SI-125 Power Amplifier Manual
2
Unit Description
The various amplifier parts are:
Figure 1: SI-125 Front View
A.
VU METER:
The 30 dB digital VU meter shows 0 dB when the amplifier is operating at
its rated output. Exceeding the rated output will cause the output to be clipped, which will
be indicated by the illumination of the CLIP light.
B.
HIGH TEMPERATURE Light:
If the internal temperature of the amplifier exceeds its
normal operating limit, the High Temperature light will illuminate and the output level
will begin to be reduced. The amplifier will continue to operate at a reduced output level
until the temperature returns to an acceptable level. If the High Temperature light
illuminates, see the Troubleshooting section.
C.
CURRENT OVERLOAD Light:
If the current output of the amplifier exceeds its
maximum power output, the Current Overload light will illuminate and the output level
will begin to be reduced. The amplifier will continue to operate with the current limiting
circuit reducing the output power. If the Current Overload light illuminates, see the
Troubleshooting section.
D.
GAIN Control:
The gain of the amplifier can be adjusted using this potentiometer. The
potentiometer is concealed behind a snap-on cover. The cover can be snapped off when
the level needs to be adjusted but should be replaced to prevent unintended tampering.
The amplifier gain is set by both this control and the sensitivity Input Level switch on the
back of the amplifier.
E.
POWER Switch:
Turns the amplifier on and off. The switch will illuminate when the
amplifier is turned on.
Figure 2: SI-125 Rear View
