In an equalizing filter circuit having an input terminal 101, an output
terminal 102, delay devices 104 connected in multi-stage to the input
terminal 101, and a plurality of weighting circuits 105 which are
branched from and connected to the plurality of delay devices to thereby
combine respective output signals of the weighting circuits, gain
adjustment of the weighting circuits is performed to determine a
coefficient of the equalizing filter circuit without depending on a load
connected to the output terminal. Thus, an amount of compensation for a
distorted waveform may be enhanced. To this end, an impedance converting
circuit 108 is connected between at least one weighting circuit and the
output terminal.