Audio stereo<unk><unk>  made by Unitra The internal view of a Mission Cyrus 1 Hi Fi integrated audio<unk>  (1984) An<unk>  (or<unk>  amp) is an electronic<unk>  that<unk>  low-power electronic audio signals such as the signal from radio receiver or electric guitar pickup to a level that is high enough for driving loudspeakers or headphones.<unk> s are found in all manner of sound systems including sound reinforcement, public address and home audio systems and musical instrument<unk> s like guitar<unk> s. It is the final electronic stage in a typical audio playback chain before the signal is sent to the loudspeakers. The preceding stages in such a chain are low<unk>  audio<unk> s which perform tasks like pre-amplification of the signal (this is particularly associated with record turntable signals, microphone signals and electric instrument signals from pickups, such as the electric guitar and electric bass), equalization (e.g., adjusting the bass and treble), tone controls, mixing different input signals or adding electronic effects such as reverb. The inputs can also be any number of audio sources like record players, CD players, digital audio players and cassette players. Most<unk> s require these low-level inputs, which are line level. While the input signal to an<unk> , such as the signal from an electric guitar, may measure only a few hundred microwatts, its output may be a few watts for small consumer electronics devices, such as clock radios, tens or hundreds of watts for a home stereo system, several thousand watts for a nightclub's sound system or tens of thousands of watts for a large rock concert sound reinforcement system. While<unk><unk> s are available in standalone units, typically aimed at the hi-fi audiophile market (a niche market) of audio enthusiasts and sound reinforcement system professionals, most consumer electronics audio products, such as clock radios, boomboxes and televisions have relatively small<unk><unk> s that are integrated into the product.
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