Using a U.K. spec (230 VAC/50 Hz) Esoteric X-01 in the U.S.A.

The plate on the back of my U.K. Esoteric X-01 states 220-240 VAC/50 Hz.  The units sold in other markets appear to operate on both 50 or 60 Hz.  I've contacted Esoteric U.S.A. and they no longer supply the U.S. spec. transformers.  How might I safely use my X-01 stateside.  Can I ignore the cycle difference and simply use a step up transformer?  All advice much appreciated.