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Shame on Sound on Sound
I was just reading my November issue, and noticed this whopper from
technical editor Hugh Robjohns: "The CD burner creates small bumps in the playing surface of the CD-R that the CD player can then detect. The spacing between each bump is critical to being able to detect and decode the data signal. But more importantly, the rising and falling edge (the beginning and end) of each bump is also critical, and this is the aspect that is most affected by different combinations of burn speed, disc media and the state of the laser." Oh, SOS... -- Jay Levitt | Wellesley, MA | Hi! Faster: jay at jay dot eff-em | Where are we going? http://www.jay.fm | Why am I in this handbasket? |
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#2
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"Jay Levitt" wrote in message ... I was just reading my November issue, and noticed this whopper from technical editor Hugh Robjohns: "The CD burner creates small bumps in the playing surface of the CD-R that the CD player can then detect. The spacing between each bump is critical to being able to detect and decode the data signal. But more importantly, the rising and falling edge (the beginning and end) of each bump is also critical, and this is the aspect that is most affected by different combinations of burn speed, disc media and the state of the laser." Oh, SOS... Maybe suffering from trying to 'talk down to the layman' where this was not necessary, and in fact quite counter-productive... geoff |
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#3
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"Jay Levitt" wrote in message ... I was just reading my November issue, and noticed this whopper from technical editor Hugh Robjohns: "The CD burner creates small bumps in the playing surface of the CD-R that the CD player can then detect. The spacing between each bump is critical to being able to detect and decode the data signal. But more importantly, the rising and falling edge (the beginning and end) of each bump is also critical, and this is the aspect that is most affected by different combinations of burn speed, disc media and the state of the laser." Oh, SOS... Maybe suffering from trying to 'talk down to the layman' where this was not necessary, and in fact quite counter-productive... geoff |
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#4
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"Geoff Wood" -nospam wrote in message ... "Jay Levitt" wrote in message ... I was just reading my November issue, and noticed this whopper from technical editor Hugh Robjohns: "The CD burner creates small bumps in the playing surface of the CD-R that the CD player can then detect. The spacing between each bump is critical to being able to detect and decode the data signal. But more importantly, the rising and falling edge (the beginning and end) of each bump is also critical, and this is the aspect that is most affected by different combinations of burn speed, disc media and the state of the laser." Oh, SOS... Maybe suffering from trying to 'talk down to the layman' where this was not necessary, and in fact quite counter-productive... geoff Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. Thanks Roach |
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#5
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"Geoff Wood" -nospam wrote in message ... "Jay Levitt" wrote in message ... I was just reading my November issue, and noticed this whopper from technical editor Hugh Robjohns: "The CD burner creates small bumps in the playing surface of the CD-R that the CD player can then detect. The spacing between each bump is critical to being able to detect and decode the data signal. But more importantly, the rising and falling edge (the beginning and end) of each bump is also critical, and this is the aspect that is most affected by different combinations of burn speed, disc media and the state of the laser." Oh, SOS... Maybe suffering from trying to 'talk down to the layman' where this was not necessary, and in fact quite counter-productive... geoff Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. Thanks Roach |
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#7
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In article ,
says... I was just reading my November issue, and noticed this whopper from technical editor Hugh Robjohns: "The CD burner creates small bumps in the playing surface of the CD-R that the CD player can then detect. The spacing between each bump is critical to being able to detect and decode the data signal. But more importantly, the rising and falling edge (the beginning and end) of each bump is also critical, and this is the aspect that is most affected by different combinations of burn speed, disc media and the state of the laser." Oh, SOS... Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. Pressed CDs have pits and lands ("bumps"). Burned CDs have dye that is turned either opaque or transparent by the laser (I forget which state is "default"). There are no bumps. -- Jay Levitt | Wellesley, MA | Hi! Faster: jay at jay dot eff-em | Where are we going? http://www.jay.fm | Why am I in this handbasket? |
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#8
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"Jay Levitt" wrote in message ... In article , says... I was just reading my November issue, and noticed this whopper from technical editor Hugh Robjohns: "The CD burner creates small bumps in the playing surface of the CD-R that the CD player can then detect. The spacing between each bump is critical to being able to detect and decode the data signal. But more importantly, the rising and falling edge (the beginning and end) of each bump is also critical, and this is the aspect that is most affected by different combinations of burn speed, disc media and the state of the laser." Oh, SOS... Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. Pressed CDs have pits and lands ("bumps"). Burned CDs have dye that is turned either opaque or transparent by the laser (I forget which state is "default"). There are no bumps. Other than having pits in lieu of 'bumps', I was of a mind that the causes for inaccuracy of the pit burn were pretty much as described. It *was* a rather large error to describe the read surface completely ass-backwards. -- David Morgan (MAMS) http://www.m-a-m-s.com Morgan Audio Media Service Dallas, Texas (214) 662-9901 _______________________________________ http://www.artisan-recordingstudio.com |
