thumpin wrote:I'm surprised that minute belt thickness speed variations can be heard by ear

Even when the Rega motor drive pulley slip on the shaft it hard to hear. BTW, have you checked your pulley RoDa?
Some recordings are bad enough to some like speed variation. I would focus my attention to this more than belts.
G'day
I'm also confused, surprised and annoyed that this can be heard.
But when the small variations from the original subplatter can be heard when it's replaced by a metal one, it seems more believeable that the same could be true for the belt..?
I have noticed that the pulley has a slight wobble, barely noticeable.
(I have seen it when the light fell on the top of the pulley once. Maybe I'll post a video of this if I can catch it on film)
If someone knows a how-to remove/refit the motor pulley, please let me know.
Would like to check if the motor pulley or the axle is the source of the wobble.
The white belt is tighter than the original, so it's possible that it affects the pulley? All is good when I'm using the original belt, though.
BR
R