Do not use XLR and TRS jacks on the same channel simultaneously
for mixing or other purposes.
Figure 6. Balanced line
To use an unbalanced source, connect pin 3 (ring on TRS jack) to the
shield of the connector. If you leave one pin disconnected, you will lose
6dB in gain.
Figure 7. Unbalanced line connection
A better method for using unbalanced sources is shown in Figure 8. This is
similar to the connection for balanced lines, but pin 3 is connected to the
shield at the source. The hum and noise rejection for the cable is
equivalent to that for a balanced line. To minimize hum in the audio, use
balanced inputs whenever possible.
Figure 8. Balanced line with unbalanced equipment
Martin Audio – MA2.8 Power Amplifier
E
NGLISH
10
1
2
3
1
2
3
2
1
3
Balanced Output
Balanced Output
Amplifier Input
Amplifier Input
Signal
Grounded
Shield
2
1
3
Chassis
Grounded
Shield
1
2
3
1
2
3
2
1
3
Unbalanced Output
Unbalanced Output
Amplifier Input
Amplifier Input
+
+
–
–
1
2
3
1
2
3
2
1
3
Unbalanced Output
Unbalanced Output
Signal
Grounded
Shield
Amplifier Input
Amplifier Input
+
+
–
–
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