As Bill suggests voltage regulator is a great suggestion and will insulate you against line variation.
Another choice would be a "variac", a variable transformer. This takes in 120V from the wall plug and allows you to choose whatever voltage you want with a knob. A variac rated for 75W shouldn't be too expensive, and is probably available from Digikey or Mouser, both of which are highly reliable electronics distributors. I use a variac for the heating mat under my developing trays, it allows me to maintain chems at 70F in the winter in my otherwise-underheated darkroom.