Stepdown transformer 240v - 220v



Hi Guys
I have a integrated amplifier that is set for 220v European and i need to use it on a 240v outlet here in Australia , the amplfier transformer is rated at 500va and the amp is 100wpc into 8ohm
what size stepdown transformer would i need ?
i have seen a stepdown that is rated at 600w - 2.7 amps
and a 1000w - 4.5amps .
I wish to maintain the best sound from the amp and don't want to restrict its power supply .
sorry but i am a bit of a nuff with electronics.

Thanks for your help

Phil.

Regards
Phil
steam3642
Hi Elberoth
Been away on travels
checked the mains and it is a constant 244v - 245v
i have noticed that A.m audio's current amplifiers still have 220v stamped on the back ,

Regards
Phil.
Does 220v with a squiggly line behind it and nothing else
imply it is 220v only ? as i have seen 220/240v on other equipment.
Received a response from the manufacturer and was informed

Nominal supply 220 VAC

Power transformer from 245 to 220 VAC minimum 1000VA.