Balanced circuit

A balanced circuit is a way to connect electronic systems together so that they can exchange electrical signals (like sound) while avoiding interference.

To do this, one uses a cable with two or more wires. The cable is balanced if the impedances of the two wires are the same. This causes the noise to be common-mode (the same on both wires). Since it is easy to remove common-mode noise, a balanced circuit is a good way to keep noise out of electronic systems.[1]

When used to send sound, balanced cables use XLR connectors or phone connectors. Balanced circuits first became common in early 20th century telephone lines.

References

  1. G. Ballou, Handbook for Sound Engineers, Fifth Edition, Taylor & Francis, 2015, p. 1267–1268.