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#282
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Now we have proof (was tweaks and proof)
"Stewart Pinkerton" wrote in message
newsaqGc.31138$XM6.12730@attbi_s53... snip..snip.. If one need to study with the same level of expertise in any topics mentioned in RAHE before they can put forward their opinion then I say many must keep out of any discussion. No problem with putting forward your opinion, but you must *listen* to the rebuttals if you are to move the debate forward. haven't I? google and see for yourself. You have *no* proof that stray light affects lasers in commercially available CD players. You are taking the authors comments *entirely* out of context. Since you admit that you know nothing about physics, please refrain from drawing these incorrect conclusions from technical papers which you admit that you do not understand. Mr.Pinkerton, have your read the article? The article was quoted to prove that stray lights do exist and affect the laser. Is that so difficult to understand? Prof Sukow said that stray light do affect laser. He also said the project is useful, among others, music. Read. Sir. If the technical paper was irrelevant then say so by backing up with some explanation. You can talk why it is out of contect for the benefit of other readers. I have repeatedly emphasized that I know nothing about Physics. So why do you keep arguing on technical points with the physicists on this newsgroup? Maybe, to provide entertaiment for physicists after a hard day of DBT. |
#283
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tweaks and proof
S888Wheel wrote:
From: chung Date: 6/28/2004 3:49 PM Pacific Standard Time Message-id: S888Wheel wrote: From: chung Date: 6/27/2004 10:18 AM Pacific Standard Time Message-id: wjDDc.118970$HG.109026@attbi_s53 S888Wheel wrote: From: chung Date: 6/25/2004 11:32 AM Pacific Standard Time Message-id: S888Wheel wrote: From: (Nousaine) Date: 6/23/2004 4:10 PM Pacific Standard Time Message-id: Bromo wrote: On 6/20/04 11:09 PM, in article , "Nousaine" wrote: It's all hand waving with out any specifics. That would be the case here on both sides. Let me ask again. If I'm not mistaken you have said that anything that can be heard can be measured or perhaps that was more like 'if you can't measure a difference than there would be nothing to hear' or something similar. I then asked exactly what measureable differences would explain amp/cable sound ..... and I don't recall a response. Again what should we be measuring to confirm 'amp/wire' sound that we haven't already done? It might be that no one knows. If you notice something - even if 10 people were to denounce you - it does not mean you know the mechanism, nor are you the expert on what measurements to make. So how do they "design" products then .... by making random choices? Are some people just lucky? Why would you ask the consumer how the designer opperates? I suggest you pose those questions to actual designers and let them speak for themselves. Uh, Tom's intent of asking those questions is to make the consumer think about the questions. It seems that when many consumers do so the objectivists get very upset with any eroneous conclusions they may draw. Really? It seems like some of the people who came up with the erroneous conclusions get unhappy when it was pointed out to them why those conclusions were erroneous. I did not sense any objectivists getting upset over these erroneous conclusions at all. The question is better answered by the designers and the consumer is better served if the answers come form the designers. If you would say they "listen" to them for validation then I wonder why haven't any of them made listening test validation public? Ask the people who know, the designers. After all these years of debate you should have already considered this. Again, you missed Tom's intent, which was to make you, the consumer, think. And question. I think I get his intent. It looks very much like a shell game played on consumers who are not technically qualified to discuss such issues. Wait a minute. Tom was asking some very general questions on the design process. I would think that someone not being very technical can still give an educated guess. What is the point of guessing? I think such guesses are nothing more than shark food. Or start thinking about an answer. Why? Some of us would really prefer to get at the best sound we can get without becoming EEs. In that case, you probably don't want to know the answer anyway. If the answers are not simple and easy for the layman to get then I am not that interestred. So why are you even interested in Tom's question? Because it looked to me like bait for a shell game. In case you have forgotten, Tom's question was how did the designers design those products, if, as Mr Bromo suggested, no one knows how to make measurements that show those products work. If that was the question then it was based on a false premise. Bromo never claimed "no one knows how to make measurements that shows those products work." Please read with more care. Here is what Tom asked: "Again what should we be measuring to confirm 'amp/wire' sound that we haven't already done?" To which, Mr Bromo replied: "It might be that no one knows. " The question posted by Tom was how did the designers design those products *if, as Mr. Bromo suggested,* no one knows how to make measurements that show those products work. Where is the false premise? Do you see a difference between "claimed" (your word) and "suggested"? Seems like a legitimate and fair question to ask on this forum. Perhaps it does until one realizes it may be premised on a flase assumption.But then you are speaking for Tom here. I thought that wasn't even allowed. Oh well. Why? You spoke for Mr. Bromo, no? And it can be considered a good rhetorical question, too. Personally I think good rhetorical question is an oxymoron. That does not seem to stop you from asking them... |
#284
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Now we have proof (was tweaks and proof)
"Chelvam" wrote in message ...
