PURPOSE: To suppress a variation of a reproducing transmission characteristic caused by a variance of a head coil parameter, by constituting a negative feedback amplifying system, of a reproducing amplifier and a rotary transformer for output of a head.

CONSTITUTION: A reproducing signal which has been detected by head 1 passes through a rotary transformer 2, it is inputted to a reproducing amplifier 4 through a shielding wire 3 from a drum stator side winding terminal 2c, and its amplifying signal is sent to a signal processing circuit. Also, simultaneously, an output of the amplifier 4 is inputted to a feedback circuit 5, and its output supplied to a drum stator side winding terminal 2d of the transformer 2. As a result, the reproducing transmission characteristic comes not to depend on a capacitor and a resistance, and the transmission characteristic can be controlled by a transfer function of the feedback circuit 5.