Abstract: In accordance with a method of recording and/or reproducing stereophonic information in two adjacent tracks of a magnetic record carrier, an auxiliary signal whose frequency content is situated outside the frequency spectrum of the stereophonic information is recorded in the tracks and in the magnetic record-carrier area between the tracks during recording. During reproduction, the auxiliary signals read from the record carrier by the two transducers is used to control the gain of a pair of variable amplifiers so as to ensure that the amplitudes of the stereophonic information signals thus reproduced are independent of tracking errors.

Abstract: A magnetic converter having a magnetoresistive element, the resistance of which is measured by means of an alternating current having a frequency which is larger than 8.rho./.mu.D, where .rho. is the resistivity, .mu. the magnetic permeability and D the cross-section of the element so that the current distribution is concentrated at the edges of the element due to the resultant lateral skin effect.

Abstract: In a magnetic tape drive arrangement having a tension-controlled loop, with the tension in the part of the magnetic tape upstream from the loop being maintained constant as far as possible by suitable means in a conventional manner, compensation of variations of the tension of the magnetic tape in the loop as the result of variations in the coefficients of friction of the magnetic heads due to changes in temperature and humidity, is provided by an element which frictionally engages the magnetic tape upstream from the closed loop, coefficient of friction and angle of contact of the element being selected in accordance with a specific relationship.

Abstract: A servo system for controlling the position of a magnetic reading head relative to the center of a selected information track. During recording a long-wave positioning signal is recorded below the data signal in the tracks. Upon reading out, the head not only reads the information of the selected track but, as result of cross-talk, also the positioning signals of the adjacent tracks. After filtering out and processing the positioning signals, a control signal for controlling the head is obtained.