PURPOSE: To accurately retransfer a control signal by allowing the signal of a reproducing head to pass a variable attenuator and amplifying the signal and separating a low band component to convert it to a DC voltage and negatively feeding back a difference signal between this DC voltage and a reference voltage to the variable attenuator.

CONSTITUTION: The signal obtained by a reproducing head 5 only for control signal is allowed to pass a variable attenuator 6 and is inputted to an amplifier 7, and the low band component of the output is separated by an LPF 8. The output of the LPF 8 is converted to a DC voltage by a detector 9, and this voltage proportional to a tape speed is inputted to a comparing amplifier 10 together with the voltage of a reference voltage source 11. The difference signal obtained by the amplifier 10 is negatively fed back to the attenuator 6 to attenuate the input signal of the amplifier 7 to a saturation level or lower, and the amplified signal is given to a magnetic head driver 13 through a waveform shaper 12 and is retransferred to a tape 1 by a recording magnetic head 14. Thus, the control signal is retransferred accurately and stably against the variance of the tape speed and the variance of contacting between the head and the tape.