An equalizing circuit is provided for a playback apparatus not requiring tracking control. A playback signal is supplied to a plurality of unit delay devices which are connected in series, and the signals at the input ends and the output ends are supplied to weighting devices, respectively. Furthermore, the playback signal is supplied to a computation circuit, whereby weighting coefficients are determined. Weighting is performed on the signals from unit delay devices, and these signals are added together by an adder so that the equalization of the playback signal is performed, and the signal is extracted from an output terminal. Simultaneously, in the computation circuit, when the envelope value of the playback signal is within a range the phase lock for the playback signal is used so that the calculation of the weighting coefficients is done, and the coefficients of the weighting devices are changed.