"Georg Grosz" wrote in message ... snip..snip.. I am an optical engineer. Prof. Sukow is describing a phenomenon that has been known about lasers since time immemorial. The techniques for overcoming this problem have also been known from time immemorial, and are quite simple to implement in a system like a CD player. Okay, a well known problem addressed since time immemorial. But would you state the margin of error among different laser pick up is uniform among different manufacturers. Or could there be in some laser mechanism the acceptable margin of error is higher than the others and would that affect audio quality? In terms of stray light in general, a diode laser is in fact remarkably insensitive to incoherent stray light for numerous reasons. The only potential problems occur when the laser has to eat some of its own output beam. Has this problem been eliminated or does it still occur? And what are the best ways to prevent laser eating its own output? In my experience, simple optical isolation of a laser diode can reduce the rate of mode hops (small but sudden step-function changes in output power and wavelength) to a few per hour or even less. At the same time, the circuitry monitors the laser power and adjusts the injection current, so the actual effect is just a "blip" or "dip" in the optical power. Meanwhile, if the detection circuitry is ratiometric, then it is probably insensitive to power fluctuations -- another technology known since time immoral ;-) My guess is that the error rate introduced by mode hops is either zero, or insignificant. This is especially because the errors are random, and thus can be corrected by various error recovery schemes used in CD players. But the details of the CD data system are out of my expertise. In a CD player, the important reflection is the one that is not accidental -- it is the full laser power reflected by the aluminized data surface. In this case, the reflection does not significantly alter the polarization of the laser, so a "simple isolator" is used. This is a polarizing beam splitter followed by a quarter-wave retarder plate. The round trip through the plate, to the CD, and back through the plate, results in a 90 degree polarization rotation, and the return beam is deflected by the beamsplitter instead of going back through to the laser. This has the added benefit of separating the return beam from the laser beam path so it can be focused onto a detector. A more elaborate optical isolator, (google Faraday Isolator) does not require the reflection to be polarization preserving, but is also much more bulky and expensive. It is used for things like telecom, high power lasers, and researchy applications. There is actually a simpler approach that sometimes works: Deliberate misalignment, so the reflected beam simply misses the laser. In most laser optics, surfaces are deliberately tilted in order to eliminate feedback and cavity resonances. Deliberate defocusing also works, if the system can tolerate it. Unfortunately, neither of these works when there is a highly reflective object at a focal plane -- exactly the situation required for a CD player. |
#285
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Now we have proof (was tweaks and proof)
Chelvam wrote:
"chung" wrote in message ... snip..snip.. Are you interested in audible degradations, or any measureable degradations? Neither, just want to know why my player B (if you remember that posting) sounds better than a more "modern" player. I want to know why I should be satisfied with a $500 player over ,say a Esoteric. So you are only interested in the sound differences, which are caused by audible degradations. Seems like you should be doing controlled listening tests then to verify that there are audible differences first. |
#286
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Now we have proof (was tweaks and proof)
On 6 Jul 2004 16:09:21 GMT, "Chelvam" wrote:
