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#1
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
The mythology that direct drive turntables are inherently
prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. Some misapprehensions about so-called direct drive turntables trace back to the terminology "Direct Drive". A more detailed understanding of how direct drive turntables work reveals that the so-called direct drive turntable's platter is not driven directly, but that the rotational drive is applied through a varying magnetic field. This magnetic field replaces the traditional rubber belt or wheel as the flexible means by which the turntable is driven. Two disadvantages of drive through rubber belts or wheels is that the compliance, stiffness or flexibility of a rubber wheel or belt is constant in the short term, and degrades over the long term as the elastic parts wear and/or stiffen. Rubber and other elastomers tend to harden over time, and crack finally demanding replacement. In contrast, magnetic fields are constantly being replenished by the control system, and do not themselves necessarily degrade over time like flexible belts and wheels. The stiffness of a turntable's drive relates to how well the rotating mass of the platter filters out speed variations. A drive that is less stiff leads to better filtration. A highly flexible drive can be traded off with the mass of the turntable. The filtering action is based on the combination of a high-mass platter and a highly flexible drive. If you increase the mass and stiffen the drive the filtering action remains constant. If you make the drive more flexible or increase the mass, the filtering action improves. However, it is not practical to make a turntable with an extremely flexible belt or wheel drive because it would take forever to come up to speed. Ideally, we'd like to have a belt that is stiff for fast starts, and highly flexible for smooth running. But rubber belts and wheels can't adapt to changing needs. They are what they are that day. A major highly desirable property of a direct drive turntables' magnetic field drive is that the stiffness of the drive can be varied rapidly by its electronic control system. This contrasts with a rubber wheel or belt whose stiffness remains the same as you start, run and stop the turntable. A rubber belt's stiffness must be compromised because it can't adapt to changing needs. The stiffness of a magnetic drive can change rapidly and automatically to meet changing needs. A magnetic field drive based on an internal speed sensor naturally simulates a stiff belt when the turntable is starting up, and then automatically and naturally changes over to something like a very stretchy rubber belt, when the turntable is running normally. If you use your finger to drag a direct drive turntable to a stop, you may feel the control system pushing harder, perhaps even pulsing. This does not mean that it is pulsing significantly when the turntable is running normally. The measure of the constant speed of a turntable should be reliably determined by bias-controlled listening tests and standard technical measures for speed consistency, not behavior under unusual operating conditions. There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. |
#2
Posted to rec.audio.opinion
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More invalid simplifications
"Arny Krueger" wrote in message ... The mythology that direct drive turntables are inherently prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. Some misapprehensions about so-called direct drive turntables trace back to the terminology "Direct Drive". A more detailed understanding of how direct drive turntables work reveals that the so-called direct drive turntable's platter is not driven directly, but that the rotational drive is applied through a varying magnetic field. This magnetic field replaces the traditional rubber belt or wheel as the flexible means by which the turntable is driven. Crugly spoken, but partially true. There are details associated with each method that also have a bearing [sic]. Recently, I asked Arny to clarify about what he calls "magnetic coupling", and he responded, as usual, with a gratuitous insult. Here he has inadvertently answered the question, making it clear that he is referring to the magnetic field inside the motor. That a driving magnetic field does not provide acoustic isolation is easily demonstrated in one device with which we are all familiar, namely, the dynamic loudspeaker. Whether the field in a motor creates a disturbance audible at the stylus is a function of driving method. Pulse modulation of the motor drive has a minimum power, depending upon the circuitry used. No motor can function at zero drive. Therefore, some modulation is always present at the driving frequency. Certain geometric/phase arrangments produce constant driving torque, but there is a 2nd order effect that works against this. Any variation in the motor from completely symmetric internal geometry will cause a cyclic variation in torque. Any winding variation, or asymmetry of the driving circuitry, will cause a cyclic torque. These are potential problems with the direct drive arrangement. The belt drive virtually guarantees that rotational defects will be limited to low frequency artifacts. Belt drive permits optimization of the platter support, in the form of simplified bearings, less likely to cause mechanical noise than the ball or fluid dynamic bearings used in motors. All bearings have, by their nature, a minimum clearance, which permits a disturbance in motor geometry, as described above. These are potential pitfalls. I do not mean to say that either type of implementation is invariably superior. But since one cannot be guided, by the type, to the superior choice, the actual performance of the turntable must be evaluated by testing. I would suggest it's pointless for rao'ers to beat each other over the head regarding the internals, as opposed to the result. |
#3
