Changing from 50 to 60 Hz or vice versa will impact the speed of a cd player, cassette deck, reel to reel and a TT.
That's only strictly true with synchronous motors. Others, such as DD, may not be affected. However, they may have other issues if not designed to run at the supplied frequency, such as overheating.
If you have a turntable with a synchronous motor, you can safely use a drive controller such as the VPI ADS to alter the frequency and, hence, motor speed. I think Walker also makes a unit and there are probably others.