the slide plate 63 is mechanically or otherwise connected to a suitable sliding means for operation such as a power driven plunger or the like operation of the magnetic head system of this invention will hereinafter be described in full detail for the magnetic head 10 to play the forward track of the tape assuming that the angular position determined by the azimuth adjusting screw 40a is the position of the magnetic head for playing the forward track the slide plate 67 of the drive means 60 must be slided to the lefthand position by the sliding means not shown which will slide the slide plate to the righthand position for the reverse track of the tape following the sliding movement of the slide plate 67 the rack 61 is moved in the same direction as the slide plate through the leaf spring 66 rotating the rotary drum 20 with the sector gear 23 engaged with the drive means as shown in fig1 a to 11c simultaneously the arcuate projection 26 on the rotary drum 20 is also turned while keeping in contact with the engaging pin 57 of the locking means 50 mounted on the upper housing 31 where the rotary drum 20 is prevented from rotation by the rotating arm 24 on the rotary drum 20 through the corresponding azimuth adjusting screw the magnetic head in the rotary drum 20 is held in position for the forward track at this point where the rotating arm 24 on the rotary drum 20 abuts against the tip of the azimuth adjusting screw 40a the locking means 50 on the housing 30 has its engaging pin 52 engaged with the sloped end 25a of the arcuate projection 25 on the rotary drum 20 if azimuth.