Direct drive/rim drive/idler drive vs. belt drive?

Hi,
having read further through this thread one thing comes to mind: The actual length and shear thickness, mostly width of the belt in use.

Some say that this is of quite some importance and actually kept the belt VERY short (pulley under the platter) and beefy, (not thin, round or square) like the flat belts e.g. SME and Linn use.
Then there is the motor controllers, ‘done over’ a number of times by Linn, and at least once by SME.

Listening to a thin (square) belt of a top Pro-ject table and thin (round) on TransRotor Z3 (sans controller) and then a short (flat) belt with controller on SME gives a pretty clear indication of the difference in transience/attack.
So much so, that on VERY dynamic vinyl the LP seems to 'slip' on the platter (rather then the belt) in the case of the SME -- if the LP is not fixed with the clamp provided.
This raises the question of 'slippage' of the vinyl on the platter in the case high torque direct OR belt drive, and if no platter clamp is used or even available.

Lastly, if the drive is THAT tightly coupled, then the motor controller's performance comes a LOT more to the fore. With the hole drive line becoming so much more unforgiving with next to no measurable 'slip' it is now unable 'paint over' some dynamic ‘problem passages'.
Fix one thing, and it will reveal the next issue for sure.

‘Too much’ platter weight (never mind just the main bearing implications) in such a 'tight coupled' scenario may just 'over-load' the motor/controller, running behind torque demand and its reverse, producing delay and over-shoot if the platter's inertia is out of tune with the motor's torque delivery and the controllers feedback loop speed.
All this can explain why a more 'benign' coupling might sound better or more natural, even if slightly less 'dynamic'.
Greetings,

The flaws in the way most vinyl was mastered will far out weight what 'perfection' that you chase in the TT design. Once you arrive at the 'perfection' design, it will be time to move on to a base that is no less than a $10K electron microscope table. Then on to other parts of the chain. Please, just enjoy the music.

We will always have different opinions about what platter drive is the "best" because we see here -again - different "schools".
I - again - just want to mention the fascinating idea first proposed by japanese audio engineers about using the string on heavy platter and working with a WANTED and precisely tuned "slip".
This works just great with a precise platter of considerable weight and inertia.
The string with minimal grip and minimal tension does indeed minimize any speed alternations, transmitted vibrations and just have to prevent the platter from loosing speed.
The (only...) trade-off is a long time till constant speed is obtained (1-2 minutes).
On the other hand we have the minimal possible influence from transmission, motor etc towards the platter.
Its the basic principle behind the big Micro Seiki, Melco and Epic turntables.
Add to this the concept of putting the bearing free from horizontal force (counter-bearing) and you have a smooth TT principle which just needs a considerable amount of space, weight, precision tooling (these 3 = money....) and care.
But - as in most other audio "fields" - different "schools" will favor different concepts and "models".

In my opinion theory doesn’t really matter because we can debate it forever and never come up with a consensus. All that really matters is what sounds best to the listener.

The "whatever sounds good" opinion is a consumer attitude and there's nothing wrong with that but can never work as and apply to science nor truth seeking. I certainly hope people who do manufacturing has done more research than just "whatever sounds good" and came up with more educated decisions. Therefore I completely support the kind of work Mr. Mark Kelly has done and appreciate the time he spent in experimenting and, even more importantly, sharing his findings in print with us. Thank you Mr. Kelly.

I have experience with all three drive systems and they all can sound good but, right now, I completely reject using a soft rubber belt. If a turntable has to use something that soft to filter vibration and masking speed irregularities then it needs a better motor, period. In the last decade in belt-drive manufacturing, much has been belabored on fancy platter, thick and shiny, and bearing, thick and shiny, but little has been focused on the actual motor. Enough with wimpy toy motors already!