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"Arny Krueger" wrote in message ... The mythology that direct drive turntables are inherently prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. Some misapprehensions about so-called direct drive turntables trace back to the terminology "Direct Drive". A more detailed understanding of how direct drive turntables work reveals that the so-called direct drive turntable's platter is not driven directly, but that the rotational drive is applied through a varying magnetic field. This magnetic field replaces the traditional rubber belt or wheel as the flexible means by which the turntable is driven. Two disadvantages of drive through rubber belts or wheels is that the compliance, stiffness or flexibility of a rubber wheel or belt is constant in the short term, and degrades over the long term as the elastic parts wear and/or stiffen. Rubber and other elastomers tend to harden over time, and crack finally demanding replacement. In contrast, magnetic fields are constantly being replenished by the control system, and do not themselves necessarily degrade over time like flexible belts and wheels. The stiffness of a turntable's drive relates to how well the rotating mass of the platter filters out speed variations. A drive that is less stiff leads to better filtration. A highly flexible drive can be traded off with the mass of the turntable. The filtering action is based on the combination of a high-mass platter and a highly flexible drive. If you increase the mass and stiffen the drive the filtering action remains constant. If you make the drive more flexible or increase the mass, the filtering action improves. However, it is not practical to make a turntable with an extremely flexible belt or wheel drive because it would take forever to come up to speed. Ideally, we'd like to have a belt that is stiff for fast starts, and highly flexible for smooth running. But rubber belts and wheels can't adapt to changing needs. They are what they are that day. A major highly desirable property of a direct drive turntables' magnetic field drive is that the stiffness of the drive can be varied rapidly by its electronic control system. This contrasts with a rubber wheel or belt whose stiffness remains the same as you start, run and stop the turntable. A rubber belt's stiffness must be compromised because it can't adapt to changing needs. The stiffness of a magnetic drive can change rapidly and automatically to meet changing needs. A magnetic field drive based on an internal speed sensor naturally simulates a stiff belt when the turntable is starting up, and then automatically and naturally changes over to something like a very stretchy rubber belt, when the turntable is running normally. If you use your finger to drag a direct drive turntable to a stop, you may feel the control system pushing harder, perhaps even pulsing. This does not mean that it is pulsing significantly when the turntable is running normally. The measure of the constant speed of a turntable should be reliably determined by bias-controlled listening tests and standard technical measures for speed consistency, not behavior under unusual operating conditions. There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Way to far over the heads of the faithful. :-) |
#4
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
In article ,
"Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? Stephen |
#5
Posted to rec.audio.opinion
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More invalid simplifications
"Robert Morein" wrote in message
That a driving magnetic field does not provide acoustic isolation is easily demonstrated in one device with which we are all familiar, namely, the dynamic loudspeaker. As usual Morein is working overtime trying to create new fallacies as quickly as I spike the old ones. Here Morein purpounds the fallacy that all magnetic fields are the same. In fact they differ in a number of areas, most significantly being strength. Whether the field in a motor creates a disturbance audible at the stylus is a function of driving method. This statement ignores the fact that many system parameters are more important than the driving method. For example, the driving method in any modern turntable is identically the same - a magnetic field in an electric motor. It's the differences in the other system parameters that makes a belt drive system different from a so-called direct drive system. Pulse modulation of the motor drive has a minimum power, depending upon the circuitry used. In fact pulse modulation is used on both direct drive and also some belt drive turntables. Therefore the introduction of pulse modulation is a straw man argument and can be safely ignored. No motor can function at zero drive. I never said that they did. So this would be the second straw man argument in the same paragraph. Therefore, some modulation is always present at the driving frequency. Here the classic error of ignoring quantification is made. Certain geometric/phase arrangments produce constant driving torque, but there is a 2nd order effect that works against this. Again this applies to both belt drives and so-called direct drives so we now have our third straw man argument. Any variation in the motor from completely symmetric internal geometry will cause a cyclic variation in torque. Any winding variation, or asymmetry of the driving circuitry, will cause a cyclic torque. This again applies to both belt drives and so-called direct drives so we now have our fourth straw man argument. These are potential problems with the direct drive arrangement. Every problem listed so far applies to both belt drive and direct drive systems. The belt drive virtually guarantees that rotational defects will be limited to low frequency artifacts. The presence of a belt is not a panacea. The time-honored open-loop motor driving a rubber belt suffers from a number of problems related to operational parameters that can't change when the operational mode changes from start-up to normal rotation. Belt drive permits optimization of the platter support, Direct drive provides more options. Since direct-drive motors run at a far slower speed than belt-drive motors, natural vibration modes are not in the audio range. For example a belt-drive motor might have 24 poles and turn at 300 rpm. This results in 7200 noise impulses per minute, which corresponds to a noise at 120 Hz. in the form of simplified bearings, less likely to cause mechanical noise than the ball or fluid dynamic bearings used in motors. In fact platter bearings in direct drive turntables can be identical to platter bearings in belt-drive turntables. This comment by Morein is no doubt based on his inability to actually examine a number of direct-drive turntables due to his confinement. All bearings have, by their nature, a minimum clearance, which permits a disturbance in motor geometry, as described above. Just another item that is common to both direct-drive and belt-drive designs. This makes Morein's fifth straw man argument in just one post. These are potential pitfalls. I do not mean to say that either type of implementation is invariably superior. But since one cannot be guided, by the type, to the superior choice, the actual performance of the turntable must be evaluated by testing. I would suggest it's pointless for rao'ers to beat each other over the head regarding the internals, as opposed to the result. Notice that my post mentioned no names, so there was no "beating" involved. OTOH, Morein gratuitously mentioned my name in a negative context that went well beyond simply quoting my post. I think that Morien's bad faith should be obvious to all. |
#6
