Proceed HPA2 User Manual
Page 15
15
Note:
If the DC trigger input is used to control the amplifier(s), the
last mini-jack in the chain must be filled with a dummy
1
⁄
8
"
plug [that is, an empty plug must be inserted into the final
1
⁄
8
"
[3.5 mm] jack]. Even if only a single amplifier is controlled in
this fashion, the “extra” mini-jack must be filled with a dummy
plug.
If you are not using these turn-on inputs, you may leave them both empty
of any plugs.
4
BALANCED AUDIO INPUTS
Accepts signals from preamplifiers with balanced outputs via high quality
XLR connectors.
The pin assignments of these XLR-type female input connectors are:
PUSH
2 1
3
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 amplifier. If not, wire the cables so that the
appropriate 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 amplifier, select the balanced input by
sliding the
input select switch
(see Item 5, below) toward the XLR input.
Then connect the balanced outputs of your preamplifier to the correspond-
ing balanced inputs on the amplifier using high quality cables such as CZ
Gel-1.
5
INPUT SELECT SWITCH
This small switch is found between the balanced XLR input and the single-
ended RCA input on each channel of the amplifier. 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 what would otherwise be an open input. It also
causes the effective gain of that channel to be adjusted (either 23 dB bal-
anced or 29 dB single-ended, to compensate for the 6 dB difference in sig-
nal level in these two connection standards). Should you use your amplifier
in a home theater system, this adjustment allows you to use any combina-
tion of balanced and single-ended connections without having to worry
about going outside the adjustment range of your surround decoder’s out-
put calibration circuitry.