I recently bought these headphones from audiocubes and they arrived yesterday and worked fine with the US voltage transformer I have(I assumed US and Japanese was the same). Suddenly today I tried turning them on and I couldn't, so I found the other charger that came with them and that worked, but the one I had been using previously had stopped. I am now not using the headphones as I am terrified the other charger will stop working and then I won't be able to use these headphones. What should I do? Would using a japanese transformer (which I have now found are slightly different to the US ones) make it ok to use? Any suggestions would be most appreciated.