Difficult to answer when equipment make & model are not specified. Presumably when connected to the rest of your system, power will be delivered by another unit box else you would not ask this question - you do not mention your country USA = 115V 60Hz most of the rest of the world = 230V 50Hz - Your motor is very likely to be powered by AC current to give precise speed control - A DC motor will usually vary in speed depending on supplied voltage - my GUESS then is that the turntable uses your local mains power. But I could be wrong...
Peccavi
December 2009