dbx 120A - Manual (Page 15)

Wiring Diagrams
7
120A
120A User Manual
A.3 Installation Considerations and Wiring Diagrams
The 120A has 1/4”, balanced/unbalanced inputs and is designed for nominal +4dBu levels. The 120A also offers RCA
connectors, and is designed for nominal -10dBV levels.
Input Cable Configurations
The 120A will accept either balanced or unbalanced sources as long as cables are wired according to the following
diagrams. In an emergency, 1/4” mono cables will work. Connect the sleeve to the cable’s shield. Note: for maxi-
mum hum rejection with a balanced source, avoid common grounding at the 120A’s input and output. The best start-
ing point is to ground the shield of the input cable at the source device (leaving it unconnected at the 120A).
Output Cable Configurations
The 120A will drive either balanced or unbalanced loads as long as the cables are wired according to the following
figures. The output’s impedance at 100
Ω, allowing operation with virtually any load. Nominal operating level is
+4dBu into 600 Ω. If using 1/4” mono plugs, at the output, the 120A will be grounded to the load device. This can
cause a ground loop. By using 1/4” balanced phone plugs, the grounds of both the 120A and the load can be isolat-
ed to reduce hum. Leave the shield unconnected at the load device.
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Appendix