It's recommended that you use the original Japanese AC adaptor that came with the Famicom, Disk System or accessories when playing in the United States or Canada. To do so will require a step-down converter.

The Sharp Twin Famicom AC adaptor has the following specs:

AC

AC100V

50/60Hz 21VA

DC7.6V 1.25A

- ------ C------- +
 

The Twin Famicom AC adaptor is equipped with the same prongs, and nearly the same input voltage (AC 100V) as AC adaptors used in the United States and Canada. The proper output voltage is DC 7.6V, 1.25A.

Never use an NES AC adaptor with your Twin Famicom. Most adaptors transform the electricity from AC to DC. The NES adaptor takes the input voltage down but still puts out AC, which is potentially harmful to your Twin Famicom.

To prevent from overheating and damaging your Twin Famicom, it's highly recommended that you use a step-down converter. Japanese electrical outlets output 100V, which is what the Twin Famicom AC adaptor is made to input. United States and Canadian electrical outlets output 120V. Step-down converters that will convert the electrical outlet output to 100V are available online and in stores.

www.voltageconverters.com