Thank you, your explanation is precise and useful. Appreciated. To clarify one point - oversampling has *nothing* to do with error cortrection. Data redundancy and error correction are achieved via the use of a cross-interleaved Reed_Solomon code (CIRC) data structure which scatters the data around the disc in such a way that even drilling quite large holes in the disc will not cause any data loss. It should also be noted that as a result, the data structure on the disc bears no simple relationship to the analogue output signal, so the notion that any effect on data reading can translate to such effects as 'muddy bass', or 'splashy treble' is quite ludicrous. "Cosworth" wrote in message ... If they are not read because of light scattering or any other reason, you get errors which are often corrected because of redundancy built into the system (oversampling), but if they're not read you don't get less hi-end or muddy bass--you get skips and chirps. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#287
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tweaks and proof
On 7/7/04 3:07 AM, in article 6jNGc.36270$a24.31089@attbi_s03, "chung"
wrote: In case you have forgotten, Tom's question was how did the designers design those products, if, as Mr Bromo suggested, no one knows how to make measurements that show those products work. If that was the question then it was based on a false premise. Bromo never claimed "no one knows how to make measurements that shows those products work." Please read with more care. Here is what Tom asked: "Again what should we be measuring to confirm 'amp/wire' sound that we haven't already done?" To which, Mr Bromo replied: "It might be that no one knows. " The question posted by Tom was how did the designers design those products *if, as Mr. Bromo suggested,* no one knows how to make measurements that show those products work. That would be what I said - to clarify, there may be a listenable difference in the amp-wire-speaker combination - but based upon the way measurements are done, it is possible we have missed something. No shame in that. Where is the false premise? Do you see a difference between "claimed" (your word) and "suggested"? |
#288
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Now we have proof (was tweaks and proof)
chung wrote:
Chelvam wrote: "chung" wrote in message ... snip..snip.. Are you interested in audible degradations, or any measureable degradations? Neither, just want to know why my player B (if you remember that posting) sounds better than a more "modern" player. I want to know why I should be satisfied with a $500 player over ,say a Esoteric. So you are only interested in the sound differences, which are caused by audible degradations. Seems like you should be doing controlled listening tests then to verify that there are audible differences first. My impression is that at this point he's mainly interested in offering what he *thinks* is evidence in support for his sighted impressions, without much understanding of the actual value or applicability of such evidence to his experience. -- -S. "We started to see evidence of the professional groupie in the early 80's. Alarmingly, these girls bore a striking resemblance to Motley Crue." -- David Lee Roth |
#289
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Now we have proof (was tweaks and proof)
On Wed, 07 Jul 2004 07:08:11 GMT, "Chelvam"
wrote: "Stewart Pinkerton" wrote in message newsaqGc.31138$XM6.12730@attbi_s53... snip..snip.. If one need to study with the same level of expertise in any topics mentioned in RAHE before they can put forward their opinion then I say many must keep out of any discussion. No problem with putting forward your opinion, but you must *listen* to the rebuttals if you are to move the debate forward. haven't I? google and see for yourself. You have not *listened*, you have merely searched for more obscure quotes which *on the surface*, appear to support your preconceptions. You have *no* proof that stray light affects lasers in commercially available CD players. You are taking the authors comments *entirely* out of context. Since you admit that you know nothing about physics, please refrain from drawing these incorrect conclusions from technical papers which you admit that you do not understand. Mr.Pinkerton, have your read the article? Yes, I have, and I've also worked in laser labs. The article was quoted to prove that stray lights do exist and affect the laser. Is that so difficult to understand? Prof Sukow said that stray light do affect laser. He also said the project is useful, among others, music. Read. Sir. I