Ezzel zárom, mert ez kifejezetten érdekes - és erősen digiális megoldás - a ROM-ban tárolt szinus referencia hullámmal:

"High-precision Motor Control for Ideal Rotation Conditions

The rotation control, which verifies and corrects the precision of the motor, uses the latest motor control technology cultivated in the development of Blu-ray disc devices, just as that used by the SL-1200G. Sine waves stored in ROM are used for the control waveforms at constant speed, and this achieves smoother and more stable rotation compared with using the simple sine wave generation with an external coil as in the conventional SL-1200MK5. In addition, the electrical circuitry has had tuning performed so that the newly developed motor of the SL-1200GR achieves maximum performance. The starting torque achieves 2.2 kg x cm with only a single rotor. The same startup time of 0.7 s (at 33 1/3 rpm) as the SL-1200G has been achieved."