SI-125 Power Amplifier Manual
4
Clipping
Output Clipping
is the point where the peak output signal is limited to avoid damage to the
amplifier from excessive output current (current overload). Once output clipping is detected, any
increases in input level will not cause increases in output level (this is shown by the output
plateau in Figure 4). To avoid distortion, the output signal is dynamically attenuated to give the
maximum attainable output voltage without distortion, although technically the peak output level
is clipped at this point. The Current Overload light will turn on when the current limiting
circuitry is engaged.
Figure 4: Effect of Clipping
Input Attenuation
will occur when the signal is limited due to excessively high signal level at
the input. The clipping LED will turn on either when there is excessive signal level on the input
or when there is hard clipping present on the output. The CLIP light will not turn on when the
output level is clipped due to current overload.
Installation
Before installing an SI-125 Power Amplifier, carefully inspect the device for any damage that
may have occurred during shipping. The shipping package should contain only the Power
Amplifier. If any part of the amplifier has been damaged, please contact the shipping company as
soon as possible.
DO NOT ATTEMPT TO INSTALL EQUIPMENT THAT WAS RECEIVED
DAMAGED.
The amplifier mounts into a standard 19" Telecor equipment rack with 10-32 screws. The SI-125
requires 5 ¼" of vertical rack space. When mounting the amplifier into a rack with other
equipment, be sure to allow for adequate ventilation. To accomplish this, ensure that a blank
panel of 1 ¾" height (or greater) is installed between the amplifier and any other equipment (e.g.
additional amplifiers, power supplies, etc.) in the rack.
