Turntable speed accuracy

Halcro Good work and thank you for your time spent on this.

I know that I am pitch sensitive and I believe it is most important perceptual feature in music.
Which is why I have never been satisfied with any of the belt drive turntables that I have owned so far.

But in general, a good direct-drive motor WiLL have more torque than a good belt-drive motor.

As a generalization that is incorrect. A DD drive has to spin at 33 1/3 rpm. In a belt drive, there is a tremendus amplification of torque of the motor afforded by the ratio between the motor diameter and that of the platter diameter. Add to that the possibility of a powerful motor, and you see what I mean. By no means is this an excuse to use a weenie little motor to drive a 20 pound platter though.

As an example the Atma-Sphere 208 is up to speed in 1/2 a revolution- not that far off from the SP-10, which gets there in 1/4 of a turn. Most of the delay on the 208 is the belt slipping on the motor, as it is up to speed before you can take your finger off of the 'On' button.

However the platter of the SP-10 is about triple that of the 208 in weight. The SP-10 in particular is an exceptional turntable, and thoroughly disproves that old idea that DD was somehow flawed. But it is the exception rather than the rule regarding DD, IOW the SP-10 motor has more torque than most any other motor in use in turntables. I am sure that is a large part of why it works so well. A robust drive is really important in a good turntable!

A robust drive is really important in a good turntable!

Very interesting comment. Jibes with the idea that the quality of the power supply is v. impt in amp and pre-amps as well. Not sure why, maybe its just a co-incidence? But after having my pre-amp's power supply upgraded, I am more convinced than ever that it is true for the electronics!

Halcro- Yes, I had read that and was trying to re-state it in a way that might make sense to those of us who are not musicians. Not sure how common this is amongst "us", but I cannot carry a tune in the proverbial bushel basket, let alone have any idea what a 12 hz variance in pitch means. I am in total awe of musicians, esp. singers!

A fast start up direct drive turntable does not necessarily have higher torque. Some DD tables boost the torque only at the first couple seconds to get the platter up to speed and then lower the torque to just enough to keep the platter running. The image that DD has higher torque is due to the popularity of Technics turntables, especially the SL-1200mk2 and SP-10mk2. But Technics is, of course, not the only name in the DD game.

_______