Voltage difference for USB powered controllers

Controllers that are powered by USB only you will not require anything other than a spare USB port on your laptop/computer, but controllers that need a separate power adapter to work then you will need a power adapter that is made for your countries main power outlet (in your case 220-240 volts) so in your case any equipment you buy from USA that needs mains power to work you will need to buy power adapters or cables that take 220-240 volts……ALSO check equipments AMP rating aswell.
As far as i know the mixtrack pro is USB powered so no need for a mains power adapter.