Reality check: no belt, motor, AC, or anything else gonna make the lines "bounce back and forth" the changes in platter speed for that to happen are just insane, beyond the torque of the motor, and the OP wouldn't even need a strobe the table would be totally unlistenable.
Its just light hitting the strobe bars at the wrong time. Ignore those, concentrate on the average, you'll be fine.
Its just light hitting the strobe bars at the wrong time. Ignore those, concentrate on the average, you'll be fine.