The specs for the AC Adapter are 120V 60HZ input and 9VDC 1Amp output. On the male end of the adapter which plugs into the machine, the external shield of the prong is ground (negative) and the internal receptacle is hot (positive). Plugging the wrong power supply into your machine WILL damage the electronics and will cost several hundred dollars to repair. The OD for the plug is 5.5mm.
These are available at a Radio Shack or similar.