PURPOSE: To attain automatic wave form equalization efficiently, by incorporating a DC feedback circuit and a limiter circuit to an error amplifier amplifying an error signal of a TV video signal.

CONSTITUTION: The TV video signal is led to a transversal filter 3, a part of about 1/2 horizontal period before and after a forward edge of a vertical synchronizing signal is taken as a reference signal and an error signal of an input signal to the reference signal is amplified 13. The limiter characteristic is given to the input/output characteristics of the amplifier 13 to limit the output of the amplifier 13, and the delay section 15 is operated in the dynamic range to keep stable operating state. A DC feedback circuit is provided to the amplifier 13 to avoid the effect of offset.