Definition: RCA connector

A plug and socket for coaxial cable. Introduced by the Radio Corporation of America (RCA) in the 1930s, RCA connectors are used for analog audio signals (see analog audio). They are also used for digital audio and analog video (see S/PDIF and composite video).

For decades, both the RCA and smaller 3.5mm mini-phone connector have been the most widely used plugs and sockets on consumer audio equipment (see mini-phone connector).

Also known as a "phono connector" because RCA designed it to wire an RCA Victor "phonograph" (turntable) to an amplifier. Only one cable was used as it carried a monophonic signal, not stereo. See A/V ports, phone connector and video/TV history.

RCA (Phono) Connector

The plug's centermost 1/8" by 5/16" prong connects the signal wire. The outer shell is ground, which connects to the sheath that wraps around the full length of the signal wire. See coaxial cable.

Ubiquitous RCA Sockets

Even in the digital age, consumer A/V equipment accepts analog audio (red/white) and composite video (yellow) via RCA jacks. See analog stereo and composite video.