PURPOSE: To obtain an optimum head touch at all times, by detecting a read level of a magnetic cartridge tape, and moving a head forward and backward.

CONSTITUTION: An output of a read head of a W/R head is amplified by a read amplifier 3, and an envelope of the amplified output of the read head is detected by an envelope detecting circuit 4. A value of the envelope detected by the envelope detecting circuit 4 is compared with reference voltage 1' and reference voltage 2' by a comparator 5. When a result of comparison of the comparator 5 is sent to an input port, a microcomputer 6 calculates a driving direction and a driving quantity of a motor, which are required for obtaining a head touch by which the value of the envelope is inputted between the reference voltage 1' and the reference voltage 2'. Subsequently, in accordance with its result, a driving amplifier 7 is controlled from an output port. The motor 8 is driven by an output of the driving amplifier 7 to which a command is given from the output port of the microcomputer 6. The W/R head 2 is moved forward or backward by a rotation of the motor 8.