You'll need a step down transformer to convert the voltage from 240v to 120v.
They should sell the transformers at most reputable hardware shops.
When you get it, be careful how you connect the transformer, since doing it wrongly would send a voltage of 480v instead of 120v into your hardware.
In the case of tube amps, you'd be lucky to just blow a fuse and not the transformer, in the case of electronic hardware like preamps, you'd pretty much fry a fair amount of circuitry.
Hi, you can send it in to me to check if there is provisions within the power curcuit to mod it to our local voltage. Cost can be between $30 to $50. Just contact me at 97337161. My studio workshop is in Balestier.