Upgrade from TW Acustic Raven AC-3 to what?

Dear Dertonearm, I hate to harp on this issue, but I have a "thing" about bad science, such as your contention that the mass of the slate is a major determinant of the distance that a billiard ball will travel (and your bogus reason for saying so). I have done some reading on the physics of billiards, as a result of my consternation. Two things emerge from my research: (1) Once the ball is struck, the major contribution of the table to the distance and direction in which it travels is the static and rolling friction between the ball and the felt, as I surmised in the first place, and (2) slate is used for billiard tables not for its high mass per unit volume but because it can be worked to achieve a very flat surface, and once made flat, the surface of slate is very stable as regards humidity and temperature, i.e., it does not warp. Here I offer a reference to a pretty nice article I found on the internet that reviews the Newtonian mechanics of billiards:

http://archive.ncsa.illinois.edu/Classes/MATH198/townsend/math.html

Now if you can concede that your metaphor is ill chosen, perhaps we can also open our minds to re-examine the idea that platter mass is the sine qua non of the highest end turntables. If I could find an article that addressed your other bald statements, that a certain platter mass is needed, regardless of the drive system, and that the dynamic mass of the Saskia platter does not count as "mass", I would post those too. I don't have the requisite experience to disagree; I just don't think you have the "data", even of the subjective kind, to back up those two notions. The only defendable fact here is that YOUR turntable, which is a belt drive of a certain type and construction, sounded best with a platter of a certain minimum (high) mass when auditioned by you and your colleagues. (I don't know whether you made measurements of frequency response or speed stability that could be adduced to strengthen your case as regards your turntable, but if you did, I would be interested to see same. I am assuming your conclusions are based on subjective listening tests.) Now I can go bang my head against the wall, because my favorite football team just once again pulled defeat from the jaws of victory.

Sorry, here is complete URL:

http://archive.ncsa.illinois.edu/Classes/MATH198/townsend/math.html

Dear Lewm, dynamic mass of a TT is certainly important, as it adds considerably to its inertia (and is thus a matter too of the "geographical" dispersion of that dynamic mass in the horizontal distance to the "eye of the hurricane" - i.e. the bearing center), but in absolutely no way it adds to the mass "seen" by the record or stylus.
Why ?
You are standing on planet Earth - right?
Whether our planet spins or not doesn't alter its total mass.
Especially not the difference in mass between you and mother earth.
Now - if you jump from firm solid rock ground it will be different as if you'd jump from a suspended wooden floor and the landing will be different too - right?
Do I need to say more ?
I know that there are very few "physical facts" in audio life were audiophiles can agree upon, but can we agree on that?

Dear Lewm, again - ALL OTHER FACTORS are identical. Force vector of stroke, felt, air, humidity, everything except the thickness of the slate.
This elaborate analysis you found is what it is - a nice mathematical analysis of the forces, speed, impacts and angles occurring during billiard. It has nothing to do with the model we are talking about.
On the other hand I am certainly on no mission (as I do not believe in missions at all..) to convince you or anyone else.
If you do not agree to that model and to that principle of static platter mass and its contribution to undistorted tracking on the record you have a) a good large party on your side and it is b) totally fine with me.
As I mentioned before - just forget my silly ideas and model, don't bother anymore and continue as before.
Neither you nor anybody else have to accept nor buy that idea.
I certainly have no problem, but simply want to repeat one last time: ... ALL other factors (including the felt..) in that model are identical (just think about this for a moment - it tells the whole story - factor-elimination! - and it requires far less time than looking for written papers via Google......).
For your consideration - the increased thickness do bring one other factor into the "game" which too does contribute to the decreased tracking distortion as well as to the "longer run" of the ball on the table (and you won't find that covered in the maths either.....). But it makes little to no reason to discuss the next point when the first factor is still clouded.
Well, - I was used all my life to think and act far away the mainstream.
You do not find fresh grass (neither for your cows nor for your racing horses... ) if you walk on paths and grounds hundreds have walked before.

Dertonarm, Lewm, Dover,

I have been pondering the technical aspects behind TT speed stability in a qualitative way. I think there might be situations where mass plays an important role. I tend to think about this as AC vs DC, low vs high torque, low vs high platter Inertia (driven by mass). I tend to bracket in the following fashion:

1) Optimum

a) low torque, high platter inertia, AC
b) low torque, high platter inertia, DC

2) Moderately optimum
a) high torque, high platter inertia, AC
b) high torque, high platter inertia, DC

3) Not so optimum

c) high torque, low platter inertia, AC
d) high torque, low platter inertia, DC
e) low torque, low platter inertia, AC
f) low torque, low platter inertia, DC

What I’m basically trying to say is that a high mass platter may be able to “ride out” or sustain small speed instabilities introduced by either the motor or drag from the stylus/record interface.

I wonder if a high torque motor combined with a low enough platter mass begins to dominate speed instability in case there are speed instabilities in the motor. In other words, the platter inertia may not be high enough to dampen this effect if the motor torque is the dominant factor.

I would think that the low or high torque options with low mass option may be the worst.

I also wonder about AC vs DC motors. I heard that while AC motors are constant speed, DC motors are actually constant torque.

Any thoughts on these questions?