Alternative platters ?

[MartinT]

Can I just check, the accountants , non-engineer take on this? Would I be right in concluding that the (very long) PFM thread establishes a methodology for testing the stability of the drive, establishes that it is valid after a few refinements, and produces plots where "perfect" would be a circle, and wobbles in the circle are bad?

It goes on to speculate about whether it can "see" the faults in the motor in question by counting how many wobbles there are, but this is inconclusive. What is clear is that fewer and smaller wobbles are good .

The only Technics 1200 tested is the one you supplied with MN bearing and Funk platter (presumably no record weight) and that measures remarkably well (its the plot you've been posting)?

That's agreed so far. I did use my Stillpoints record weight to produce that test reading.

And presumably the graphs show on paper what you hear on audition as the "warble"?

No, I didn't measure a heavy platter so I know of no graph that shows the speed regulation problem with a Technics and heavy platter. All we are doing is speculating that it may show the issue.

So, presumably, in the context of this thread, the next step would be to carry out the same test using the acrylic and strata platters, along with the technics original, MN ETP, and maybe MN copper, keep all other parameters constant (which means use a Mike New bearing to take the weight of the 10Kg platter) and see whether they have different shaped wobbles, and which one wobbles least? At the moment we don't know whether it is the inherent quality of the Technics motor which produces those plots regardless of the platter mass, or whether it is a "magic synergy" between the mass of the acrylic platter and the Technics motor?

Correct. I restate: we don't know what, if anything, we might see. However, some members have asked for objective measurement and I offered this as a way of seeing whether speed correction issues due to platter weight may be visible. It doesn't speak for platter material reflections or any other qualitative value of the platter.