A magnetic tape recorder/reader including several magnetic heads (30-45) driven in a rotary movement at the periphery of an equatorial slot (4) of a cylindrical drum (1) on the surface of which runs a tape (7) wound helicoidally and a capacitive coupling device (20), the device being designed to transmit electrical signals between a part rotating around an axis connected to the heads and forming a rotor and a fixed part forming a stator, said device (20) including at least one coupling component (47-54, 73-80; 204; 220) comprising a mobile part (47a-54a, 73a-80a; 206; 222; 230, 232) and a fixed part (47b-54b, 73b-80b) connected respectively to the rotor and to the stator, characterized in that the mobile and fixed parts of the coupling component are made in the form of rings and/or segments of rings called coupling rings, respectively arranged in two mutually parallel planes (P.sub.1, P.sub.2) and perpendicular to the axis of rotation of the rotor, the mobile and fixed parts of each coupling component being arranged facing each other.