PURPOSE: To surely detect a start ID by switching the cycle of a reference signal corresponding to the running speed of a magnetic tape by a reference signal generating circuit, and transferring a managing data stored in a demodulation circuit.

CONSTITUTION: The cycle of a reference signal SBSY is switched corresponding to the running speed of a magnetic tape 1. Therefore, when the magnetic tape 1 is reproduced at high speeds, a managing data stored in demodulation circuits 11, 12 is transferred to control circuits 4, 5 by a shorter cycle than when the magnetic tape is normally reproduced. Accordingly, the managing data is obtained a plurality of number of times in one cycle of the reference signal SBSY and positively transferred. Even if the magnetic tape is sent at higher speeds, a start IC can be detected surely.