Wouldn't this affect the pitch? The only question is to what degree?
Any DJ will tell you that even touching the platter (not even the vinyl itself) during playback is audible, and they use MUCH higher torque turntables than hi-end audio setups.
it absolutely *will* affect pitch. even the stylus affects pitch. it's *only* the REALLY high torque motors that are minimally affected by *any* force applied to the platter.
when i set up my turntable, i adjusted the origin live's dc motor to proper speed with both a stylus in the record groove & the keith monks record sweeper on the record. remove either one, & the platter speeds up. it's all a compromise - you get different rate of drag when the stylus is at the beginning vs at the end of the record. so, you compromise & set the speed while the stylus is in the middle of the record...
doug s.