Sound Pickup

a device that converts mechanical vibrations into electric oscillations in order to reproduce mechanically recorded sound. It has two basic parts, a head and a tone arm. The head is an electromechanical transducer, which converts the mechanical vibrations of a needle that is moving along the groove of a phonograph disk into an AC voltage. The tone arm, a rod with the head attached to one end, ensures the proper position of the needle in the groove. The heads are chiefly of the electromagnetic and piezoelectric types. The electric voltage developed in the head is usually small and requires further amplification. Sound pickups are manufactured for the reproduction of monophonic and stereophonic sound recordings on phonograph disks by record players and radio phonographs.