Let's talk about the tape drive first: the tape and the magnetic head move at a relatively uniform speed, and the magnetic head will sense the remanence on the tape. The magnetic head coil converts magnetism into electricity, which is balanced and amplified by the amplifier circuit to push the electroacoustic conversion equipment (speaker or earphone) to make sound.

Let's talk about the disk drive first: the optical head emits laser, and the receiving tube turns the received laser into an electrical signal. After shaping, digital-to-analog conversion, and then amplification, it promotes the sound of speakers or headphones. Finally, the vocal mechanism is similar.