Alto APM80.1000 Service Manual page 27

a). Adjust the AC voltage, make AC output is equal to 230V, the power supply switching
switch indicates the 230V position, two output channels of the amplifier connection with 4
ohms loads, input -20dBu signal from CH1, adjust the LEVEL and the waveform of the
oscilloscope undistorted, at that time to test the maximum value of the amplifier can
output.
b). Adjust the AC voltage, make AC output is equal to 115V, the power supply switch
indicates the 115V position, two output channels of the amplifier connection with 4 loads,
input -20dBu signal from CH1, adjust the LEVEL, make the waveform of the oscilloscope
undistorted, at that time to test the maximum value of the amplifier can output.
1. AMPLIFIER MODE is the MAIN+MAIN status, the outputs of the amplifier are:
APM80.1000: >60V. (Amplitude value)
APM80.1500: >68V. (Amplitude value)
2. AMPLIFIER MODE is the MAIN+ MONITOR status, the outputs of the amplifier are:
APM80.1000: >60V. (Amplitude value)
APM80.1500: >68V. (Amplitude value)
3. AMPLIFIER MODE is in the bridge status, at that time, the load is 8 ohms.
APM80.1000: >108V. (Amplitude value)
APM80.1500: >128V. (Amplitude value)
9. Signal Noise Test:
a). Turn all the LEVEL GAIN to the minimum, and turn the GAIN of the MAIN and MONITOR
knobs to the maximum, at this point, the curve of the amplifier output (LEFT, RIGHT) is
as follows:
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