In a video tape recording and/or reproducing apparatus, a tape tension servo-system detects tape tension between a supply reel propelled by a voltage driven motor and the head drum to provide a corresponding detected tension signal supplied to a processor which is periodically interrupted for providing a control signal proportional to any deviation of the detected tape tension from a desired value and further for providing differential and integral control signals determined from the proportional control signal at successive interruptions and which are combined to form a control voltage signal for the supply reel motor. The processor is desirably constituted by a universal pulse processor and a central processing unit. The tape tension is detected by an angularly movable arm carrying a post about which the tape is wrapped sufficiently to ensure good compliance. The detecting arm and post are of light weight materials so as to be readily responsive to changes in tension and are arranged so that angular displacements of the area are not influenced by gravity.