Pertronic Industries Ltd
2 of 2 0323 50W Amplifier Preamp Iss 3.1 20160927
Microphone Connection:
A microphone is connected to the 50W Amplifier Preamp as shown below. Terminals are
provided for the microphone, push-to-talk switch, and cable shield. Connect the wires ensuring
that the micrve wire is connected to the 50W Amplifier Preamp’s +ve input, and the
microphone
–ve wire to the 50W Amplifier Preamp’s -ve input.
Ensure that the cable shield is connected to the shield input. Leaving the shield unconnected
will impact on the quality of the signal received. The shield
must not
be connected to panel
earth as this will also reduce the quality of the signal received by the 50W Amplifier Preamp.
Fig2. Microphone Wiring
Line Connection:
A 100 mVrms line input is provided if a remote preamplifier is desired. Connect the wires
ensuring the line +ve wire is connected to the Line + input, and connect the Line
–ve wire to
the ‘SHLD, L-‘ input. If the line audio cable has a shield, also connect this to the ‘SHLD, L-‘
input.
Links are provided to select the required microphone operation. Install the “Fire link” to select
Fire Microphone mode. To select PA mode install the PA link jumper. As a rule of thumb, if the
microphone is to be used by the occupants of the building, then set the jumpers to PA mode.
The sensitivity of the 50W Amplifier Preamp is set to maximum by default. If distortion occurs,
or the volume simply needs reducing, a volume pot is provided.
Specification:
Microphone Input Sensitivity:
1.5 mVrms
– 15 mVrms
Microphone Input Impedance:
680 ohm
Line Input Sensitivity:
100 mV
– 1.5 Vrms
Line Input Impedance:
68K ohm
Frequency Response:
400 Hz to 20 KHz
Current Consumption:
< 1 mA
Recommended Cable:
0.2 mm
2
4-core twisted wire shielded audio cable
Maximum length:
5 meters maximum
Maximum Daisy Chained Mic Inputs:
4
Maximum Daisy Chained Line inputs:
10
Compatible 50W Amplifier Hardware:
v2.02 and above
Compatible 50W Amplifier Software:
v1.80 and above
Product Code
Description
EVAC50PREA
Pre-Amp (Mic I/P) for EVAC50W24V Amplifier, SMD version
