definition of balanced and unbalanced

Discussion in 'General Electronics Chat' started by leon23, Aug 28, 2013.

  1. leon23

    Thread Starter Member

    Oct 11, 2008
    Can someone explain what these terms mean when it comes to inputs and guitar amps. Are they refering to impedances?
  2. cornishlad

    Active Member

    Jul 31, 2013
    Nothing to do with impedances. I'm sure you could google for a complete explanation but, in a nutshell, any source with just a ground and a "hot" pin is unbalanced. Typically a 1/4" jack (tip and ring) as used on any guitar I've ever seen.
    Balcanced sources , typically microphones from half decent and upwards have a balanced output. This requires ground and two signal carrying leads. A three pin XLR being a common example of a connector, although sometime a 1/4" stereo jack is used.
    The advantage of the balanced circuit/lead/input configuration is that it is far less likely to pick up interference (called common mode) if correctly terminated in the amp or mixer.
  3. Veracohr

    Distinguished Member

    Jan 3, 2011
    A balanced signal has the same signal on two wires, with the phase 180° apart. This is done to reduce noise picked up during transmission from the source to the destination. At the destination the two signals are put into a difference amplifier which eliminates (mostly) any noise picked up along the way, which will be common to both signals (not out of phase like the signal of interest) and thus attenuated according to the amplifier's common-mode rejection ratio (CMRR).
  4. #12


    Nov 30, 2010
    The balanced signals found in the music industry are usually low impedance, but "usually" is just a habit, not a rule.
  5. leon23

    Thread Starter Member

    Oct 11, 2008
    Thanks all, very helpful