10/28/2017 XKITZ XAMP-D2
Input Signals – Balanced or Unbalanced
There are two basic systems used to connect the audio signal on consumer and pro audio equipment;
unbalanced lines and balanced lines. Unbalanced lines use one wire for signal and the other for ground.
Balanced lines, on the other hand, have two signal wires and a shield ground wire.
Unbalanced lines are most common in consumer grade audio, and are generally much more susceptible to audio
noise li e 50/60Hz hum. Unbalanced lines will also pic up any electro-magnetic noise in the nearby
environment (such as computers, cell phones, microwaves, etc.) and adds it to your audio signal, ma ing it
audible in your spea ers. Unbalanced lines can also lead to ground loops, which are the major source of
50/60Hz hum in your sound system. Ground loops arise whenever there is more than one path from any piece of
audio equipment to earth ground. Your equipment will always be grounded through your AC line. Adding
another path to ground through your unbalanced audio cable adds a second path to ground, and this can cause
audible 50/60Hz hum.
Balanced signals are more common in high end consumer and professional audio systems and are much less
susceptible to noise. Balanced lines allow you to run very long audio cables without allowing electro-magnetic
noise to couple into your signal. They’re also not susceptible to 50/60Hz hum; there is no connection to ground
in the audio signal cable, so they can’t create ground loops in your sound system.
For unbalanced signal input, connect your signals to the RCA jac s.
The figure below shows the wiring of 2x5 connector J5, which has the balanced (+) and (-) inputs, and controls
and status flags.
Figure 2. J5 Connector - Balanced signal Inputs, and controls
Pin Si g nal D esc r ip t i o n
1 RESET_N Connect to GND to M ute A mp
3 CH1_IN(+) Channel 1Balanced Input (+)
5 N/ C Not Used
7 CH2_IN(+) Channel 2 Balanced Input (+)
9 GND Connect to Power Supply GND
Pin Si g nal D esc r ip t i o n
2 CLIP_N Clip Indicator
4 CH1_IN(-) Channel 1Balanced In(-)
6 N/ C Not Used
8 CH2_IN(-) Channel 2 Balanced In(-)
10 OTW_N Over-Temp Warning
