Adjust LP12 speed the hard way:
One way to do it is by altering the tilt angle on the motor pulley. This is accomplished by loosening/tightening the two adjustment screws next to the pulley. These screws contact the casing of the motor and by loosening/tightening will tilt the motor (and pulley) for minor speed adjustments. A small amount of adjustment goes a long way, and you must first loosen one of the set screws before tightening the other in order to avoid deforming the motor casing. You need a strobe disk to check the result. The results are not ideal and ongoing belt and pulley wear make the speed fluctuate.
Adjust LP12 speed the easy way:
Fit a Zeus or Minos motor PSU to your Linn Sondeck. The Minos allows precise speed adjustment at both 33.33 rpm and 45 rpm by means of an easy software setting. Even better control can be achieved with the Zeus controller – this actually continually measures the platter rotation and keeps the speed rock solid. The Zeus can account for belt, pulley, motor and bearing wear.