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
wrote in message
nk.net "Arny Krueger" wrote in message ... The mythology that direct drive turntables are inherently prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. Some misapprehensions about so-called direct drive turntables trace back to the terminology "Direct Drive". A more detailed understanding of how direct drive turntables work reveals that the so-called direct drive turntable's platter is not driven directly, but that the rotational drive is applied through a varying magnetic field. This magnetic field replaces the traditional rubber belt or wheel as the flexible means by which the turntable is driven. Two disadvantages of drive through rubber belts or wheels is that the compliance, stiffness or flexibility of a rubber wheel or belt is constant in the short term, and degrades over the long term as the elastic parts wear and/or stiffen. Rubber and other elastomers tend to harden over time, and crack finally demanding replacement. In contrast, magnetic fields are constantly being replenished by the control system, and do not themselves necessarily degrade over time like flexible belts and wheels. The stiffness of a turntable's drive relates to how well the rotating mass of the platter filters out speed variations. A drive that is less stiff leads to better filtration. A highly flexible drive can be traded off with the mass of the turntable. The filtering action is based on the combination of a high-mass platter and a highly flexible drive. If you increase the mass and stiffen the drive the filtering action remains constant. If you make the drive more flexible or increase the mass, the filtering action improves. However, it is not practical to make a turntable with an extremely flexible belt or wheel drive because it would take forever to come up to speed. Ideally, we'd like to have a belt that is stiff for fast starts, and highly flexible for smooth running. But rubber belts and wheels can't adapt to changing needs. They are what they are that day. A major highly desirable property of a direct drive turntables' magnetic field drive is that the stiffness of the drive can be varied rapidly by its electronic control system. This contrasts with a rubber wheel or belt whose stiffness remains the same as you start, run and stop the turntable. A rubber belt's stiffness must be compromised because it can't adapt to changing needs. The stiffness of a magnetic drive can change rapidly and automatically to meet changing needs. A magnetic field drive based on an internal speed sensor naturally simulates a stiff belt when the turntable is starting up, and then automatically and naturally changes over to something like a very stretchy rubber belt, when the turntable is running normally. If you use your finger to drag a direct drive turntable to a stop, you may feel the control system pushing harder, perhaps even pulsing. This does not mean that it is pulsing significantly when the turntable is running normally. The measure of the constant speed of a turntable should be reliably determined by bias-controlled listening tests and standard technical measures for speed consistency, not behavior under unusual operating conditions. There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Way to far over the heads of the faithful. :-) Morein has already demonstrated that, and again showed bad faith by gratuitous inclusion of a personal attack on me. His continuted devotion to the debating trade was shown by no less than 5 straw man arguments. |
#7
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"MINe 109" wrote in message
In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives If you don't think its broken, don't try to fix it. because someone might someday market a direct-drive that fulfills this potential? Please explain why you think that this is so? |
#8
Posted to rec.audio.opinion
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More invalid simplifications
"Arny Krueger" wrote in message ... "Robert Morein" wrote in message That a driving magnetic field does not provide acoustic isolation is easily demonstrated in one device with which we are all familiar, namely, the dynamic loudspeaker. As usual Morein is working overtime trying to create new fallacies as quickly as I spike the old ones. Arny's reply is shallow, deceitful, and unworthy of reply. |
#9
Posted to rec.audio.opinion
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More invalid simplifications
"Robert Morein" wrote in message
"Arny Krueger" wrote in message ... "Robert Morein" wrote in message That a driving magnetic field does not provide acoustic isolation is easily demonstrated in one device with which we are all familiar, namely, the dynamic loudspeaker. As usual Morein is working overtime trying to create new fallacies as quickly as I spike the old ones. Arny's reply is shallow, deceitful, and unworthy of reply. But Robert, being desperate to appear to have said something with substance, posted a reply anyway. It was even more lacking in substance than the first . :-( |
#10
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"MINe 109" wrote in message ... In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? Stephen Don't expect an answer. Arny's brain just received the order "Take evasive action!" |
#11
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"Robert Morein" wrote in message
"MINe 109" wrote in message ... In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? Stephen Don't expect an answer. Arny's brain just received the order "Take evasive Robert, I cleverly posted an answer 8 minutes before you made this post. Let's hear it for the usual time delays in Usenet and your ignorance of them. action!" |
#12
Posted to rec.audio.opinion
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More invalid simplifications
"Arny Krueger" wrote in message ... "Robert Morein" wrote in message "Arny Krueger" wrote in message ... "Robert Morein" wrote in message That a driving magnetic field does not provide acoustic isolation is easily demonstrated in one device with which we are all familiar, namely, the dynamic loudspeaker. As usual Morein is working overtime trying to create new fallacies as quickly as I spike the old ones. Arny's reply is shallow, deceitful, and unworthy of reply. But Robert, being desperate to appear to have said something with substance, posted a reply anyway. It was even more lacking in substance than the first . :-( Alright, here's a reply. You cannot PROVE that one type is better than the other. Either design can be executed with a varying degree of precision and competence. All the points that you mentioned, for a particular case, can be either correct or incorrect. I think that as a designer, I would prefer to do a direct drive design. But neither of us has the hands-on experience of the world's great turntable makers. Therefore, a design can be judged only by the performance, not the ingredients. I am amazed that you rose to the effort you did to negate Bret's troll. Bret's post was obviously a troll, because it was a sloppy job. I'm sure he had a lot of fun doing it. But you, in all seriousness, put a lot of work into your post, trying to nail down "facts" about these two approaches that are not facts, but merely factors, that the designer has to deal with. Factors add and multiply cumulatively in a design, frequently leading to consequences that cannot be anticipated by examining them in isolation. |
