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#1
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CD Quality Difference in Player
I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes
20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. -s |
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#2
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CD Quality Difference in Player
"Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#3
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CD Quality Difference in Player
"Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#4
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CD Quality Difference in Player
"Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#5
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CD Quality Difference in Player
"Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#6
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CD Quality Difference in Player
It has to do with the reflectivity of the CD media. The older players were
not too sensitive to the characteristics of the disks you would burn on your own burner. Most of the newer players manufactured today are very sensitive to be able to play the home burned CD's. On some of the older models, it is possible to force them to play the home burned CD disks, by going in there and doing a re-calibration of the player's alignment. In part of this recalibration, on purpose, the laser current may be able to be increased a bit. Specialized tools, training, and the service manual would be necessary to do this type of work. If the laser current is increased however, its life span will be shortened, because it was not designed to work at the higher intensity. I found that the blue reflective coloured media type CD disks were better for recording music to be played on standard CD players. I did some as long as 3 years ago, left them in the car all of the time (through winter and summer), and they still work very well. -- Greetings, Jerry Greenberg GLG Technologies GLG ========================================= WebPage http://www.zoom-one.com Electronics http://www.zoom-one.com/electron.htm ========================================= "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. -s |
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#7
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CD Quality Difference in Player
It has to do with the reflectivity of the CD media. The older players were
not too sensitive to the characteristics of the disks you would burn on your own burner. Most of the newer players manufactured today are very sensitive to be able to play the home burned CD's. On some of the older models, it is possible to force them to play the home burned CD disks, by going in there and doing a re-calibration of the player's alignment. In part of this recalibration, on purpose, the laser current may be able to be increased a bit. Specialized tools, training, and the service manual would be necessary to do this type of work. If the laser current is increased however, its life span will be shortened, because it was not designed to work at the higher intensity. I found that the blue reflective coloured media type CD disks were better for recording music to be played on standard CD players. I did some as long as 3 years ago, left them in the car all of the time (through winter and summer), and they still work very well. -- Greetings, Jerry Greenberg GLG Technologies GLG ========================================= WebPage http://www.zoom-one.com Electronics http://www.zoom-one.com/electron.htm ========================================= "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. -s |
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#8
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CD Quality Difference in Player
It has to do with the reflectivity of the CD media. The older players were
not too sensitive to the characteristics of the disks you would burn on your own burner. Most of the newer players manufactured today are very sensitive to be able to play the home burned CD's. On some of the older models, it is possible to force them to play the home burned CD disks, by going in there and doing a re-calibration of the player's alignment. In part of this recalibration, on purpose, the laser current may be able to be increased a bit. Specialized tools, training, and the service manual would be necessary to do this type of work. If the laser current is increased however, its life span will be shortened, because it was not designed to work at the higher intensity. I found that the blue reflective coloured media type CD disks were better for recording music to be played on standard CD players. I did some as long as 3 years ago, left them in the car all of the time (through winter and summer), and they still work very well. -- Greetings, Jerry Greenberg GLG Technologies GLG ========================================= WebPage http://www.zoom-one.com Electronics http://www.zoom-one.com/electron.htm ========================================= "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. -s |
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#9
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CD Quality Difference in Player
It has to do with the reflectivity of the CD media. The older players were
not too sensitive to the characteristics of the disks you would burn on your own burner. Most of the newer players manufactured today are very sensitive to be able to play the home burned CD's. On some of the older models, it is possible to force them to play the home burned CD disks, by going in there and doing a re-calibration of the player's alignment. In part of this recalibration, on purpose, the laser current may be able to be increased a bit. Specialized tools, training, and the service manual would be necessary to do this type of work. If the laser current is increased however, its life span will be shortened, because it was not designed to work at the higher intensity. I found that the blue reflective coloured media type CD disks were better for recording music to be played on standard CD players. I did some as long as 3 years ago, left them in the car all of the time (through winter and summer), and they still work very well. -- Greetings, Jerry Greenberg GLG Technologies GLG ========================================= WebPage http://www.zoom-one.com Electronics http://www.zoom-one.com/electron.htm ========================================= "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. -s |
