Michael says that the more (magnet) poles a motor has, the more cogging. And then:
I've never heard the "Technics sound" described the way he says. More of a muted/veiled sound which I attributed to undamped plinth and its tonearm. Is his analysis this "jitter effect" correct? I know that the Technics motor is 16 pole & 12 coils and I believe it is 3 phase certainly that would diminish greatly any cogging though I'm no expert.With nothing to counteract the motor cogging that inevitably occurs directly within the platter of a high-torque, low mass, direct-drive turntable, large amounts of wow and flutter are also inevitable.
Regulating a direct-drive motor's speed with a phase-locked loop produces tight speed control and measuralby low levels of wow and flutter , but the motor's constant, ultra-high-speed huntinging and pecking as it over and under compensates in the attempt to produce a consistent speed can create a jitter effect in the mid treble to which the human ear is particularly sensitive, adding a hard brittle texture to music. That describes the sound of Technics' now discontinued sl1200 series of direct-drive turntables, and explains why, despite their high build quality and relatively low price, few are used in serious audio systems, though some listeners claim that these tables can be modified to improve their sonic performance."