or do I misunderstand you?
Jan Didden |
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| janneman |
| quote: | Originally posted by Kuei Yang Wang
Konnichiwa,
[snip]Error correction goes far beyond skipping or not. There is a wide range of states between the processor muting the data (skipping CD) and a completely accurate data, where a more or less large proportion is made up of linear interpolation "best guesses" of the processor, prior to Digital output and DAC.
I repeat, vibrating the CD sufficiently can cause the error correction to be so overtaxed that it can no longer interpolate the missing data and mustes. Knowing how CD Error correction works (you do I hope, given that you make authorative statements about it) it stands to reason that there times where the error correction can still interpolate to avoid muting, but signal fidelity is sutably impaired, regardless of the DAC used etc.
[snip] |
Wrong again! Error correction has NOTHING to do with interpolation. You're really off your rocker here Thorsten. Error correction uses redundant data to EXACTLY correct errors. If THAT fails, error concealment tries to best guess and fill in the blanks. But that's a whole different ball game. For futher explanation, please scroll back a few posts.
Jan Didden |
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| janneman |
| quote: | Originally posted by Kuei Yang Wang
Konnichiwa,
[snip] Mr Diddens[snip] |
It's DIDDEN, without the 's'. Thanks.
Jan Didden |
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| janneman |
| quote: | Originally posted by john curl
Folks, I just have to say that these comments and arguments are really basic, primitive, and elementary. How many of you have any experience about what you are talking about?
For example, in a college physics lab, I 'proved' that the 'area' of contact between two frictional blocks did NOT make any difference. This implies that auto tires should be skinny, as they have lower air resistance. They happen to be cheaper too! Have you tried this? Would you recommend it? |
I happen to have done desert ralleys in Egypt. Guess what we put on the wheels of our 4-wheel drives when we got into dunes country? REAL skinny tires. Less resistance. True story!
Jan Didden |
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| janneman |
| quote: | Originally posted by john curl
Michael Gerzon was a genius! Right up there with Richard Heyser. Too bad that they both passed away so young. |
Lessee, I have a design reviewed by Jean Hiraga in La Nouvelle Revue du Son (successor to L'Audiophile), (OK, it was 1998, but still!), I also have a picture of myself and that marketing genius Mark Levinson. Do I get any points for that?
Jan Didden |
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| SY |
| Jan, the term you were searching for is "punctuated equilibrium," coined by the paleontologists Niles Eldridge and the late Stephen Jay Gould. Read all about it in Gould's "Structure of Evolutionary Theory," yet another book which doesn't hesitate to use ten words where one will do. |
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| fdegrove |
Hi,
| quote: | | Lessee, I have a design reviewed by Jean Hiraga in La Nouvelle Revue du Son (successor to L'Audiophile), (OK, it was 1998, but still!), I also have a picture of myself and that marketing genius Mark Levinson. Do I get any points for that? |
Lessee....2/5?
La Nouvelle Revue Du Son is the succesor of La Revue Du Son.
L'Audiophile was simply abandoned by the same publishing house that also happens to publish LED and a handful of other "technical" magazines after they abrubtly ended series 2 of that famous monthly.
If you want to see how those guys show what NOT do to with tubes, buy a copy and have a good laugh...
Mr. Jean Hiraga is now editing director of La Nouvelle Revue Du Son.
For an explanation on how to build commercial triangles and how to learn the art of reading between the lines of economic interests send me a private e-mail....:D
Cheers,;)
/Still sipping my coffee at 22.20....SY will have to put me to bed again.... |
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| Kuei Yang Wang |
Konnichiwa,
| quote: | Originally posted by janneman
Wrong again! Error correction has NOTHING to do with interpolation. |
It has EVERYTHING to do. The checksum allows only MINIMAL correction of errors. If a sample is read wrongly it MAY be restored to the normal value, but it MAY not be resotred. If two samples fail to read corretly they are both lost irecoverably by the "error correction" and in turn are interpolated.
| quote: | Originally posted by janneman
Error correction uses redundant data to EXACTLY correct errors. |
CD Data, as opposed to CD - ROM data has ZIP redudancy in the Data. Full stop. NO reduany, only a checksum per pair of samples!
| quote: | Originally posted by janneman
If THAT fails, |
The very little error correction CD has fails if you LOOK to hard at it.
Sayonara |
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| RHosch |
| quote: | Originally posted by john curl
Folks, I just have to say that these comments and arguments are really basic, primitive, and elementary. How many of you have any experience about what you are talking about?
For example, in a college physics lab, I 'proved' that the 'area' of contact between two frictional blocks did NOT make any difference. This implies that auto tires should be skinny, as they have lower air resistance. They happen to be cheaper too! Have you tried this? Would you recommend it? |
The area of contact does not make a differences to the dynamic friction force developed between the surfaces, as you correctly found in your "basic, primitive, and elementary" physics lab, so long as the normal force between surfaces is unchanged.
