Reply to Stanton Turntable running too fast

Heya.

A while back, I set out to buy a pair of used Turntables. I managed to lay my hands on a Technics SL-1200, and some Omnitronics Technics-knockoff. When I bought the Omnitronics TT, the guy who sold it threw in another belt-drive Stanton STR-50 TT (and 3 mixers) for no charge.

This Stanton TT has been standing around collecting dust for about a month now, but toevening I tried plugging it in to see if I could resell it. Lo and behold, it appears to be working. But when I put on a record I know fairly well, I notice that whilst the TT is playing the record and outputting sound without problems, the record seems to move a bit too fast. I check the strobes on the side of the platter, and it does indeed seem like the platter is sped up. I also tried decreasing the speed using the pitch fader, and managed to get to "normal speed" (record sounds right, strobes stay somewhat still) by moving the pitch fader to around -2.

So now I wonder, has anyone else had similar problems? I Googled a bit and saw a suggestion that I may be running it on 60hz power when it should be 50hz, but I really wouldn't know if that is the case. Any suggestions?