I have a Project low-end belt-drive turntable that I had no problem with in UK. It requires AC 16V, and a UK power adaptor with 230V/50Hz/Output AC 16V 500mA worked fine.
Last year, I moved to South Korea, where the AC wall power is 220V, 60Hz. When I used the UK power adapter with a plug converter, the turntable spun faster than 33rpm. I suspected the difference frequency, so I got a new power adaptor which takes 220V/60Hz and outputs AC 16V, 1.1A. But it still spins faster.
I don't think it is the belt (cannot imagine a belt failure that will make it spin faster)... Can anyone suggest a feasible point of failure in this case please?