Input Wiring; Balanced Operation - Bose 1800-VI Owner's Manual

4.0 Installation

4.6 Input wiring

You may use 1/4" phone jacks, XLR connectors, and quick connect terminal block
connectors for the input signal with either unbalanced 2-conductor or balanced
3-conductor cables. Use shielded coaxial cable to conduct the signal from the
source (mixer, equalizer, CD player) to the amplifier.

4.6.1 Balanced operation

For the 1/4" phone jack, use a 3-conductor TRS 1/4" phone plug. The tip of the plug
carries the + (hot, non-inverting) side of the signal. The ring carries the – (low, inverting)
side of the signal. The sleeve is ground (see Figure 1).
For the XLR, use a male XLR connector. Pin 2 carries the + (hot, non-inverting) side of the
signal. Pin 3 carries the – (low, inverting) side of the signal. Pin 1 is ground (see Figure 2).
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Figure 1
1/4" phone jack balanced input
connection.
Figure 2
XLR balanced input connection.