Manual del usuario/
User´s manual
84
Aero-38
APPENDIX LINE CONNECTION: UN-BALANCED AND BALANCED.
.
There are two basic ways to transport an audio signal with microphone or line level:
Un-balanced line: Utilizing a two-conductor cable, it transports the signal as the voltage between them.
Electro-magnetic interference can get added to the signal as undesired noise. Connectors that carry un-balanced
signals have two pins, such as RCA (
) and ¼” (6.35 mm, often referred to as
) mono. 3-pin connector
such as XLR (
) may also carry un-balanced signals if one of the pins is unused.
Balanced line: Utilizing a three-conductor cable, one of them acts as a shield against electro-magnetic
noise and is the ground conductor. The other two have the same voltage with respect to the ground conductor but
with opposite signs. The noise that cannot be rejected by the shield affects both signal conductors in the same way.
At the device’s input the two signals get summed with opposite sign, so that noise is cancelled out while the
programme signal doubles in level. Most professional audio devices use balanced inputs and outputs. Connectors
that can carry balanced signal have three pins, such as XLR (
) and ¼” (6.35 mm) stereo.
The graphs that follow show the recommended connection with different types of connectors to balanced
processor or amplifier inputs. The connectors on the left-hand side come from a signal source, and the ones on the
right hand side go to the inputs of the processor or amplifier. Note that on the un-balanced connectors on the left-
hand side, two terminals are joined inside the connector. If hum occurs with balanced to balanced connections, try
disconnecting the sleeve (ground) on the input connector. Note that the illustrations show what should be
connected to what, but that pin locations on an actual XLR connector are different. Also, pin 2 hot is assumed on XLR
connectors.
Phono
jack
Cannon
Cannon