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#9
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"Jay Levitt" wrote in message ... In article , says... I was just reading my November issue, and noticed this whopper from technical editor Hugh Robjohns: "The CD burner creates small bumps in the playing surface of the CD-R that the CD player can then detect. The spacing between each bump is critical to being able to detect and decode the data signal. But more importantly, the rising and falling edge (the beginning and end) of each bump is also critical, and this is the aspect that is most affected by different combinations of burn speed, disc media and the state of the laser." Oh, SOS... Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. Pressed CDs have pits and lands ("bumps"). Burned CDs have dye that is turned either opaque or transparent by the laser (I forget which state is "default"). There are no bumps. Other than having pits in lieu of 'bumps', I was of a mind that the causes for inaccuracy of the pit burn were pretty much as described. It *was* a rather large error to describe the read surface completely ass-backwards. -- David Morgan (MAMS) http://www.m-a-m-s.com Morgan Audio Media Service Dallas, Texas (214) 662-9901 _______________________________________ http://www.artisan-recordingstudio.com |
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#10
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"Mike Rocha" wrote in message Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. There are no bumps in a CD-R. The changes are in the optical properties in a film of laser-sensitive dye. 'Bumps' (better known as 'pits') are unique to stamped CDs. geoff |
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#11
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"Mike Rocha" wrote in message Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. There are no bumps in a CD-R. The changes are in the optical properties in a film of laser-sensitive dye. 'Bumps' (better known as 'pits') are unique to stamped CDs. geoff |
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#12
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#13
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#14
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In article znr1100463138k@trad, says...
Or can't a "bump" be a change in reflectivity? I admit, I have tripped over bumps of that very type. Does it have to be a physical increase in the height of the surface of the disk? -- Jay Levitt | Wellesley, MA | Hi! Faster: jay at jay dot eff-em | Where are we going? http://www.jay.fm | Why am I in this handbasket? |
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#15
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In article znr1100463138k@trad, says...
Or can't a "bump" be a change in reflectivity? I admit, I have tripped over bumps of that very type. Does it have to be a physical increase in the height of the surface of the disk? -- Jay Levitt | Wellesley, MA | Hi! Faster: jay at jay dot eff-em | Where are we going? http://www.jay.fm | Why am I in this handbasket? |
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#16
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"Mike Rivers" wrote in message news:znr1100463138k@trad... In article DKNld.2969$J55.888@trnddc06 writes: Other than having pits in lieu of 'bumps', I was of a mind that the causes for inaccuracy of the pit burn were pretty much as described. It *was* a rather large error to describe the read surface completely ass-backwards. Can't bumps go down, too? Or can't a "bump" be a change in reflectivity? Does it have to be a physical increase in the height of the surface of the disk? It was an explanation of the principle of how a CD gets read, not a discourse on how the disks are manufactured. How many readers do you think care whether the bumps go up or down anyway? Bumps is bumps, and Sound on Sound ain't the AES Journal, or even Scientific American. Try driving over a bump in your car, then try again over a pit. There are NO bumps (or pits) in CD-Rs at all. Not upwards, downwards, or sideways. Sound On Sound is generally very concise. geoff |
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#17
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"Mike Rivers" wrote in message news:znr1100463138k@trad... In article DKNld.2969$J55.888@trnddc06 writes: Other than having pits in lieu of 'bumps', I was of a mind that the causes for inaccuracy of the pit burn were pretty much as described. It *was* a rather large error to describe the read surface completely ass-backwards. Can't bumps go down, too? Or can't a "bump" be a change in reflectivity? Does it have to be a physical increase in the height of the surface of the disk? It was an explanation of the principle of how a CD gets read, not a discourse on how the disks are manufactured. How many readers do you think care whether the bumps go up or down anyway? Bumps is bumps, and Sound on Sound ain't the AES Journal, or even Scientific American. Try driving over a bump in your car, then try again over a pit. There are NO bumps (or pits) in CD-Rs at all. Not upwards, downwards, or sideways. Sound On Sound is generally very concise. geoff |
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#18
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"Geoff Wood" -nospam wrote in
: "Mike Rocha" wrote in message Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. There are no bumps in a CD-R. The changes are in the optical properties in a film of laser-sensitive dye. 'Bumps' (better known as 'pits') are unique to stamped CDs. geoff You have ra-ceived a beump, one could get a concussion from such a beump. - Inspector Clouseau |
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#19