#13
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"Arny Krueger" wrote in message ... "Robert Morein" wrote in message "MINe 109" wrote in message ... In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? Stephen Don't expect an answer. Arny's brain just received the order "Take evasive Robert, I cleverly posted an answer 8 minutes before you made this post. Let's hear it for the usual time delays in Usenet and your ignorance of them. action!" It was exactly what I anticipated -- an evasion. |
#14
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
MINe 109 wrote: In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? You imply there hasn't been plethora of DD turntables that already fullfill this mark. I think both DD and belt drive technologies have been able to push platter rumble and speed variations (wow and flutter) well below record noise. DD has a couple advantages IMO. Its lower maintenance than belt but more importantly has greater torque which makes it a lot easier to use a record brush to remove surface dust before playing. I wish someone could supply truly dust free record sleeves. I had some VPI record protectors which are zip lock plastic bags but getting the record into the barely large enough opening is a PITA. They've become embrittled over time and I had to replace them. I bought a bunch of rice paper sleeves and plastic lined sleeves in bulk and both are pretty dusty. I can put a perfectly clean record into the sleeve and pull it out immediately with a bit o dust on it. I hit every record with a brush before playing and the DD tables make this alot easier than my old AR-XA which had so little torque any pressure from the brush brought the platter to a halt. The other advantage is that 45 to 33 speed changes are a push of a button. Most belts need at least a change of pulley position. ScottW |
#15
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"Arny Krueger" wrote in message . .. wrote in message nk.net "Arny Krueger" wrote in message ... The mythology that direct drive turntables are inherently prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. Some misapprehensions about so-called direct drive turntables trace back to the terminology "Direct Drive". A more detailed understanding of how direct drive turntables work reveals that the so-called direct drive turntable's platter is not driven directly, but that the rotational drive is applied through a varying magnetic field. This magnetic field replaces the traditional rubber belt or wheel as the flexible means by which the turntable is driven. Two disadvantages of drive through rubber belts or wheels is that the compliance, stiffness or flexibility of a rubber wheel or belt is constant in the short term, and degrades over the long term as the elastic parts wear and/or stiffen. Rubber and other elastomers tend to harden over time, and crack finally demanding replacement. In contrast, magnetic fields are constantly being replenished by the control system, and do not themselves necessarily degrade over time like flexible belts and wheels. The stiffness of a turntable's drive relates to how well the rotating mass of the platter filters out speed variations. A drive that is less stiff leads to better filtration. A highly flexible drive can be traded off with the mass of the turntable. The filtering action is based on the combination of a high-mass platter and a highly flexible drive. If you increase the mass and stiffen the drive the filtering action remains constant. If you make the drive more flexible or increase the mass, the filtering action improves. However, it is not practical to make a turntable with an extremely flexible belt or wheel drive because it would take forever to come up to speed. Ideally, we'd like to have a belt that is stiff for fast starts, and highly flexible for smooth running. But rubber belts and wheels can't adapt to changing needs. They are what they are that day. A major highly desirable property of a direct drive turntables' magnetic field drive is that the stiffness of the drive can be varied rapidly by its electronic control system. This contrasts with a rubber wheel or belt whose stiffness remains the same as you start, run and stop the turntable. A rubber belt's stiffness must be compromised because it can't adapt to changing needs. The stiffness of a magnetic drive can change rapidly and automatically to meet changing needs. A magnetic field drive based on an internal speed sensor naturally simulates a stiff belt when the turntable is starting up, and then automatically and naturally changes over to something like a very stretchy rubber belt, when the turntable is running normally. If you use your finger to drag a direct drive turntable to a stop, you may feel the control system pushing harder, perhaps even pulsing. This does not mean that it is pulsing significantly when the turntable is running normally. The measure of the constant speed of a turntable should be reliably determined by bias-controlled listening tests and standard technical measures for speed consistency, not behavior under unusual operating conditions. There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Way to far over the heads of the faithful. :-) Morein has already demonstrated that, and again showed bad faith by gratuitous inclusion of a personal attack on me. His continuted devotion to the debating trade was shown by no less than 5 straw man arguments. I killfiled him, his posts are almost always pointless and when he does try to wax technical, he usually gets it wrong either by ignorance or deleiberate distortion of the facts. He's a waste of time. |
#16
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"MINe 109" wrote in message ... In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? I think that you should keep whatever functioning table you have until it no longer reasonable to do so. When it comes time for a new table get a proper Direct Drive. |
#17
Posted to rec.audio.opinion
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More invalid simplifications
"Robert Morein" wrote in message
