Depending on where you live a 3 pin cable on the Amp might not help. While investigating speaker hums I discovered the earth or ground pin in the 3 pin sockets in my condo studio/office/spare bedroom isnt connected to anything. There is ground on the distribution panel but the wiring is extended with two core cable. The new fridge has a 2 pin cable and an earth/ground screw on the back metal plate which has probably never been used on any fridge in Thailand. Its a wonder to me that more people dont get electrocuted when you have ceramic tiles, floods, 220volts. The modern trip switches seem pretty reliable though.
If you end up playing in clubs,pubs,bars or any kind of bigger commercial building get a radio mike. If you get between two phases of a 3 phase power supply that stuff will kill you.