Turntable speed accuracy

Hi Chris,
My statement was directed at the 'speed' of any correction performed by the motor controller being felt by the platter?
I don't think there is any doubt that in a DD situation with the platter being attached to the motor......any speed correction will be effected faster than via a belt or thread connected to a motor/s at some distance from the platter?
If you re-read Peter Moncrief's excellent article that I posted several times........he provides a great deal of information regarding this very subject.

I'm not sure what the differences might be in a turntable designed for a string/thread drive over a belt?
Can you or someone provide some further thoughts on this subject?
Regards
Henry

Halcro, you have done a fantastic job bringing us up to speed on this and also leading the way on trying alternative ideas on your Raven. However I must pull you up on a couple of comments on DD
"The differences between the two drive types I believe, has to do more with the speed of any correction applied once a deviation is detected?
In this.....a belt or thread drive is at a severe disadvantage.
The DD motor....usually with a lot more torque than that of a belt/thread drive....and being directly connected to the platter.....can correct deviations in micro-seconds theoretically inaudible to the human ear."
Thread drives do not self correct as DD's do.
Didn't your mother tell you 2 wrongs don't make a right ? You could argue a DD is twice as bad as a thread drive. One assumes if there is a time slippage and it is a one off why stuff the next few seconds of music trying to catch up ?
Then there is the correction of the correction when the DD overshoots on correction.... as my learned engineer tells me, nothing wrong with DD's they are only a little bit out all of the time.
"The DD motor....usually with a lot more torque than that of a belt/thread drive"
This is a presumption, I'm not sure it is correct. I'm not sure how many DD's could spin my 20kg plus platter up to speed in less than one revolution as does the AC motor on my thread drive.
But to balance the argument I still lust after an SP10mkIII for a second deck.

I said it once before long ago- any tt motor that brings the platter up to speed in about a half of a revolution (less than one revolution) has plenty of torque to hold speed stable.
Also, I wanted to be the 300th poster on this thread. Yay!!

I vote a moratorium on these endless circular arguments over the merits and demerits of this or that drive mechanism. Lets just see how various ones of them work according to Timeline. But in general, a good direct-drive motor WiLL have more torque than a good belt-drive motor. However I will not claim that this per se makes one better or worse than the other.

I am also wracking my brain to think whether I know anyone who can test the Timeline out of context (meaning not by using a turntable). Some sort of light-sensitive timer is needed.

This is an interesting discussion with philosophical, theoretical and practical elements. I am not in any way an advanced thinker or practitioner on things analog. However, I don't think anyone has addressed these issues with respect to a mylar tape drive, which is essentially inelastic. I will say that I believe that unless you have perfect pitch, I would think that it would be better to have a TT whose speed has better precision than accuracy. IOW, within certain bounds, speed stability is more important than speed accuracy. A table that runs at 33.6 rpm, +/- 0.05 rpm, would be preferable to a table that runs at 33.3 rpm, +/- 0.5 rpm. I made those #s up to illustrate my point; I have no idea how audible those variations would be but I hope you get my point.