VPI acrylic vs. aluminum

"The Classic platter... in addition to being self-leveling, is also self-centering." Which means what exactly? And why would I care?

So far as I know, my platter is level and centered and has no play whatever that I can discern.  Is there play in the Classic bearing?

I can only speak to my experience with the platters that work with non-inverted bearings where the platter sits on top of the bearing supported be three set-screws where the spindle has rubber o-ring/s to off-set (some) of the play that is inherent in this design.

I use a square or something that I know is square (sometimes a business card works if checked for square, or you could invest in a dial indicator) to set on the plinth close to the platter as it spins. I've always seen the need to adjust the platter on the bearing by sliding it slightly in one direction in order to get close to no wobble or "out-of round" as possible. (With the Classic platter/bearing design, the only way for it to be off-center would be for a machining error, otherwise, there is no play there). (I find it hard to believe that anyone who's ever checked this, hasn't experienced the same thing.) This is why when I say the Classic platter is "self-centering" it makes a big difference. The only other possible measurement left to deal with is the precision of the machining of the run-out tolerances for the platter to run true, therefore have correct, consistent speed leading to more musical satisfaction. I believe, according to VPI, the Classic platter has closer machining tolerances that most older platter designs. (This is why I care.)

When one obtains more expensive, more closely machined devices... this is where a lot of the improvement in sound quality originates and separates good sounding components from great sounding components. (Another reason why I care.)

One more point: in anything mechanical, in the case of this forum post, (turntable, tonearms, cartidges,) machining tolerances are extremely important in overall end musical satisfaction. Take some cartridge lines for instance, the only difference in some models are the closer tolerances that were found after the manufacturing/machining process was completed for a specific model, and only, after final testing of these parts, found to be much better sounding, therefore the manufacturer creates a new model that sounds better/costs the end user more (costs the manufacturer no more) from the batch of original cartridge parts for one specific model.

melm: With all due respect, I've read through this discussion a few times. Even though I've tried to explain my personal experiences with these differing platters/bearings, you have, (without as much personal experience, as you stated), have again & again asked questions that show that lack of experience or thoughtfull reasoning that should be considered here. The questions you've continued to ask, show this. It seems you have either an unwillingness to accept others' personal experience without careful thought or the fact that ongoing improvements in mechanical design/machining tolerances, just may be an improvement to your listening experience. For these reasons, I will not post here again.

I only hope the OP has gained some insight here.

I hope you all have a good day.

What is a mag/level platter?