You cannot PROVE that one type is better than the other. Either can be well-executed or poorly executed. Either can be good enough. However, direct drive has a lot of real-world advantages: (1) No belt to stretch, crack or fall off the pulley. I've had all 3 nasties happen to me with one or the other of the 3 belt-drive turntables that I have owned. (2) Quick start. (3) While belt drive can be good enough, direct drive has the greatest potential for ultimate performance for the reasons I've now had to go over several times. Either design can be executed with a varying degree of precision and competence. Dooh! All the points that you mentioned, for a particular case, can be either correct or incorrect. Dooh! I think that as a designer, I would prefer to do a direct drive design. Robert, given your demonstrated engineering savvy, I concur. Any semi-competent basement mechanic can make a workable belt-drive turntable drive system. A direct drive system requires competence with electronic control systems, for example. But neither of us has the hands-on experience of the world's great turntable makers. Well there you go, Robert's sixth straw man of the day. Therefore, a design can be judged only by the performance, not the ingredients. Well if you want it to be reliable and perform as well as possible, then the choice is clear - drop your belts! |
#18
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
On Mon, 05 Dec 2005 16:45:48 GMT, wrote:
That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Way to far over the heads of the faithful. :-) Which is why Arnold uses a 15+ year old belt-drive turntable, when he could have gotten a new direct drive turntable for about the same amount of money. |
#19
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
dave weil said: Way to[sic] far over the heads of the faithful. :-) Which is why Arnold uses a 15+ year old belt-drive turntable, when he could have gotten a new direct drive turntable for about the same amount of money. If you could beg borrow, or, steal a clue Mr. Wiel then, you would know there is a big difference between an audiophool and a Engineer. Its like some audiophool who subscribe's to Stereopile would gladly pay 1000's of dollar's for a turn table when, its an inferrier media anyway. Thanks Mr. Wile for admitting you prefer an infeerior technology. LOL! ;-) |
#20
Posted to rec.audio.opinion
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Arny drops his pants
"Arny Krueger" wrote in message ... "Robert Morein" wrote in message You cannot PROVE that one type is better than the other. [snip] Dooh! [snip] Dooh! [snip] Well if you want it to be reliable and perform as well as possible, then the choice is clear - drop your belts! Arny, do the world a favor. Keep your belt on tight. |
#21
Posted to rec.audio.opinion
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Idler drive: the superior alternative
"ScottW" wrote in message ups.com... MINe 109 wrote: In article , [snip] You imply there hasn't been plethora of DD turntables that already fullfill this mark. I think both DD and belt drive technologies have been able to push platter rumble and speed variations (wow and flutter) well below record noise. DD has a couple advantages IMO. Its lower maintenance than belt but more importantly has greater torque which makes it a lot easier to use a record brush to remove surface dust before playing. I wish someone could supply truly dust free record sleeves. I had some VPI record protectors which are zip lock plastic bags but getting the record into the barely large enough opening is a PITA. They've become embrittled over time and I had to replace them. I bought a bunch of rice paper sleeves and plastic lined sleeves in bulk and both are pretty dusty. I can put a perfectly clean record into the sleeve and pull it out immediately with a bit o dust on it. I hit every record with a brush before playing and the DD tables make this alot easier than my old AR-XA which had so little torque any pressure from the brush brought the platter to a halt. Compare to idler drive, with inherently high torque and fast start. The other advantage is that 45 to 33 speed changes are a push of a button. Most belts need at least a change of pulley position. ScottW Another advantage of idler drive turntables. Speed can be changed by a simple mechanical switch, avoiding the overcomplex approach of the other two designs. Additionally, idler designs driven by a synchronous motor are inherently more reliable that electronic motors, all of which incorporate tantalum capacitors, each of which has a failure rate of about 1% per year. |
#22
Posted to rec.audio.opinion
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More invalid simplifications
Arny Krueger wrote: "Robert Morein" wrote in message You cannot PROVE that one type is better than the other. Either can be well-executed or poorly executed. Either can be good enough. However, direct drive has a lot of real-world advantages: (1) No belt to stretch, crack or fall off the pulley. I've had all 3 nasties happen to me with one or the other of the 3 belt-drive turntables that I have owned. Belts are cheap. A new design might even use 0-rings or even mag tape as a belt. (2) Quick start. Important, for DJs. That's why DJ tables are direct drive. Not so for audiophiles. (3) While belt drive can be good enough, direct drive has the greatest potential for ultimate performance for the reasons I've now had to go over several times. Either design can be executed with a varying degree of precision and competence. Dooh! All the points that you mentioned, for a particular case, can be either correct or incorrect. Dooh! I think that as a designer, I would prefer to do a direct drive design. Robert, given your demonstrated engineering savvy, I concur. Any semi-competent basement mechanic can make a workable belt-drive turntable drive system. A direct drive system requires competence with electronic control systems, for example. Solutions a basement mechanic could build are intrinsically more sustainable than those requiring substantial interdisciplinary expertise. Legend has it that B.D. Maule and Kelly Johnson were introduced at some aviation function as "great airplane designers". Now B.D. was a basement mechanic whose airplane was essentially a homebuilt Piper Pacer. Johnson was polite, but later made a Bacall/Kidman-like remark about the tube-and rag taildragger vendor to one of the Lockheed test pilots (I think it was Salmon or LeVier). Whoever it was, told Johnson that fifty years after the last Blackbird had made its final flight, Maules would still be flying. Good belt drive tables are at least as good as any direct drive table and far cheaper to implement, and in practice are more likely to excel, sonically, than direct drive. OTOH direct drive tables are more satisfactory for DJing and "scratching". Just as a QSC PA amp will never really sound better when connected to efficient speakers in a house than a well-built tube amp, a Technics SL1200 will never equal a Merrill-modified AR or the admittedly overpriced Linn for sonics. |
