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Cinch [ ˈsɪn (t) ʃ ] (in German - deviating from the pronunciation of the English word of origin - often pronounced [ ˈtʃɪntʃ ]) is a de facto standard for coaxial connectors . It is used for signal transmission , for power supply or for connecting speakers . It can be used to transmit direct or alternating currents , low frequency signals ( audio ), high frequency signals ( video ) or antenna signals (TV). The electrical load capacity is usually designed for 30 VAC / 0.5 A, with high-load variants up to 250 VAC / 10 A with a dielectric strength of 1 kV being offered.

The American names are RCA connector (or RCA for short ), phono connector (from phonograph "record player") and Cinch connector .

Cinch plug (audio).
White (or black) for the left
stereo channel , red for the right stereo channel
Connector for composite video connections (yellow) with additional audio connectors (red and white)
The three plugs of a component video connection
Gold-plated cinch socket

Concept and history

The connector for coaxial cables was developed in the early 1940s by the Radio Corporation of America and replaced the loose 1/4 "= 6.3 mm jack plug in the USA . The English noun cinch means, among other things," firm grip ", the verb to cinch means, among other things, “ to lash .” In the USA, the terms phono jack or phono plug are also common.

This audio turntable standard was imported into Europe; before that, domestic manufacturers also used the same symmetrical standard for the turntable input as for the 2 × 4 mm mains plugs (not Schuko , compatible with the individual 4 mm tuft plugs or banana plugs ) . DIN connectors were later used in Europe , while Tuchel connectors were already available in the professional sector .

In addition to analog audio connections, the cinch connector is also used for digital signal transmission with the S / PDIF interface.

Levels and impedances

The typical Line - NF level for jack is approximately -6 to +6 dBV (0.5 to 2 V eff ). The 1 volt standard is common in America, the DIN level is 0.775 volts.

The impedance or AC resistance of a signal output is between 200 ohms and 2 kΩ, with signal inputs from 10 kΩ to 1 MΩ. The CCITT standard = 600 Ohm applies to applications in telecommunication technology (telephone), measurement and studio technology.

Color coding

Analog audio

The red or yellow connectors correspond to the right channel, the black or white to the left.

  • White or black: left channel, if both are available: white for playback, black for recording.
  • Red or yellow: right channel, if both are available: red for playback, yellow for recording.


  • Composite video
  • Component Video:
    • Green: Yy ( component video , brightness)
    • Blue: Pb (component video, color difference)
    • Red: Pr (component video, color difference)


There are adapters for many different combinations. The following are common:


Cinch plugs are two-pin and each transmission channel requires its own two-pin cable. What can be transmitted via a five-pin DIN plug requires four individual cinch cables. The swapping is prone to errors.

They are unsuitable for professional, low-interference, symmetrical signal transmission that is at least three-pole.

Two parallel coax outer conductors of different lengths can form a ground loop and cause interference.

The contact is not safe due to dimensional deviations and loosening leads to faulty loose contacts or hum.

Cinch plugs should only be inserted when the device is switched off, as the inner contact is "leading" . When plugging in under load and with the amplifier turned up, high voltage peaks can destroy components and very loud crackling or humming sounds can cause hearing damage.


For cinch connections, twisted or untwisted two-core cables (power supply, loudspeakers) or shielded coaxial cables are used , depending on the purpose . As with twisted pairs , interference fields have no influence here.

More audio and video connectors


  • Michael Ebner: Manual of PA technology , 1st edition. Elektor-Verlag, Aachen 2002, ISBN 3-89576-114-1
  • Siegfried Wirsum: Practical sound reinforcement technology. Device concepts, installation, optimization . Franzis-Verlag GmbH, Munich 1991, ISBN 3-7723-5862-4
  • Rolf Beckmann: Manual of PA technology. Basic component practice , 2nd edition. Elektor-Verlag, Aachen 1990, ISBN 3-921608-66-X

Web links

Commons : Cinch plug ( RCA in English)  - album with pictures, videos and audio files

Individual evidence

  1. Oxford Dictionaries: cinch , accessed on November 4, 2014.
  2. Datasheet (PDF; 29 kB) Kobiconn RCA Jack Panel Mount