Input Combine; Adjusting Input Gain; High Mass Internal Heatsink; Ap-Iv Protection Circuit - Directed Electronics Precision Power A1200/4 Owner's Manual

INPUT COMBINE

Your multi-channel amplifier can use both front and rear outputs
from your head unit to maintain the ability to fade front to rear, or you
can run a single set of RCAs to the front inputs and push in the Rear
Input INT/EXT switch on the amplifier endplate to route the front
signal to the rear channels as well.

ADJUSTING INPUT GAIN

1. Adjust all amplifier input gain controls to just above minimum
sensitivity (fully counterclockwise).
2. Using the cleanest music source (CD) playing, turn up the head
unit source volume until you can hear distortion. Now turn it down a
bit until you cannot hear the distortion (usually just below full
volume).
3. Increase the amplifier gain (clockwise) until the onset of audible
distortion. Then decrease the gain to the point just before the
distortion starts. This setting minimizes background noise and
prevents overload.
4. Repeat step 3 for any remaining independently controlled
amplifiers (rear and subwoofer gain controls) in the system.

HIGH MASS INTERNAL HEATSINK

The unique heatsink on your amplifier has been designed with fins
on the inside of the aluminum extrusion. This allows for the transfer
of heat from the circuitry to the heatsink fins and out through the
vents in the endplates. Be sure you provide ample space around the
amplifier for cooling: at least 2" on all sides.

AP-IV PROTECTION CIRCUIT

Short Circuit Protection engaged: These amplifiers will turn off and
try to come back on immediately (the status LEDs will flash). The
amplifier will cycle like this indefinitely with "blips" of sound each
time. If this is the case, check your speakers and wiring for low
impedance and short circuits.
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