Madrigal Imaging BPA 3 - Manual (Page 15)

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5 BALANCED AUDIO INPUTS
Accepts right-channel and left-channel signals from preamplifiers with bal-
anced outputs via high quality XLR connectors.
The pin assignments of these XLR-type female input connectors are:
Pin 1: Signal ground
Pin 2: Signal + (non-inverting)
Pin 3: Signal – (inverting)
Connector ground lug: chassis ground
These pin assignments are consistent with the standards adopted by the
Audio Engineering Society. Refer to the operating manual of your balanced-
output preamplifier to verify that the pin assignments of its output connec-
tors correspond to your Proceed BPA. If not, wire the cables so that the ap-
propriate output pin connects to the equivalent input pin.
If you are planning to use balanced connections between your preamplifier
and any particular channel of the BPA, select the balanced input by sliding
the
input select switch (see Item 6, below) toward the XLR input. Then
connect the balanced outputs of your preamplifier to the corresponding
balanced inputs on the BPA.
6 INPUT SELECT SWITCH
This small switch is found between the balanced XLR input and the single-
ended RCA input on each channel of the BPA. Use it to select which of the
two inputs you plan to use.
The input select switch disables the unselected input in order to avoid any
pickup of stray noise from an open input. It also causes the effective gain
of that channel to be adjusted (either 23 dB balanced or 29 dB single-
ended, to compensate for the 6 dB difference in signal level in these two
connection standards). Should you use your BPA in a home theater system,
this adjustment allows you to use any combination of balanced and single-
ended connections without having to worry about going outside the adjust-
ment range of your controller’s output calibration circuitry.
7 SINGLE-ENDED INPUTS
These RCA connectors accept single-ended inputs from preamplifiers with
single-ended (RCA) outputs.
Connect the left-channel single-ended outputs of your preamplifier to the
left-channel single-ended input on the BPA. Repeat for the remaining
channel(s).