did read - did you? Where did Sukow say *anything* about commercial CD players? Hint - nowhere. If the technical paper was irrelevant then say so by backing up with some explanation. You can talk why it is out of contect for the benefit of other readers. I already did - he was talking about *laboratory* setups to educate his students how *not* to design laser-based equipment. Surprise, surprise - Sony/Philips already know how to avoid these problems - and have done for twenty years. I have repeatedly emphasized that I know nothing about Physics. So why do you keep arguing on technical points with the physicists on this newsgroup? Maybe, to provide entertaiment for physicists after a hard day of DBT. It's not entertaining, just excessively hard work............... -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#290
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Now we have proof (was tweaks and proof)
"Stewart Pinkerton" wrote in message
... On Wed, 07 Jul 2004 07:08:11 GMT, "Chelvam" wrote: Yes, I have, and I've also worked in laser labs. I wish with your expertise in laser and electronics and almost in every High End brand you should come with an excellent budget CD Player of your own. I will buy them. |
#291
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Now we have proof (was tweaks and proof)
"Stewart Pinkerton" wrote in message
news:fm2Hc.41766$%_6.25609@attbi_s01... ... To clarify one point - oversampling has *nothing* to do with error cortrection. Data redundancy and error correction are achieved via the use of a cross-interleaved Reed_Solomon code (CIRC) data structure which scatters the data around the disc in such a way that even drilling quite large holes in the disc will not cause any data loss. I stand corrected. I must've misinterpreted an article in Mix Magazine 20 years ago. So what IS the purpose of oversampling??? Keep learning! Bill Balmer |
#292
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tweaks and proof
On Thu, 08 Jul 2004 05:58:24 GMT, B&D wrote:
On 7/7/04 3:07 AM, in article 6jNGc.36270$a24.31089@attbi_s03, "chung" wrote: In case you have forgotten, Tom's question was how did the designers design those products, if, as Mr Bromo suggested, no one knows how to make measurements that show those products work. If that was the question then it was based on a false premise. Bromo never claimed "no one knows how to make measurements that shows those products work." Please read with more care. Here is what Tom asked: "Again what should we be measuring to confirm 'amp/wire' sound that we haven't already done?" To which, Mr Bromo replied: "It might be that no one knows. " The question posted by Tom was how did the designers design those products *if, as Mr. Bromo suggested,* no one knows how to make measurements that show those products work. That would be what I said - to clarify, there may be a listenable difference in the amp-wire-speaker combination - but based upon the way measurements are done, it is possible we have missed something. No shame in that. I's nothing to do with measurements - there is simply *no* evidence that *anyone* can hear differences among nominally competent cables. Until the premise of 'cable sound' can be shown to *exist*, why should we be measuring anything? -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#293
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Now we have proof (was tweaks and proof)
"Chelvam" wrote in message news:YTeHc.47164$Oq2.3553@attbi_s52...
"Stewart Pinkerton" wrote in message ... On Wed, 07 Jul 2004 07:08:11 GMT, "Chelvam" wrote: Yes, I have, and I've also worked in laser labs. I wish with your expertise in laser and electronics and almost in every High End brand you should come with an excellent budget CD Player of your own. I will buy them. Why re-invent the wheel? You can already get an excellent budget CD player of your own at Target for less than $100 AFAIK. A few more dollars gets you a digital AM/FM tuner in the bargain. That's going to be my next stereo system -- an AM/FM/CD Discman on the bookshelf with the power amp hidden in the basement. |
#294
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Now we have proof (was tweaks and proof)
"Cosworth" wrote in message news:%_eHc.47204$Oq2.35597@attbi_s52...
