By Michael Miguest
I use both of these turntables in my system and both of these analog sources deliver beautiful music. The Thorens incorporates a belt drive system and the Technics incorporates a direct drive system. There are four other drive systems for turntables: the idler drive system, rim drive system, magnetic drive system, and loop drive system. My experience is limited to the belt drive and direct drive systems. However, this blog will attempt to give readers a little more than a cursory explanation of all of these different designs and their affect on your analog Front-End.
THORENS TD 126 MKIII
My Thorens TD 126 MKIII http://stereonomono.blogspot.com/2010/08/thorens-td-126-mk-iii.html is a Semi-
professional Transcription Turntable with a Servo controlled electronic belt-drive system with a DC motor. Aside from Load-correcting automatic pitch control (APC), ISOTRACK TP16 Mk III tonearm with very low effective mass, a Low resonance tonearm tube utilising "split wave technology", a Friction-free velocity-sensing electronic shut-off, a
Separate motor for tonearm lift operation,Three speeds 33, 45 and 78 rpm, and Precision craftsmanship, I chose this model Thorens because I believe AC motors in general are fairly noisy by nature of design compared to DC motors which are much quieter and smoother and exhibit no cogging. This combination yields an exceptionally, breath-taking, musically satisfying presentation. I use a Denon DL-103r cartridge on the stock ISOTRACK TP16 Mk III tonearm that feeds my Allnic AUT 2000 Step Up Transformer that feeds my restored Harman Kardon Citation 1 Pre-Amp's Phono input that feeds my VTL Deluxe Ultra-Linear tube Power Amp that feeds my Focal Utopia Diva Be
Speakers.
TECHNICS SL-1210 MKII
My Technics SL-1210 MKII with all of the KAB mods http://www.kabusa.com incorporates a Direct Drive system. In my humble opinion, this turntable's performance with the KAB mods competes with the best. Direct Drives have been wrongly vilified by many in the audiophile community. A direct drive with quartz-locked PLL gives you superior speed stability, low rumble, and higher torque, although not as high as a rim drive (negligible in most cases). Plus, there is no need to replace any rubber belts or idlers, ever. A good direct drive will sound very neutral, and will not add anything to color the sound. In addition, I use a Funk Achromat mat, a VPI center weight and a Denon DL-103 cartridge. The KAB external Power Supply mod is an efficient DC Power conditioner. Like an AC conditioner, a DC conditioner removes AC components "riding" upon the DC line. It removes 40dB of extranenous noise up to 100Khz. My Technics SL-1210 MKII is dead accurate and stable. However, its ability to correct for both static and dynamic load friction is uncanny. This, thanks to the frequency generator servo. Very few tables use this technology due in part to it's complexity and also patent infringement consideration. With this system, there are simply no speed variations which will negatively affect the Musical Presentation.
IDLER DRIVE SYSTEMS
Let's examine the Idler Drive system. Some examples of turntables that employ this drive system are the EMT 927/930, Thorens 124 (which is a hybrid), Dual 1229/1019, Garrard 301/401, Lenco L75 http://www.monoandstereo.com/2012/03/lenco-idler-wheel-drive-mk2-by-jean.html
If you consider that the energy that the cartridge receives from the record groove is purely due to the rotational energy in the record and, therefore, platter then the efficacy of idler drive becomes an obvious advantage. With no slipping or stretching belts between the motor and platter, the idler drive transfers motor torque to the record in the most efficient way possible from a suspended motor.
RIM DRIVE SYSTEMS
Examples of the Rim Drive systems would be TTweights Gem/Momentos Turntables, VPI, and Trans-Fi Salvation. Rim-drive is unique compared to any of the 3 major systems for driving the platter. It is also not quite the same as standard idler-drive, where the force of the motor is transferred to either the inside rim of the platter ( Garrard and Thorens) or to the underside of the platter ( Lenco) via a separately mounted and isolated idler wheel. (In the case of Thorens, it has a belt driving an idler wheel.) In rim-drive the energized driving wheel is directly connected to the motor shaft and directly in contact with the platter. Both Rim and Idler-drive tables have superior torque, and with a heavy enough platter they can be as noiseless as a belt drive, and very musical. The main reason to go this route is 'speed stability and torque'. However, the downside is higher rumble: because the platter is directly coupled to a high RPM motor via a rubber idler wheel. Rumble figures tend to be higher than a belt or direct drive, and is measurable, but is negligible to the ear on better models. High torque is desirable as a record with a heavily modulated groove (usually low frequency) can create enough stylus drag to slow the platter for the duration of the event, causing an audible artifact similar to 'wow' on a table with low torque.