#23
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
In article et,
wrote: "Arny Krueger" wrote in message ... The mythology that direct drive turntables are inherently prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. Some misapprehensions about so-called direct drive turntables trace back to the terminology "Direct Drive". A more detailed understanding of how direct drive turntables work reveals that the so-called direct drive turntable's platter is not driven directly, but that the rotational drive is applied through a varying magnetic field. This magnetic field replaces the traditional rubber belt or wheel as the flexible means by which the turntable is driven. Two disadvantages of drive through rubber belts or wheels is that the compliance, stiffness or flexibility of a rubber wheel or belt is constant in the short term, and degrades over the long term as the elastic parts wear and/or stiffen. Rubber and other elastomers tend to harden over time, and crack finally demanding replacement. In contrast, magnetic fields are constantly being replenished by the control system, and do not themselves necessarily degrade over time like flexible belts and wheels. The stiffness of a turntable's drive relates to how well the rotating mass of the platter filters out speed variations. A drive that is less stiff leads to better filtration. A highly flexible drive can be traded off with the mass of the turntable. The filtering action is based on the combination of a high-mass platter and a highly flexible drive. If you increase the mass and stiffen the drive the filtering action remains constant. If you make the drive more flexible or increase the mass, the filtering action improves. However, it is not practical to make a turntable with an extremely flexible belt or wheel drive because it would take forever to come up to speed. Ideally, we'd like to have a belt that is stiff for fast starts, and highly flexible for smooth running. But rubber belts and wheels can't adapt to changing needs. They are what they are that day. A major highly desirable property of a direct drive turntables' magnetic field drive is that the stiffness of the drive can be varied rapidly by its electronic control system. This contrasts with a rubber wheel or belt whose stiffness remains the same as you start, run and stop the turntable. A rubber belt's stiffness must be compromised because it can't adapt to changing needs. The stiffness of a magnetic drive can change rapidly and automatically to meet changing needs. A magnetic field drive based on an internal speed sensor naturally simulates a stiff belt when the turntable is starting up, and then automatically and naturally changes over to something like a very stretchy rubber belt, when the turntable is running normally. If you use your finger to drag a direct drive turntable to a stop, you may feel the control system pushing harder, perhaps even pulsing. This does not mean that it is pulsing significantly when the turntable is running normally. The measure of the constant speed of a turntable should be reliably determined by bias-controlled listening tests and standard technical measures for speed consistency, not behavior under unusual operating conditions. There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Way to far over the heads of the faithful. :-) Kind of like spelling? |
#24
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
In article . com,
"ScottW" wrote: MINe 109 wrote: In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? You imply there hasn't been plethora of DD turntables that already fullfill this mark. I think both DD and belt drive technologies have been able to push platter rumble and speed variations (wow and flutter) well below record noise. DD has a couple advantages IMO. Its lower maintenance than belt but more importantly has greater torque which makes it a lot easier to use a record brush to remove surface dust before playing. I sure have no trouble using a brush with my belt drive. And the platter is up to speed in about 4 seconds. I wish someone could supply truly dust free record sleeves. I had some VPI record protectors which are zip lock plastic bags but getting the record into the barely large enough opening is a PITA. They've become embrittled over time and I had to replace them. I bought a bunch of rice paper sleeves and plastic lined sleeves in bulk and both are pretty dusty. I can put a perfectly clean record into the sleeve and pull it out immediately with a bit o dust on it. I hit every record with a brush before playing and the DD tables make this alot easier than my old AR-XA which had so little torque any pressure from the brush brought the platter to a halt. The other advantage is that 45 to 33 speed changes are a push of a button. Most belts need at least a change of pulley position. ScottW |
#25
Posted to rec.audio.opinion
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More invalid simplifications
In article om,
"Bret Ludwig" wrote: Arny Krueger wrote: "Robert Morein" wrote in message You cannot PROVE that one type is better than the other. Either can be well-executed or poorly executed. Either can be good enough. However, direct drive has a lot of real-world advantages: (1) No belt to stretch, crack or fall off the pulley. I've had all 3 nasties happen to me with one or the other of the 3 belt-drive turntables that I have owned. Belts are cheap. A new design might even use 0-rings or even mag tape as a belt. There is at least one present design that uses mag tape. |
#26
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
In article . com,
"ScottW" wrote: MINe 109 wrote: In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? You imply there hasn't been plethora of DD turntables that already fullfill this mark. Rockport, a coupla Technics and Denons, but I think Arny set the bar higher than the last two. I think both DD and belt drive technologies have been able to push platter rumble and speed variations (wow and flutter) well below record noise. DD has a couple advantages IMO. Its lower maintenance than belt but more importantly has greater torque which makes it a lot easier to use a record brush to remove surface dust before playing. Which is it: both types are functional or direct-drive has fulfilled its "greater potential"? I wish someone could supply truly dust free record sleeves. I had some VPI record protectors which are zip lock plastic bags but getting the record into the barely large enough opening is a PITA. They've become embrittled over time and I had to replace them. I bought a bunch of rice paper sleeves and plastic lined sleeves in bulk and both are pretty dusty. I can put a perfectly clean record into the sleeve and pull it out immediately with a bit o dust on it. I hit every record with a brush before playing and the DD tables make this alot easier than my old AR-XA which had so little torque any pressure from the brush brought the platter to a halt. Not to mention the cool retrograde mode. The other advantage is that 45 to 33 speed changes are a push of a button. Most belts need at least a change of pulley position. Yep. I prefer separate decks for 45 and 33 in stereo and mono, and for 78 rpm. Well, I would... Stephen |
