To evenly advance the phases in a wide band, to eliminate the phase distortions and to make it feel that the sounds are heard in the front of an audio equipment, etc., by securing a serial connection between three and two stages of phase advance transformers to obtain a phase advance circuit that has a resistance connected to an open terminal.

A phase advance circuit of a phase advance transformer includes three stages (1) of phase advance transformer and two stages (2) of phase advance transformers which are connected in series to each other, and a resistance 8 connected to an open terminal. The states (1) and (3) are connected in series via a resistance 4 by the output of an operational amplifier 3, and an NF circuit comprises the resistances 8 and 5, a capacitor 6 and a resistance 7. Accordingly, the phases evenly advance in a wide band and the phase distortions are eliminated. Then it's possible to make it feel that the sounds are heard in the front of an audio equipment, etc.