Specifications

Page 17
D-45 / D-75A Power Amplifiers
Fig. A.1 Main Circuit Board (Component Side)—Jumper and Resistor
Locations for Input Sensitivity and Dual/Mono Modes
Appendix A
A.1 Internal Settings
From the factory, your amplifier is configured for dual
(stereo) operation and an input sensitivity of 26 dB gain.
You may optionally configure the unit for higher-power,
single-channel, bridge-mono operation. Also, the unit
can optionally be set for an input sensitivity of 0.775
volts. To configure the unit for bridge-mono operation
or 0.775 volt input sensitivity, the chassis of the unit must
be opened.
WARNING: Risk of electric shock! Turn off the am-
plifier and disconnect its power cord from the AC
mains before opening the amplifier chassis.
CAUTION: Only a qualified technician should at-
tempt to change the amplifier’s internal settings.
A.1.1 Opening the Amplifier Chassis
Before undertaking this procedure, please read Appen-
dix A.1.2 and A.1.3 to help determine whether you need
to alter the amplifier’s internal settings, and whether you
want to handle these procedures yourself.
1. Turn the amplifier off and disconnect its power
cord from the power receptacle.
2. Remove the six screws that hold the top cover in
place. (There are three screws on each side of
the unit.)
3. Remove the nine screws that fasten the bottom
cover to the chassis. This will expose both sides
of the main circuit board.
A.1.2 26 dB Gain vs. 0.775 Volt Input Sensitivity
For most applications, the amplifier’s default setting of
26 dB gain will be ideal. With this default setting, full
output power is achieved with an input signal of
0.632 volts for the D-45 , and 0.837 volts for the D-75A .
Some applications may require the gain structure to be