Grand Cinenova 5 channel...This amp has a 4kva trans inside which the dealer says, tends to trip breakers due to high current draw during start up..thus the 32 amp
4000 va divide by 230V = 17.39 amps. That amp should have its own dedicated circuit. That is if the amp will be on at the same time as the other amps. And with that said I doubt a 20 amp breaker would withstand the initial inrush current if the primary of the transformer does not have a soft start circuit.
Code in Singapore, I have no idea. In the US the largest breaker that could be installed on a branch circuit feeding a NEMA 5-15R duplex receptacle or a 5-20R receptacle is 20 amps.
What is the current rating for your receptacle, is it rated for 32 amps?
You really need to direct your questions to the electrician that did the electrical work for you.