AMX NXD/NXT-1200VG, NXD/NXT-1500VG, NXD/NXT-1700VG manual Wiring the NXA-AVB/RGB for Balanced Audio

Touch Panel Accessories

GND

IN-

IN+

GND

IN-

IN+

AUDIO IN

MIC OUT

GND

OUT-

OUT+

Left Channel	Unbalanced IN
	(Jumper IN- to GND)
Right Channel	Unbalanced IN
	(Jumper IN- to GND)

Microphone Unbalanced OUT

FIG. 5 Wiring the rear AUDIO IN and MIC OUT for use with Unbalanced Audio

Wiring the NXA-AVB/RGB for Balanced Audio

Professional audio equipment will often use balanced audio inputs and outputs, usually on 3-pin "XLR" connectors. A balanced audio signal consists of a pair of wires carrying the audio signal in anti-phase with each other (if one wire carries a positive voltage, the other carries an equal and opposite negative voltage).

The advantage of balanced audio over unbalanced audio is its ability to reject external interference added as the signal is carried over the wire. The receiving equipment takes the voltage difference between the two wires as the input signal. Interference will usually get added to both wires equally, and so gets cancelled by the receiving equipment.

The 3 wires used in a typical XLR lead are often referred to as Ground, Live (Hot) and Return (Cold). "Live" and "Return" carry the "in-phase" and "out-of-phase" versions of the audio respectively. The pins of the XLR plug/socket are as follows:

•X = Ground

•L = Live (Hot)

•R = Return (Cold)

When connecting the MIC OUT connector to a balanced audio input (FIG. 6), use all three audio terminals (+, -, and GND), then connect the "+" terminal to the "live" signal, the "-" terminal to the "return" signal, and the "GND" terminal to the ground signal.

GND

OUT-

OUT+

Ground signal
Return signal	Balanced OUT
Line signal

FIG. 6 Wiring the rear MIC OUT connector for use with Balanced Audio

VG-Series Modero Touch Panels 25