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Issue 1
A120 MODULAR AMPLIFIER
The A120 is a modular amplifier mainframe that can accept up to 8 input modules and 1
output module to suit most Public Address requirements.
The A120 can be either mains (230V) or battery (24V) operated, and can be fitted with an
internal 1 amp battery charger AC1A (optional).
Preparation for Use
AC Supply
Connect to mains socket on rear of amplifier using the lead supplied.
IMPORTANT: This equipment must be earthed.
Loudspeaker Output
DC Supply Input (battery)
The amplifier provides connections
23V – 30V DC. Note: Negative Earth
for either 100V or 50V line
Sub-Socket
The sub-socket found on the rear of the unit can be used for a variety of purposes: tape
recording, feeding other Adept amplifiers, feeding mixers, operating busy lamps, relays etc.
Pin 1
Provides 500mV signal output for
driving slave amplifiers or a tape recorder.
This output is direct from the power amplifier
input and after the master gain and tone
controls.
Pin 2
Output Signal Ground
Pin 3
As pin 1 but signal is derived prior to master gain and tone controls. Output impedance
10K ohms.
Pin 4
Open collector ‘busy’ indicator: 0V switched output used in conjunction with pin 5.
Pin 5
1A fused DC output at +24V, used in conjunction with pin 4 to provide an electrical
relay control supply for zoning purposes, priority circuit indicators or DC power for an
external tuner or signal processing and line pre-amplifiers.
