New turntable break-in?

VPI says 20 hours of breakin for their Superscoutmaster

I believe you. SME tables have this in manual. Bearing's need time to run in. And we're not even talking the electrical stuff with the internal tonearm wires that we all know help...

Yes I have experienced it and believe it to be a combination of table, arm, cartridge, interconnect and input into the phono preamp and hence to the preamp itself.

All breaking in at different rates to different degrees, depending on the complement of components.

And no two set ups will be alike in the rate and quality of break in, even if they share "identical" manufacturers and models.

Fascinating, fun and enjoyable.

I guess it doesn't get much mention because It's hard to tell how much is break-in and how much is tuning. On the one hand, the platter bearing, the belt, the tonearm bearings, and the cartridge suspension are all breaking in. At the same time, the cables are running in and charging up, or whatever suits your cable theory. And at the same time, there is user tuning, playing with all the things you mentioned and more--VTF, VTA, tracking alignment, azimuth, leveling, platforming, isolation, damping... So with so many simultaneously changing variables, the scientific method goes out the window and all you can do is wait, listen, tweak, rinse and repeat.

I'll tell you this: I share your experience on a more prosaic, inexpensive level. I got a Technics DD turntable at the beginning of March, and at this point I don't think anybody would have guessed it could sound the way it does now, which is to say rhythmic, dynamic, involving, organic. When I asked my wife, she admitted she never dreamed the turntable I pulled out of the box in March would sound the way it does now (in a good way).