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"Geoff Wood" -nospam wrote in
: "Mike Rocha" wrote in message Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. There are no bumps in a CD-R. The changes are in the optical properties in a film of laser-sensitive dye. 'Bumps' (better known as 'pits') are unique to stamped CDs. geoff You have ra-ceived a beump, one could get a concussion from such a beump. - Inspector Clouseau |
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#20
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On Mon, 15 Nov 2004 00:35:54 -0500, Drily Lit Raga wrote
(in article ): "Geoff Wood" -nospam wrote in : "Mike Rocha" wrote in message Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. There are no bumps in a CD-R. The changes are in the optical properties in a film of laser-sensitive dye. 'Bumps' (better known as 'pits') are unique to stamped CDs. geoff You have ra-ceived a beump, one could get a concussion from such a beump. - Inspector Clouseau Brain Fart; happens now and then. Ty Ford -- Ty Ford's equipment reviews, audio samples, rates and other audiocentric stuff are at www.tyford.com |
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#21
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On Mon, 15 Nov 2004 00:35:54 -0500, Drily Lit Raga wrote
(in article ): "Geoff Wood" -nospam wrote in : "Mike Rocha" wrote in message Care to briefly correct the inaccuracy in that statement? I read it in the same issue and it sounded a little odd at the time but i didn't think much of it. Don't have too much background on that topic. There are no bumps in a CD-R. The changes are in the optical properties in a film of laser-sensitive dye. 'Bumps' (better known as 'pits') are unique to stamped CDs. geoff You have ra-ceived a beump, one could get a concussion from such a beump. - Inspector Clouseau Brain Fart; happens now and then. Ty Ford -- Ty Ford's equipment reviews, audio samples, rates and other audiocentric stuff are at www.tyford.com |
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#22
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#23
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#24
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I am impressed that you all take such stock of Sound On Sound that a
silly typo slip like this causes such consternation. It keeps us all on our toes -- and rightly so. I'm afraid this was a simple case of brain fade (or brain fart -- I like that... very apt!). It is indeed the case that the CD-R burning process uses a relatively high powered laser to cause the organic dye layer in the disc to darken when heated. Thus the affected sections of the organic layer allows less light through (and back) from the reflective layer below when read by a standard power laser. The opto-receiver therefore sees a varying intensity of reflected laser light according to the number and spacing of the 'burned' areas of the disc, and this represents the binary channel code recorded to the disc. 'Bumps' are indeed the restricted to pressed CDs, and produce the required varying intensity of reflected light through phase cancellation of the light reflected from the tops of the bumps and the surrounding lands. Apologies for any confusion caused in this detail of that particular Q&A. Kindest regards to all our readers, hugh |
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#25
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I am impressed that you all take such stock of Sound On Sound that a
silly typo slip like this causes such consternation. It keeps us all on our toes -- and rightly so. I'm afraid this was a simple case of brain fade (or brain fart -- I like that... very apt!). It is indeed the case that the CD-R burning process uses a relatively high powered laser to cause the organic dye layer in the disc to darken when heated. Thus the affected sections of the organic layer allows less light through (and back) from the reflective layer below when read by a standard power laser. The opto-receiver therefore sees a varying intensity of reflected laser light according to the number and spacing of the 'burned' areas of the disc, and this represents the binary channel code recorded to the disc. 'Bumps' are indeed the restricted to pressed CDs, and produce the required varying intensity of reflected light through phase cancellation of the light reflected from the tops of the bumps and the surrounding lands. Apologies for any confusion caused in this detail of that particular Q&A. Kindest regards to all our readers, hugh |
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#26
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#27
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#28
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On Mon, 15 Nov 2004 15:15:11 -0500, Mike Rivers wrote
(in article znr1100532431k@trad): In article writes: Brain Fart; happens now and then. Was the path of that fart from the brain to the asshole or the asshole to the brain? Makes a difference whether it's a pit or a bump. I surmise it was actually difficult to say because of a peculiar circular breathing technique that was employed. On the other hand, some might consider the first part of your query redundant!  Regards, Ty Ford -- Ty Ford's equipment reviews, audio samples, rates and other audiocentric stuff are at www.tyford.com |
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#29
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On Mon, 15 Nov 2004 15:15:11 -0500, Mike Rivers wrote
(in article znr1100532431k@trad): In article writes: Brain Fart; happens now and then. Was the path of that fart from the brain to the asshole or the asshole to the brain? Makes a difference whether it's a pit or a bump. I surmise it was actually difficult to say because of a peculiar circular breathing technique that was employed. On the other hand, some might consider the first part of your query redundant! Regards, Ty Ford -- Ty Ford's equipment reviews, audio samples, rates and other audiocentric stuff are at www.tyford.com |
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#30
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Jay, you serious?
