I need repair help

I have a Stax 007t head phone amp US version ie 117v.I need to repair the unit any recommendation other than sending it to Japan.
Contact Accutech Service Center, 16617 S. Normandie, St C, Gardena, CA 90247. Phone 310-324-7406. They're the importers trading under Yama's and servicing under Accutech.