An instrument amplifier is an electronic device which uses circuitry to converts the often barely audible or purely electronic signal of a musical instrument into an audible sound. An instrument amplifier is used with musical instruments such as an electric guitar, an electric bass, or an electric organ, to convert the signal from the pickup into an electronic signal that has enough power, due to being routed through a power amplifier capable of driving a loudspeaker that can be heard by the performers and audience. Combination ("combo") amplifiers include a preamplifier, a power amplifier, tone controls, and one or more speakers in a cabinet, a housing usually made of hardwood, plywood, particleboard, or, less commonly, moulded plastic. Instrument amplifiers for some instruments are also