Specifications subject to change. | ©2021 Procella Audio Svenska AB, Procella Audio USA, LLC. All rights reserved. | V1.0 2021/08 5
Configuration and Installation
4. Configuration
The Procella DA4280 amplifier operational configuration is set up
through selections made on a rear mounted DIP switch module.
A GPIO (General Purpose In/Out) connector is also provided that
enables some amplifier functions to be controlled or monitored
remotely.
4.1 DIP Switch Configuration
The DIP switch module is illustrated and its
functions described in the adjacent matrix.
DIP switch options are selected (ON) when
the switch is in the UP position. DIP switches
should only be operated when the amplifier
is disconnected from mains power.
Note: Use a small flat blade screwdriver
blade to operate the DIP switches.
Note: Channels operating in Hi-Z mode
have a 80Hz second order (12dB/octave)
high-pass filter automatically inserted
into the signal path in order to prevent
speaker transformer core saturation.
OFF
ON
SWITCH 1
Channel 1 in Low-Z mode
Channel 1 in Hi-Z mode
SWITCH 2
Channel 2 in Low-Z mode
Channel 2 in Hi-Z mode
SWITCH 3
Channel 3 in Low-Z mode
Channel 3 in Hi-Z mode
SWITCH 4
Channel 4 in Low-Z mode
Channel 4 in Hi-Z mode
SWITCH 5
70V Hi-Z mode
(for channels in Hi-Z mode)
100V Hi-Z mode
(for channels in Hi-Z mode)
SWITCH 6
Input ganging 1: All
Input ganging 1:1
SWITCH 7
GPIO standby polarity NO
(Normally Open)
GPIO standby polarity NC
(Normally Closed)
SWITCH 8
Front panel control locked.
Front panel control unlocked.
4.2 GPIO Functions
The GPIO connector
is illustrated and its
functions described in
the adjacent matrix.
Note: The GPIO
connector must
not be used for any
unintended purpose.
Amplifier damage may
result from incorrect
use of GPIO.
Note: In order to
conform to EMC
specifications,
shielded cable must
be employed when
connecting external
volume control
potentiometers to the
GPIO connector.
FUNCTION
NOTES
GPIO GND (1)
Ground reference for all GPIO pins
GPIO V12 (2)
Channel 1 & 2 auxiliary gain control.
Connect to a potentiometer (>10kΩ)
wiper between the VCC and GND pins.
The maximum level available when
using GPIO control is defined by the
front panel gain control setting.
GPIO V34 (3)
Channel 1 & 2 auxiliary gain control
(four channel amplifier only).
Connect to a potentiometer (>10kΩ)
wiper between the VCC and GND pins.
The maximum level available when
using GPIO control is defined by the
front panel gain control setting.
GPIO VCC (4)
Control voltage output.
Provides a 3.3Vdc control output
(100Ω output impedance) for up to
two volume control potentiometers
(>10kΩ).
GPIO STB (5)
Remote standby control.
Pull to GND to engage standby mode.
GPIO GPO (6)
System status indication.
OV DC indicates normal status, +3.3Vdc
indicates one or more channels in
protection mode.
1
2
3
4
5
6
