anyway should have them, you can try yamaha at PS, or around pennisular to ask around. But normally i think they comes with a 2 pin plug, i remember last time my dad have to "ZHENG" it to 3 pins for me due to grouding issues.
Cheapest way is to just cut the plug top and replace it with our normal 13A plugtop. Normally that US plugtop is equipt with ground but the problem our socket just can't fit in the ground.
3 pin = grounded. All you really need is a travel adaptor.
If you want to be fussy about it, you can get a replacement 3 pin plug head from most NTUC outlets. If you want the whole cable, cheapest would be SLT - shops at the 3rd floor.
yeah.. but the only thing is that half the travel adaptors out there don't have a ground pin connected -- usually it's just a plastic thing so you can fit it in without needing another adaptor. make sure you get the right one