#27
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
In article ,
"Arny Krueger" wrote: "MINe 109" wrote in message In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives If you don't think its broken, don't try to fix it. because someone might someday market a direct-drive that fulfills this potential? Please explain why you think that this is so? Some myth-busting: direct-drive has greater potential, but there aren't any products. Stephen |
#28
Posted to rec.audio.opinion
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More invalid simplifications
"Bret Ludwig" wrote in message ps.com... Arny Krueger wrote: "Robert Morein" wrote in message You cannot PROVE that one type is better than the other. Either can be well-executed or poorly executed. Either can be good enough. However, direct drive has a lot of real-world advantages: (1) No belt to stretch, crack or fall off the pulley. I've had all 3 nasties happen to me with one or the other of the 3 belt-drive turntables that I have owned. Belts are cheap. A new design might even use 0-rings or even mag tape as a belt. (2) Quick start. Important, for DJs. That's why DJ tables are direct drive. Not so for audiophiles. (3) While belt drive can be good enough, direct drive has the greatest potential for ultimate performance for the reasons I've now had to go over several times. Either design can be executed with a varying degree of precision and competence. Dooh! All the points that you mentioned, for a particular case, can be either correct or incorrect. Dooh! I think that as a designer, I would prefer to do a direct drive design. Robert, given your demonstrated engineering savvy, I concur. Any semi-competent basement mechanic can make a workable belt-drive turntable drive system. A direct drive system requires competence with electronic control systems, for example. Solutions a basement mechanic could build are intrinsically more sustainable than those requiring substantial interdisciplinary expertise. snip of irrelvant airplane stuff. Good belt drive tables are at least as good as any direct drive table and far cheaper to implement, and in practice are more likely to excel, sonically, than direct drive. The least speed deviation is from Direct drive turntables. OTOH direct drive tables are more satisfactory for DJing and "scratching". They are more reliable, they don't require a belt replacement ever, when done with a modicum of precision, they are easily better than belt drive tables no matter what the mythology of the high end says. Just as a QSC PA amp will never really sound better when connected to efficient speakers in a house than a well-built tube amp, a Technics SL1200 will never equal a Merrill-modified AR or the admittedly overpriced Linn for sonics. Just keep making it up as you go along. If you ever find any actual evidence to prove any of your points we'll all be surpised, instead you make sweeping statements that simply don't fit the facts as known. Just becuase you find somebody else who agrees with you doesn't make you right. If precision is what the LP lover wants the LP lover wants a direct drive table. |
#29
Posted to rec.audio.opinion
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More invalid simplifications
"Bret Ludwig" wrote in message ps.com... Good belt drive tables are at least as good as any direct drive table and far cheaper to implement, Sure, rubber bands are cheap. and in practice are more likely to excel, Proof? sonically, than direct drive. I didn't think so. OTOH direct drive tables are more satisfactory for DJing and "scratching". Just as a QSC PA amp will never really sound better when connected to efficient speakers in a house than a well-built tube amp, I don't suppose you even A/B'd the QSC against some other SS amp, or did you? And it's a certainty that you did no DBT to see if you really hear a difference instead of working from your overactive imaginiation. LOL. That's a prefernce but the fact is still that any decent and that's most of them, SS amp can run circles around a tube amp in terms of accuracy. If you want tube sound stick a 1 ohm resistor in line with the speakers. a Technics SL1200 will never equal a Merrill-modified AR or the admittedly overpriced Linn for sonics. POut a decent arm on the Technics and a better bass and you have a turntable that will be more accurate than any rubber band driven gizmo. |
#30
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
On Mon, 05 Dec 2005 18:54:25 GMT, wrote:
Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? I think that you should keep whatever functioning table you have until it no longer reasonable to do so. When it comes time for a new table get a proper Direct Drive. Or, heaven forbid, a CD player. |
#31
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"MINe 109" wrote in message
In article , "Arny Krueger" wrote: "MINe 109" wrote in message In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives If you don't think its broken, don't try to fix it. because someone might someday market a direct-drive that fulfills this potential? Please explain why you think that this is so? Some myth-busting: direct-drive has greater potential, but there aren't any products. There aren't any direct-drive products????? |
#32
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
In article ,
"Arny Krueger" wrote: "MINe 109" wrote in message In article , "Arny Krueger" wrote: "MINe 109" wrote in message In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives If you don't think its broken, don't try to fix it. because someone might someday market a direct-drive that fulfills this potential? Please explain why you think that this is so? Some myth-busting: direct-drive has greater potential, but there aren't any products. There aren't any direct-drive products????? That "provide [more] excellent, long-lasting high performance than a belt drive"? Existing good direct-drives are roughly equivalent to good belt-drives. Stephen |
#33
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"MINe 109" wrote in message
