Abstract: A capacitor is provided between an amplifier whose output impedance is relatively high and a cathode of a cathode ray tube. A transistor is also provided having an emitter-collector path connected in parallel with said capacitor and a base electrode which is connected to a D.C. voltage source through a switch which is turned on during a horizontal retrace period and off during a horizontal scan period. A D.C. restoring operation is achieved by causing almost all of the discharge current of the capacitor to flow through the emitter-collector path, resulting in less discharge current flow through the output impedance of the amplifier.