Line level

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Line level is the specified strength of an audio signal used to transmit analog sound between audio components such as CD and DVD players, television sets, audio amplifiers, and mixing consoles. Generally, line-level signals sit in the middle of the hierarchy of signal levels in audio engineering. There are weaker signals, such as those from microphones (Mic Level/Microphone Level) and instrument pickups (Instrument Level), and stronger signals, such as those used to drive headphones and loudspeakers (Speaker Level). The strength of these various signals does not necessarily refer to the output voltage of the source device; it also depends on its output impedance and output power capability. Consumer electronic devices concerned with audio (for example, sound cards) often have a connector labeled line in and/or line out. Line out provides an audio signal output and line in receives a signal input. The line in/out connections on consumer-oriented audio equipment are typically unbalanced...

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