MAGNETIC DRIVE SYSTEMS
Examples of this drive system would include the E.A.R. Disk Master Turntable
http://www.positive-feedback.com/Issue41/ear_diskmaster.htm, Brinkman Bardo, and Clearaudio Statement. This drive system incorporates a proprietary motor control that transfers just enough energy to the motor for it to remain at constant speed. The motor’s stator consists of four specially designed field coils, which are mounted concentrically with high precision around the platter bearing. Based on listening sessions we decided to forgo the typical 90-degree mounting angle in favor of a non-standard 22.5-degree roster, which, due to the magnetic fields overlapping, further reducecogging. The motor’s rotor also acts as the sub-platter and carries a magnetic ring with eight poles on its underside. Inside the motor, the rpm of a speedometer disc is measured and turned into variable voltage that is fed into a control circuit where the rpm is compared to the reference voltage that is adjustable via the trim pots. A separate heater for the bearing, as included with the LaGrange and Balance bearings, is not necessary. The motor circuit is kept under current all the time, just the speed is switched to zero or 33 resp. 45. In this way, the bearing is kept warm by the quiescent current of the motor drive.
LOOP DRIVE SYSTEM
An example of this system is 47 Laboratory's Koma turntable
http://www.ultrahighendreview.com/innovative-hi-fi-47-laboratorys-koma-turntable/ The 4724 Koma has twin contra- rotating platters. Sansui tried this concept back in the 1980's with their XR-Q7 and XP-99. The Koma's two solid aluminum platters spinning in opposite directions are driven synchronously by the same belt and float on neodymium magnets reducing friction and bearing noise.
CONCLUSION
EXECUTION IS EVERYTHING! All of these drive systems can be competent or incompetent, depending on
implementation. Enjoy The Music.
I use both of these turntables in my system and both of these analog sources deliver beautiful music. The Thorens incorporates a belt drive system and the Technics incorporates a direct drive system. There are four other drive systems for turntables: the idler drive system, rim drive system, magnetic drive system, and loop drive system. My experience is limited to the belt drive and direct drive systems. However, this blog will attempt to give readers a little more than a cursory explanation of all of these different designs and their affect on your analog Front-End.
THORENS TD 126 MKIII
My Thorens TD 126 MKIII http://stereonomono.blogspot.com/2010/08/thorens-td-126-mk-iii.html is a Semi-
professional Transcription Turntable with a Servo controlled electronic belt-drive system with a DC motor. Aside from Load-correcting automatic pitch control (APC), ISOTRACK TP16 Mk III tonearm with very low effective mass, a Low resonance tonearm tube utilising "split wave technology", a Friction-free velocity-sensing electronic shut-off, a
Separate motor for tonearm lift operation,Three speeds 33, 45 and 78 rpm, and Precision craftsmanship, I chose this model Thorens because I believe AC motors in general are fairly noisy by nature of design compared to DC motors which are much quieter and smoother and exhibit no cogging. This combination yields an exceptionally, breath-taking, musically satisfying presentation. I use a Denon DL-103r cartridge on the stock ISOTRACK TP16 Mk III tonearm that feeds my Allnic AUT 2000 Step Up Transformer that feeds my restored Harman Kardon Citation 1 Pre-Amp's Phono input that feeds my VTL Deluxe Ultra-Linear tube Power Amp that feeds my Focal Utopia Diva Be
Speakers.
