A pickup device is a transducer (a Variable reluctance sensor to be specific) that captures or senses mechanical vibrations from stringed instruments such as the electric guitar, electric bass guitar, Chapman Stick, or electric violin, and converts them to an electrical signal that is amplified using an instrument amplifier, such as a guitar amplifier or a bass amplifier to produce musical sounds through a loudspeaker in a speaker enclosure. The signal from a pickup can also be recorded directly, using a DI box (a common practice with the electric bass) or broadcast on the radio or television. Most electric guitars and electric basses use magnetic pickups. Acoustic guitars, upright basses and fiddles often use a piezoelectric pickup.