If would you really like to know why wider tires typically develop more grip than skinny ones (in cornering, or on a drag stip), continue reading. The limiting factor in DRY conditions for the majority of vehicles isn't dynamic friction force developed between the tire and road surfaces, which is what your lab experiment measured. It is in fact the shear strength of the rubber tire itself (as evidenced by the skid marks usually left once that limit is reached!). You may have also discovered in that primitive lab that the shear load supported by an object is directly proportional to the shear area... something wider tires do provide more of in most circumstances. Of course, there are always exceptions and complications, and sometimes a tall skinny tire has the same contact patch as a short wide one. You'd be surprised how much friction force they can develop as well. And in wet conditions, shear force is not the limiting factor due to the decreased coefficient of friction between tire and road surface... at that point you are back to dynamic friction. You might have noticed that wide tires don't buy you anything in terms of wet weather grip. ;)
What disturbs me the most is this attitude that only 25 years of work in the field is sufficient to allow one's opinion to become valid. Someone should have told Einstein that. Above I demonstrated the principle of agruing facts and physics, not posturing and prideful boasting. I could have simply pointed out that your knowledge of mechanical principles is obviously limited and erroneous, that your experience is outside that field, and as your anecdotes are therefore worthless you should probably just keep silent on issues you know nothing about.
But then that would be rude and condescending, like so many other posts in this thread. I'd much rather offer a real explanation for what you observed, hoping to simultaneously educate and keep the peace. It's the gentlemanly thing to do, is it not? Perhaps many of us would do well to make greater attempts at being civil. I for one freely admit that my frustration with some forum members is directly apparent in my terse responses. I did call Eastern philosophy silly, after all. I'm sure there was a more constructive way to make my point.
Here I find myself rambling, and I hope my point in this post was sufficiently clear, so for now I'll go back to silent mode... |
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| fdegrove |
Hi,
| quote: | | CD Data, as opposed to CD - ROM data has ZIP redudancy in the Data. Full stop. NO reduany, only a checksum per pair of samples! |
Now WTH is a CD-Data other than a CD-Rom with data on it?
Redundancy on a CD-Rom with data on it?
None, nothing whatsoever, if the file is damaged it's unreadable: end of story.
Cheers,;)
\Coffe kicking in bad, man...:xeye: |
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| TNT |
| :att'n: RHosch - great last post ! |
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| geewhizbang |
Kuei Yang Wang is going to keep on fulminating about this forever, no matter what we tell him. He wants to believe that all of his elaborate efforts to isolate his CD player using a lot of rather time consuming and costly elaborate vibration isolation methods that would be better applied to a turntable have been worth the effort.
He seems to think that CD players are so inaccurate that they are interpolating much of the time when they misread the disk.
To believe otherwise is to lose face about all of the elaborate work he has done.
You can put an extremely dirty data CD into a computer, and it very often reads the dang thing anyway. All of the files are perfectly error corrected. Just a single-bit error is enough to completely mess up the files, so I stand by my original point that there is no logical reason why putting pointy legs on a DAC could improve the sound.
For that matter you can put a rather dirty CD into a player and very often it will play properly. If it doesn't play properly, the effects are rather obvious.
I would like him to answer the following question, just to see how much science he actually understands:
| quote: | | If I place an object on a rigid shelf, it has a certain amount of weight. How much energy is being expended to hold the heavy item up on the shelf in opposition to gravity? |
I have a strong suspicion that he will get this one wrong. The explanation I have been given about the pointy feet improving vibration energy transfer appears to have at its very core a fundamental confusion between Force and Energy. |
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| analog_sa |
| quote: | | None, nothing whatsoever, if the file is damaged it's unreadable: end of story. |
Sorry Frank but we're not talking files here, just sectors. I can't say exactly how many bits the ECC can correct per sector but certainly quite a few. And voila your file is not damaged or unreadable any more even if a few bits are. The redundancy of course costs a lot in space. Something like 12% if i'm not mistaken. |
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| analog_sa |
| quote: | | You can put an extremely dirty data CD into a computer, and it very often reads the dang thing anyway. All of the files are perfectly error corrected. |
You don't seem to be able to comprehend that CDROM and audio CD is not the same.
Kuei is by far not the only one who hears the effects of support on the sound of CDPs. Whether these are due to ECC circuits working overtime, the effects of vibration upon the crystal jitter or a combined effect of multiple component microphony is open to debate. |
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| geewhizbang |
That really is laughable, ECC working overtime.
It either works or it doesn't. The ECC is a digital circuit; the transisto | | | |