In article , "Arny Krueger" wrote: "MINe 109" wrote in message In article , "Arny Krueger" wrote: "MINe 109" wrote in message In article , "Arny Krueger" wrote: There's no doubt that el-cheapo direct turntables that have problems with speed control have made their way onto the market. However, the basic direct drive technology has far greater potential to provide excellent, long-lasting high performance than a belt drive. That these myths about turntable drive systems have persisted so long and remain so wide spread is a testimonial to the failure of high end manufacturers and publications to properly educate their public. Do you think audiophiles should abandon their highly functional belt-drives If you don't think its broken, don't try to fix it. because someone might someday market a direct-drive that fulfills this potential? Please explain why you think that this is so? Some myth-busting: direct-drive has greater potential, but there aren't any products. There aren't any direct-drive products????? That "provide [more] excellent, long-lasting high performance than a belt drive"? The right ones do. Existing good direct-drives are roughly equivalent to good belt-drives. Except for their obvious failings. |
#34
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
In article ,
"Arny Krueger" wrote: That "provide [more] excellent, long-lasting high performance than a belt drive"? The right ones do. There's the Rockport. What else do you have in mind? Existing good direct-drives are roughly equivalent to good belt-drives. Except for their obvious failings. Which are as theoretical as the "advantages" of direct-drive. Stephen |
#35
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"MINe 109" wrote in message
In article , "Arny Krueger" wrote: That "provide [more] excellent, long-lasting high performance than a belt drive"? The right ones do. There's the Rockport. What else do you have in mind? How about that Rockport? Would it have superior performance with idler or belt drive? Existing good direct-drives are roughly equivalent to good belt-drives. Except for their obvious failings. Which are as theoretical as the "advantages" of direct-drive. The advantages of direct drive are mainfest, not purely theoretical. Follow the logic - people who buy turntable are retro-technology fanciers, traditionalists. Belt drive is more traditional than direct drive. Therefore, other than turntablist turntables, whose sales numerically dominate the LP player marketplace, most turntables are highly traditionalist, retro technology designs. IOW, belt drive. It's all about perception amongst people who don't want things to change from how they were in the 60s and 70s. |
#36
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
On Tue, 6 Dec 2005 11:51:12 -0500, "Arny Krueger"
wrote: Existing good direct-drives are roughly equivalent to good belt-drives. Except for their obvious failings. Which are as theoretical as the "advantages" of direct-drive. The advantages of direct drive are mainfest, not purely theoretical. Follow the logic - people who buy turntable are retro-technology fanciers, traditionalists. Belt drive is more traditional than direct drive. Therefore, other than turntablist turntables, whose sales numerically dominate the LP player marketplace, most turntables are highly traditionalist, retro technology designs. IOW, belt drive. It's all about perception amongst people who don't want things to change from how they were in the 60s and 70s. Follow THIS logic - you buy a 15 year-old belt drive turntable instead of a new direct drive turntable that can be had for about the same price. Therefore, you have now shown yourself to be a Luddite who doesn't want things to change from how they were in the 60s and 70s. IOW, you've just a base reftro-technology fancier. Good for you, Arnold. You are making progess. |
#37
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
"paul packer" wrote in message ... On Mon, 05 Dec 2005 18:54:25 GMT, wrote: Do you think audiophiles should abandon their highly functional belt-drives because someone might someday market a direct-drive that fulfills this potential? I think that you should keep whatever functioning table you have until it no longer reasonable to do so. When it comes time for a new table get a proper Direct Drive. Or, heaven forbid, a CD player. Only if you care about hearing the most accurate playback possible. |
#38
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
Arny Krueger wrote: The mythology that direct drive turntables are inherently prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. The only thing I think about with direct drives, is all the ones I ever used had poor mechanical isolation. Some were so poor, that I could hear myself walk across the room. I went through at least two direct drives myself in the late 70's. The first one had this wonderfull add, about how good the construction was, and the use of concrete (it was really plastic with some kind of ingrdient). This was was absolutly horrible, a BSR. My second direct drive was a Sony, a little better. My introduction to cheap DJ setups in the 80's showed the usage of some cheap Technics turntables. The belt drives had good isolation, but the direct drive still had worse isolation than the belt counterpart. Perhaps the direct drives had a bad rap due to cheapness of some units. I think the record should be placed on a stationary platter inside a vacuum, and a Laser can scan the record. There would be no bearing noise, induced feedback , or resonance. greg |
#39
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
wrote in message
oups.com Arny Krueger wrote: The mythology that direct drive turntables are inherently prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. The only thing I think about with direct drives, is all the ones I ever used had poor mechanical isolation. Highly isolated turntables incorporating direct drive have been made. This appears to be a good example of a highly isolated DD turntable: http://stereophile.com/turntables/258/ A lot of current DD models are DJ turntables, which tend to be stiffly-sprung so that the LPs can be manipulated. |
#40
Posted to rec.audio.opinion
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More Direct Drive Turntable Myths
In article , "Arny Krueger" wrote:
wrote in message roups.com Arny Krueger wrote: The mythology that direct drive turntables are inherently prone to problems with "cogging" is much more about perception than fact. It is largely based on the myth that a rubber belt does a superior job of reducing speed variations. The only thing I think about with direct drives, is all the ones I ever used had poor mechanical isolation. Highly isolated turntables incorporating direct drive have been made. This appears to be a good example of a highly isolated DD turntable: http://stereophile.com/turntables/258/ A lot of current DD models are DJ turntables, which tend to be stiffly-sprung so that the LPs can be manipulated. Some of the DJ stuff I saw in the 80's, the floors would jump, and the turntables had to be special. I double isolated them. When I first used a CD player, I had to physically hold the player, so it would not skip! greg |
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