Hi Gary,
I don´t know Voyd turntables, just that the company was bought by Audio Note, so I guess that Peter Q knows it better than me ... BUT:
I have read in their webpage that AN tables have AC-synchronous motors.
These AC motors vary their speed with voltage frecuency.
In UK frecuency is 50 hz, in USA 60 hz.
So if your table has a UK motor, you CAN NOT use it in USA.
A SDT will only change voltage, but not frecuency.
If you want to change frecuency you´d need a frecuency converter, which are (I think) much more expensive than a motor, and I don´t know if they work so fine as to be used in a turntable.
I think that the voyd has 3 motors and, if it´s not in production today, it would be a problem to get them, so you´d have to get another brand.
Sure there are more expert people than me.