Insure connection points are clean and free of corrosion. Model S1460 International AC Adapter (110/220V, 50/60Hz) and battery recharger can also be used. S1465 - NiCad battery pack is also available. TO INSTALL OR REPLACE BATTERIES Remove all plugs from amplifier. Slip a fingernail under battery door on back of amplifier. Remove battery pack from amplifier. Insert 10 new Alkaline “D” cell batteries, observing polarity, or NiCad battery pack. Carefully replace battery pack. Slide battery door