Re: Different t/t drive types - which is 'best'?
Posted: Sat Jun 27, 2020 11:11 pm
Not all belt drives are created equal, neither are idlers or dd decks for that matter.
There are fantastic examples of each. As an example, a Yamaha pf800 is about the only belt drive deck I would buy tomorrow. It has DC motor and a very heavy platter about a third heavier than an lp12 platter and bearing. And it has high torque. It also has its own odd arm. But its sound is completely different to most belt drives, almost direct drive like.
I have a thing for direct drives, I have 3 here at the moment. The one off dual I have built is something special, the dual Eds 1000 motor is unique. It also has a heavy platter. And a heavy inner platter. It's platter and inner platter are somewhere around the weight of an lp12 platter and inner platter, maybe a little heavier. It has overlapping drive coils, that create overlapping magnetic fields which make it incredibly smooth running because the magnetic field strength is maintained at close to constant as as each coil fires, the preceeding one is falling off at almost the same rate as the other is rising. Other configurations exhibit a 'gap' in the field strength as one coil switches off and the next one switches on. It doesn't sound like my other dd decks. Instead of having tight servo control it has fairly light servo control, flywheel effect and higher than normal torque.
My jbe has a fairly heavy platter, not a great deal of torque and fairly stiff servo control.
The jvc has a relatively light platter and heavy servo control as it is quartz locked. The heavy servo control subs in for torque to keep it stable which works fine.
For idlers I have the big lenco and a 301.
The lenco has high torque and heavy platter, the 301 has slightly less torque and lighter platter.
The idler on the 301 is horizontal, the one on the lenco is vertical.
The vertical idler gives a better top end but not so wide Soundstage due to the way motor vibration is transferred at 90 degrees to the record so affects the vertical motion of a stylus more than the lateral. the 301 has a wider Soundstage but rougher top end as it transfers vibration laterally, affecting lateral stylus motion more than vertical
Me, I marginally prefer the lenco to the 301.
The common theme for me is torque. Torque gives the deck control. I think it also means pitch stability is better because it isn't affected in an abrupt manner by external forces such as stylus drag, belt stretching on the side that is pulling and contracting on the side that is pushing, or traction loss of the idler due to contaminants on the drive surfaces.
Torque and flywheel effect smooth out momentary drive fluctuations, tight servo control stamps on it abruptly. Flywheel effect and torque go hand in hand for me, flywheel effect on its own coupled with a weedy motor means the control isn't there and the platter can run away, the motor can't control it
I much prefer smooth to abrupt
There is no best way to drive a platter round and round, there are several least worst sets of compromises.
Those compromises are what give rise to the characteristics of the decks
Just my thoughts on the question, might be a load of old bollocks
There are fantastic examples of each. As an example, a Yamaha pf800 is about the only belt drive deck I would buy tomorrow. It has DC motor and a very heavy platter about a third heavier than an lp12 platter and bearing. And it has high torque. It also has its own odd arm. But its sound is completely different to most belt drives, almost direct drive like.
I have a thing for direct drives, I have 3 here at the moment. The one off dual I have built is something special, the dual Eds 1000 motor is unique. It also has a heavy platter. And a heavy inner platter. It's platter and inner platter are somewhere around the weight of an lp12 platter and inner platter, maybe a little heavier. It has overlapping drive coils, that create overlapping magnetic fields which make it incredibly smooth running because the magnetic field strength is maintained at close to constant as as each coil fires, the preceeding one is falling off at almost the same rate as the other is rising. Other configurations exhibit a 'gap' in the field strength as one coil switches off and the next one switches on. It doesn't sound like my other dd decks. Instead of having tight servo control it has fairly light servo control, flywheel effect and higher than normal torque.
My jbe has a fairly heavy platter, not a great deal of torque and fairly stiff servo control.
The jvc has a relatively light platter and heavy servo control as it is quartz locked. The heavy servo control subs in for torque to keep it stable which works fine.
For idlers I have the big lenco and a 301.
The lenco has high torque and heavy platter, the 301 has slightly less torque and lighter platter.
The idler on the 301 is horizontal, the one on the lenco is vertical.
The vertical idler gives a better top end but not so wide Soundstage due to the way motor vibration is transferred at 90 degrees to the record so affects the vertical motion of a stylus more than the lateral. the 301 has a wider Soundstage but rougher top end as it transfers vibration laterally, affecting lateral stylus motion more than vertical
Me, I marginally prefer the lenco to the 301.
The common theme for me is torque. Torque gives the deck control. I think it also means pitch stability is better because it isn't affected in an abrupt manner by external forces such as stylus drag, belt stretching on the side that is pulling and contracting on the side that is pushing, or traction loss of the idler due to contaminants on the drive surfaces.
Torque and flywheel effect smooth out momentary drive fluctuations, tight servo control stamps on it abruptly. Flywheel effect and torque go hand in hand for me, flywheel effect on its own coupled with a weedy motor means the control isn't there and the platter can run away, the motor can't control it
I much prefer smooth to abrupt
There is no best way to drive a platter round and round, there are several least worst sets of compromises.
Those compromises are what give rise to the characteristics of the decks
Just my thoughts on the question, might be a load of old bollocks
