If it's an electronic coffee maker, it may have a switch in the back somewhere for 50 or 60Hz operation, mainly because the internal clock (if any) may be synchronized off of the line frequency. If it is a pump espresso maker it may have a motor, which may be an issue with frequency although many of them use a little PMDC motor, which would not care. You really need the manual for the coffee maker.
Originally Posted by Besoeker
"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)