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#10
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CD Quality Difference in Player
With VERY few exceptions, audio CD players do not calibrate laser power
automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#11
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CD Quality Difference in Player
With VERY few exceptions, audio CD players do not calibrate laser power
automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#12
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CD Quality Difference in Player
With VERY few exceptions, audio CD players do not calibrate laser power
automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#13
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CD Quality Difference in Player
With VERY few exceptions, audio CD players do not calibrate laser power
automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#14
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CD Quality Difference in Player
Surinder Singh wrote:
I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? No. it means your boom-box is crap quality. I have a Philips one like that too. It only ever plays CD-R up to about 5 minutes, if at all. geoff |
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#15
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CD Quality Difference in Player
Surinder Singh wrote:
I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? No. it means your boom-box is crap quality. I have a Philips one like that too. It only ever plays CD-R up to about 5 minutes, if at all. geoff |
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#16
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CD Quality Difference in Player
Surinder Singh wrote:
I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? No. it means your boom-box is crap quality. I have a Philips one like that too. It only ever plays CD-R up to about 5 minutes, if at all. geoff |
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#17
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CD Quality Difference in Player
Surinder Singh wrote:
I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? No. it means your boom-box is crap quality. I have a Philips one like that too. It only ever plays CD-R up to about 5 minutes, if at all. geoff |
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#18
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CD Quality Difference in Player
Sorry, Mark, I can't agree.
The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is .. Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#19
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CD Quality Difference in Player
Sorry, Mark, I can't agree.
The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is .. Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#20
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CD Quality Difference in Player
Sorry, Mark, I can't agree.
The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is .. Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#21
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CD Quality Difference in Player
Sorry, Mark, I can't agree.
The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is .. Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#22
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CD Quality Difference in Player
I was talking CD-R, not RW, haven't tried those in the older Sony's but I
would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#23
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CD Quality Difference in Player
I was talking CD-R, not RW, haven't tried those in the older Sony's but I
would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#24
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CD Quality Difference in Player
I was talking CD-R, not RW, haven't tried those in the older Sony's but I
would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#25
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CD Quality Difference in Player
I was talking CD-R, not RW, haven't tried those in the older Sony's but I
would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#26
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CD Quality Difference in Player
Robert Morein wrote: Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. My Denon I had ten years ago (bought new about 1992, IIRC) had no problems, either. It did have an "amplified" mode so that if the disc was reading poorly, it would basically double the sensitivity. Another way around the problem. Never ever had it fail to read a CD-R of any type. |
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#27
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CD Quality Difference in Player
Robert Morein wrote: Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. My Denon I had ten years ago (bought new about 1992, IIRC) had no problems, either. It did have an "amplified" mode so that if the disc was reading poorly, it would basically double the sensitivity. Another way around the problem. Never ever had it fail to read a CD-R of any type. |
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#28
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CD Quality Difference in Player
Robert Morein wrote: Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. My Denon I had ten years ago (bought new about 1992, IIRC) had no problems, either. It did have an "amplified" mode so that if the disc was reading poorly, it would basically double the sensitivity. Another way around the problem. Never ever had it fail to read a CD-R of any type. |
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#29
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CD Quality Difference in Player
Robert Morein wrote: Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. My Denon I had ten years ago (bought new about 1992, IIRC) had no problems, either. It did have an "amplified" mode so that if the disc was reading poorly, it would basically double the sensitivity. Another way around the problem. Never ever had it fail to read a CD-R of any type. |
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#30
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CD Quality Difference in Player
"Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#31
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CD Quality Difference in Player
"Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#32
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CD Quality Difference in Player
"Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#33
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CD Quality Difference in Player
"Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#34
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CD Quality Difference in Player
And yet the laser power is not calibrated according to any disc
reflectivity, merely to provide a constant laser current, which is virtually the same regardless of whether any laser light returns from the disc at all. In a multi-read model, which I will admit I have not studied, this may be different. Your old Sony however, isn't multi-read in the same sense as a modern CD-ROM device. It may just have the laser power turned up somewhat. The only unit I have seen which calibrated the laser output on playback was a karaoke model - unknown Chinese vendor. Viewing the HF pattern on a 'scope one could observe the laser "eye pattern" ramping up depending on the disc type. Your Sony does not do this. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#35
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CD Quality Difference in Player
And yet the laser power is not calibrated according to any disc
reflectivity, merely to provide a constant laser current, which is virtually the same regardless of whether any laser light returns from the disc at all. In a multi-read model, which I will admit I have not studied, this may be different. Your old Sony however, isn't multi-read in the same sense as a modern CD-ROM device. It may just have the laser power turned up somewhat. The only unit I have seen which calibrated the laser output on playback was a karaoke model - unknown Chinese vendor. Viewing the HF pattern on a 'scope one could observe the laser "eye pattern" ramping up depending on the disc type. Your Sony does not do this. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#36
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CD Quality Difference in Player
And yet the laser power is not calibrated according to any disc
reflectivity, merely to provide a constant laser current, which is virtually the same regardless of whether any laser light returns from the disc at all. In a multi-read model, which I will admit I have not studied, this may be different. Your old Sony however, isn't multi-read in the same sense as a modern CD-ROM device. It may just have the laser power turned up somewhat. The only unit I have seen which calibrated the laser output on playback was a karaoke model - unknown Chinese vendor. Viewing the HF pattern on a 'scope one could observe the laser "eye pattern" ramping up depending on the disc type. Your Sony does not do this. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#37
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CD Quality Difference in Player
And yet the laser power is not calibrated according to any disc
reflectivity, merely to provide a constant laser current, which is virtually the same regardless of whether any laser light returns from the disc at all. In a multi-read model, which I will admit I have not studied, this may be different. Your old Sony however, isn't multi-read in the same sense as a modern CD-ROM device. It may just have the laser power turned up somewhat. The only unit I have seen which calibrated the laser output on playback was a karaoke model - unknown Chinese vendor. Viewing the HF pattern on a 'scope one could observe the laser "eye pattern" ramping up depending on the disc type. Your Sony does not do this. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#38
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CD Quality Difference in Player
Please read my post again.
I said that AGC is a threshold detector function. It has nothing to do with laser diode power calibration. Sony players do nothing special with the laser diode. The AGC function provides variable threshold detection, which is what gives it the ability to read Orange Book. "Mark D. Zacharias" wrote in message ... And yet the laser power is not calibrated according to any disc reflectivity, merely to provide a constant laser current, which is virtually the same regardless of whether any laser light returns from the disc at all. In a multi-read model, which I will admit I have not studied, this may be different. Your old Sony however, isn't multi-read in the same sense as a modern CD-ROM device. It may just have the laser power turned up somewhat. The only unit I have seen which calibrated the laser output on playback was a karaoke model - unknown Chinese vendor. Viewing the HF pattern on a 'scope one could observe the laser "eye pattern" ramping up depending on the disc type. Your Sony does not do this. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#39
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CD Quality Difference in Player
Please read my post again.
I said that AGC is a threshold detector function. It has nothing to do with laser diode power calibration. Sony players do nothing special with the laser diode. The AGC function provides variable threshold detection, which is what gives it the ability to read Orange Book. "Mark D. Zacharias" wrote in message ... And yet the laser power is not calibrated according to any disc reflectivity, merely to provide a constant laser current, which is virtually the same regardless of whether any laser light returns from the disc at all. In a multi-read model, which I will admit I have not studied, this may be different. Your old Sony however, isn't multi-read in the same sense as a modern CD-ROM device. It may just have the laser power turned up somewhat. The only unit I have seen which calibrated the laser output on playback was a karaoke model - unknown Chinese vendor. Viewing the HF pattern on a 'scope one could observe the laser "eye pattern" ramping up depending on the disc type. Your Sony does not do this. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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#40
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CD Quality Difference in Player
Please read my post again.
