Editing Line level (section)

{{Short description|Standard audio signal level}}
{{For|the tool of the same name|spirit level}}

'''Line level''' is the specified [[Audio power|strength]] of an audio signal used to transmit [[analog (signal)|analog]] sound between audio components such as [[compact disc|CD]] and [[Digital Versatile Disc|DVD]] players, [[television set]]s, [[audio amplifier]]s, and [[mixing console]]s.

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 [[microphone]]s (Mic Level/Microphone Level) and [[Pick up (music technology)|instrument pickups]] (Instrument Level), and stronger signals, such as those used to drive [[headphones]] and [[loudspeaker]]s (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 card#General characteristics|sound card]]s) 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 line|unbalanced]], with a {{nowrap|3.5 mm}} (0.14&nbsp;inch, but commonly called "eighth inch") [[phone connector (audio)|3-conductor TRS minijack connector]] providing ground, left channel, and right channel, or stereo [[RCA connector|RCA jacks]]. Professional equipment commonly uses [[balanced line|balanced connections]] on {{nowrap|6.35 mm}} (1/4&nbsp;inch) TRS [[phone connector (audio)|phone jacks]] or [[XLR connector]]s. Professional equipment may also use unbalanced connections with (1/4&nbsp;inch) TS phone jacks.