TECHNICS SL-1210 MKII
My Technics SL-1210 MKII with all of the KAB mods http://www.kabusa.com incorporates a Direct Drive system. In my humble opinion, this turntable's performance with the KAB mods competes with the best. Direct Drives have been wrongly vilified by many in the audiophile community. A direct drive with quartz-locked PLL gives you superior speed stability, low rumble, and higher torque, although not as high as a rim drive (negligible in most cases). Plus, there is no need to replace any rubber belts or idlers, ever. A good direct drive will sound very neutral, and will not add anything to color the sound. In addition, I use a Funk Achromat mat, a VPI center weight and a Denon DL-103 cartridge. The KAB external Power Supply mod is an efficient DC Power conditioner. Like an AC conditioner, a DC conditioner removes AC components "riding" upon the DC line. It removes 40dB of extranenous noise up to 100Khz. My Technics SL-1210 MKII is dead accurate and stable. However, its ability to correct for both static and dynamic load friction is uncanny. This, thanks to the frequency generator servo. Very few tables use this technology due in part to it's complexity and also patent infringement consideration. With this system, there are simply no speed variations which will negatively affect the Musical Presentation.
IDLER DRIVE SYSTEMS
Let's examine the Idler Drive system. Some examples of turntables that employ this drive system are the EMT 927/930, Thorens 124 (which is a hybrid), Dual 1229/1019, Garrard 301/401, Lenco L75 http://www.monoandstereo.com/2012/03/lenco-idler-wheel-drive-mk2-by-jean.html
If you consider that the energy that the cartridge receives from the record groove is purely due to the rotational energy in the record and, therefore, platter then the efficacy of idler drive becomes an obvious advantage. With no slipping or stretching belts between the motor and platter, the idler drive transfers motor torque to the record in the most efficient way possible from a suspended motor.
RIM DRIVE SYSTEMS
Examples of the Rim Drive systems would be TTweights Gem/Momentos Turntables, VPI, and Trans-Fi Salvation. Rim-drive is unique compared to any of the 3 major systems for driving the platter. It is also not quite the same as standard idler-drive, where the force of the motor is transferred to either the inside rim of the platter ( Garrard and Thorens) or to the underside of the platter ( Lenco) via a separately mounted and isolated idler wheel. (In the case of Thorens, it has a belt driving an idler wheel.) In rim-drive the energized driving wheel is directly connected to the motor shaft and directly in contact with the platter. Both Rim and Idler-drive tables have superior torque, and with a heavy enough platter they can be as noiseless as a belt drive, and very musical. The main reason to go this route is 'speed stability and torque'. However, the downside is higher rumble: because the platter is directly coupled to a high RPM motor via a rubber idler wheel. Rumble figures tend to be higher than a belt or direct drive, and is measurable, but is negligible to the ear on better models. High torque is desirable as a record with a heavily modulated groove (usually low frequency) can create enough stylus drag to slow the platter for the duration of the event, causing an audible artifact similar to 'wow' on a table with low torque.
MAGNETIC DRIVE SYSTEMS
Examples of this drive system would include the E.A.R. Disk Master Turntable
http://www.positive-feedback.com/Issue41/ear_diskmaster.htm, Brinkman Bardo, and Clearaudio Statement. This drive system incorporates a proprietary motor control that transfers just enough energy to the motor for it to remain at constant speed. The motor’s stator consists of four specially designed field coils, which are mounted concentrically with high precision around the platter bearing. Based on listening sessions we decided to forgo the typical 90-degree mounting angle in favor of a non-standard 22.5-degree roster, which, due to the magnetic fields overlapping, further reducecogging. The motor’s rotor also acts as the sub-platter and carries a magnetic ring with eight poles on its underside. Inside the motor, the rpm of a speedometer disc is measured and turned into variable voltage that is fed into a control circuit where the rpm is compared to the reference voltage that is adjustable via the trim pots. A separate heater for the bearing, as included with the LaGrange and Balance bearings, is not necessary. The motor circuit is kept under current all the time, just the speed is switched to zero or 33 resp. 45. In this way, the bearing is kept warm by the quiescent current of the motor drive.
LOOP DRIVE SYSTEM
An example of this system is 47 Laboratory's Koma turntable
http://www.ultrahighendreview.com/innovative-hi-fi-47-laboratorys-koma-turntable/ The 4724 Koma has twin contra- rotating platters. Sansui tried this concept back in the 1980's with their XR-Q7 and XP-99. The Koma's two solid aluminum platters spinning in opposite directions are driven synchronously by the same belt and float on neodymium magnets reducing friction and bearing noise.
CONCLUSION
EXECUTION IS EVERYTHING! All of these drive systems can be competent or incompetent, depending on
implementation. Enjoy The Music.
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