"Stewart Pinkerton" wrote in message news:fm2Hc.41766$%_6.25609@attbi_s01... .. To clarify one point - oversampling has *nothing* to do with error cortrection. Data redundancy and error correction are achieved via the use of a cross-interleaved Reed_Solomon code (CIRC) data structure which scatters the data around the disc in such a way that even drilling quite large holes in the disc will not cause any data loss. I stand corrected. I must've misinterpreted an article in Mix Magazine 20 years ago. So what IS the purpose of oversampling??? Keep learning! Bill Balmer Oversampling simplifies the design of the analog portion of the anti-aliasing and anti-imaging filters, at the expense of more complicated digital filtering. But digital filtering is "free" because it is simply encoded into the control firmware of the recording / playback devices. Also, digital filters produce no noise of their own. |
#295
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Now we have proof (was tweaks and proof)
On Thu, 08 Jul 2004 16:46:49 GMT, "Chelvam"
wrote: "Stewart Pinkerton" wrote in message ... On Wed, 07 Jul 2004 07:08:11 GMT, "Chelvam" wrote: Yes, I have, and I've also worked in laser labs. I wish with your expertise in laser and electronics and almost in every High End brand you should come with an excellent budget CD Player of your own. I will buy them. Don't bother. Sony, Technics and Cambridge have been making excellent budget players for many years. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#296
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Now we have proof (was tweaks and proof)
On Thu, 08 Jul 2004 16:54:19 GMT, "Cosworth"
wrote: "Stewart Pinkerton" wrote in message news:fm2Hc.41766$%_6.25609@attbi_s01... .. To clarify one point - oversampling has *nothing* to do with error cortrection. Data redundancy and error correction are achieved via the use of a cross-interleaved Reed_Solomon code (CIRC) data structure which scatters the data around the disc in such a way that even drilling quite large holes in the disc will not cause any data loss. I stand corrected. I must've misinterpreted an article in Mix Magazine 20 years ago. So what IS the purpose of oversampling??? It allows the use of a gentle low-order analogue reconstruction filter, leaving the 'brick wall' filter in the digital domain, where it can be easily (and cheaply) implemented with a very high degree of accuracy. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#297
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Now we have proof (was tweaks and proof)
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#298
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Now we have proof (was tweaks and proof)
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#299
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Now we have proof (was tweaks and proof)
"Rich.Andrews" wrote in message
news:qoSJc.88064$JR4.50240@attbi_s54... Nousaine, Are you asserting that WRT CDPs there is no audible difference between any of them or or you saying that low end players sound very much alike? The chances of 2 CD players sounding bad--and alike--are very poor. Things that sound bad usually sound bad in different ways. It's sort of like the clock analogy: A man wants an accurate clock, but he has no time standard to check them against. So he sets 5 clocks for the exact same time and comes back a month later. 4 of the clocks read the same within 5 seconds and the 5th one reads a minute fast. Would he buy the 5th one on the theory that the other four each lost a minute? Norm Strong |
#300
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Now we have proof (was tweaks and proof)
On 7/17/04 10:52 PM, in article IBlKc.106134$%_6.51857@attbi_s01,
"normanstrong" wrote: "Rich.Andrews" wrote in message news:qoSJc.88064$JR4.50240@attbi_s54... Nousaine, Are you asserting that WRT CDPs there is no audible difference between any of them or or you saying that low end players sound very much alike? The chances of 2 CD players sounding bad--and alike--are very poor. Things that sound bad usually sound bad in different ways. It's sort of like the clock analogy: A man wants an accurate clock, but he has no time standard to check them against. So he sets 5 clocks for the exact same time and comes back a month later. 4 of the clocks read the same within 5 seconds and the 5th one reads a minute fast. Would he buy the 5th one on the theory that the other four each lost a minute? Ah, but does he have an accurate standard to be able to know if it is 4 clocks that are acuurate-ish and one really not accurate? Buy an atomic clock receiver and be done with it! :-) |
#301
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Now we have proof (was tweaks and proof)
On Sun, 18 Jul 2004 20:53:10 GMT, B&D wrote:
On 7/17/04 10:52 PM, in article IBlKc.106134$%_6.51857@attbi_s01, "normanstrong" wrote: "Rich.Andrews" wrote in message news:qoSJc.88064$JR4.50240@attbi_s54... Nousaine, Are you asserting that WRT CDPs there is no audible difference between any of them or or you saying that low end players sound very much alike? The chances of 2 CD players sounding bad--and alike--are very poor. Things that sound bad usually sound bad in different ways. It's sort of like the clock analogy: A man wants an accurate clock, but he has no time standard to check them against. So he sets 5 clocks for the exact same time and comes back a month later. 4 of the clocks read the same within 5 seconds and the 5th one reads a minute fast. Would he buy the 5th one on the theory that the other four each lost a minute? Ah, but does he have an accurate standard to be able to know if it is 4 clocks that are acuurate-ish and one really not accurate? If you read the original post again, you'll se that it's a given that he does *not* have a time standard to check the clocks. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#302
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Now we have proof (was tweaks and proof)
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