That depends on how long you are going to stay in Singapore. If it is for long, then I suggest you sell the equipment and start from scratch since few years down the road, the 2nd hand market value for your old equipment will be low. If it is for short, then using a quality transformer is really an option. I don't recommend changing the internal circuitry as the equipment was not originally designed to do so otherwise there would be an external switch or the equipment can auto-adjust the voltage.
Good luck
Good luck