I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. |
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#31
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Jay, you serious?
I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. |
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#32
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In article ,
xy wrote: Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. No. CD-Rs are not CDs. Not even a little bit. They are a dye image, and they do not have anything like the long-term stability of CD pressings. They also tend to have much higher error rates. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
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#33
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In article ,
xy wrote: Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. No. CD-Rs are not CDs. Not even a little bit. They are a dye image, and they do not have anything like the long-term stability of CD pressings. They also tend to have much higher error rates. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
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#34
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"xy" wrote in message om... Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. I'm feeling a little ignorant here myself, but factory replication is done from a reverse glass master and is 'stamped' much like vinyl was. It's a rather massive process involving a lot of robotics and sterile atmosphere. I've been burning CDs in the studio for almost 17 years and never realized the process involved tinting the dye rather than burning pits. How much we take for granted sometimes.... :-( -- David Morgan (MAMS) http://www.m-a-m-s DOT com Morgan Audio Media Service Dallas, Texas (214) 662-9901 _______________________________________ http://www.artisan-recordingstudio.com |
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#35
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"xy" wrote in message om... Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. I'm feeling a little ignorant here myself, but factory replication is done from a reverse glass master and is 'stamped' much like vinyl was. It's a rather massive process involving a lot of robotics and sterile atmosphere. I've been burning CDs in the studio for almost 17 years and never realized the process involved tinting the dye rather than burning pits. How much we take for granted sometimes.... :-( -- David Morgan (MAMS) http://www.m-a-m-s DOT com Morgan Audio Media Service Dallas, Texas (214) 662-9901 _______________________________________ http://www.artisan-recordingstudio.com |
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#36
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David Morgan (MAMS) wrote: "xy" wrote in message om... Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. I'm feeling a little ignorant here myself, but factory replication is done from a reverse glass master and is 'stamped' much like vinyl was. It's a rather massive process involving a lot of robotics and sterile atmosphere. I've been burning CDs in the studio for almost 17 years and never realized the process involved tinting the dye rather than burning pits. How much we take for granted sometimes.... :-( The idea is to keep a reflection from getting to the detector. Bumps use dispersion and dyes use absorption. I believe that in either case all that edges are used for is slaving the phase locked loop to give an indication of where the middle of the bit is. Slop at the edges is ok because the middle is bigger than the slop. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#37
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David Morgan (MAMS) wrote: "xy" wrote in message om... Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. I'm feeling a little ignorant here myself, but factory replication is done from a reverse glass master and is 'stamped' much like vinyl was. It's a rather massive process involving a lot of robotics and sterile atmosphere. I've been burning CDs in the studio for almost 17 years and never realized the process involved tinting the dye rather than burning pits. How much we take for granted sometimes.... :-( The idea is to keep a reflection from getting to the detector. Bumps use dispersion and dyes use absorption. I believe that in either case all that edges are used for is slaving the phase locked loop to give an indication of where the middle of the bit is. Slop at the edges is ok because the middle is bigger than the slop. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#38
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"xy" wrote in message om... Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. You were totally wrong ! geoff |
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#39
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"xy" wrote in message om... Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. You were totally wrong ! geoff |
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#40
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On Tue, 16 Nov 2004 17:55:04 -0500, David Morgan \(MAMS\) wrote
(in article czvmd.10267$pP5.2451@trnddc05): "xy" wrote in message om... Jay, you serious? I thought factory vs. home cd's were made basically the same way, but the factory had faster and more robust machinery. I'm feeling a little ignorant here myself, but factory replication is done from a reverse glass master and is 'stamped' much like vinyl was. It's a rather massive process involving a lot of robotics and sterile atmosphere. I've been burning CDs in the studio for almost 17 years and never realized the process involved tinting the dye rather than burning pits. How much we take for granted sometimes.... :-( Right, "regular" CDs are made by a physical stamping process from a reverse master (not unlike vinyl records). CD-R are laser burned. Regards, Ty Ford -- Ty Ford's equipment reviews, audio samples, rates and other audiocentric stuff are at www.tyford.com |
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