@icedquinn i can't give you a formula, but rpm ahould be the rough equivalent
@icedquinn because for higher frequencies you need higher rpm or tape speeds.
imagine the needle wobbling in the groove, you need a certain speed to be able to create a high frequency wobble.
@icedquinn i think https://en.m.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem is involved