I said that AGC is a threshold detector function. It has nothing to do with laser diode power calibration. Sony players do nothing special with the laser diode. The AGC function provides variable threshold detection, which is what gives it the ability to read Orange Book. "Mark D. Zacharias" wrote in message ... And yet the laser power is not calibrated according to any disc reflectivity, merely to provide a constant laser current, which is virtually the same regardless of whether any laser light returns from the disc at all. In a multi-read model, which I will admit I have not studied, this may be different. Your old Sony however, isn't multi-read in the same sense as a modern CD-ROM device. It may just have the laser power turned up somewhat. The only unit I have seen which calibrated the laser output on playback was a karaoke model - unknown Chinese vendor. Viewing the HF pattern on a 'scope one could observe the laser "eye pattern" ramping up depending on the disc type. Your Sony does not do this. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Mark D. Zacharias" wrote in message ... I was talking CD-R, not RW, haven't tried those in the older Sony's but I would be surprised. Lots of other units use the Sony pickups, and none of them boost the laser power based on reflectivity - a constant current is maintained as a voltage drop across a resistor, indicating a constant laser diode current, regardless of reflected signal received back to the diode pack. The APC (not ACG) transistor is mainly a switch, though as I say the current is kept nearly constant. Mark Z. I did not intend to imply that AGC is an adjustment of the laser diode. It is an adjustment of the threshold detector. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... Sorry, Mark, I can't agree. The following tech sheet http://www.sanyo.com/semiconductors/news/Vol66.pdf gives specs on the Sayn LA9251M, a common CD controller chip. Among the features provided is . Automatic follower operation (tracking gain and track detection level) Because lasers wear and output decays over time, calibration to the reflected signal at a particular point in the life in the product is essential. This feature is frequently referred to as AGC, and has been implemented with varying degrees of effectivenss in different players. For example, every Sony player I own, back to 1991, is multi-read capable, which means that it can read a CD-RW, which of all the available blanks differs the greatest from a pressing. Most other brands were, at least in the past, not nearly so good. It is remarkable that Sony built multi-read into their products long before CD-RW was in frequent use. I have the service manual for all my players, and none of these older, multiread capable units have either a calibration pot or a service mode. "Mark D. Zacharias" wrote in message ... With VERY few exceptions, audio CD players do not calibrate laser power automatically. Some are adjusted with physical potentiometers, some newer ones do it in a service mode using eeproms, but once set, the laser calibration is done. Focus is adjusted dynamically while playing, and of course during the focus search routine. Focus offset value is kept in memory until the next disc read operation so that if the PLAY button is pressed again, it can spin immediately without doing another focus search. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Robert Morein" wrote in message ... "Surinder Singh" wrote in message ... I play the CD's I burn in Phillipps Boombox. If I Maxell Gold CD-R it takes 20 seconds for the boom box to recognize the tracks and be ready to play it after inserting the CD. With Memorex 52x, it takes only 2 seconds for boom to recognize the tracks. Does it mean that Memorex is better quality? I would have thought the gold coloration ;-) & Maxell name would make the former a better quality? Thanks. Different CD disks have different reflectivities for the burn/no burn conditions. The CD player has a calibration function that enables it to correctly recognize these conditions. Depending upon the design of the player, the ability to recognize disks with different reflectivities vary. Only a few years ago, it was common for many brands of CD players to fail to recognize CD-Rs, because insufficient range had been built into the calibration function. What you observe has more to do with the player than the disk. Gold as a reflective material has a signficant advantage for archival use. However, it is somewhat less reflective than aluminum. |
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