Crown DC-300A Instruction Manual page 28

29
DC-300A MONO CONVERSION
APPLICATION NOTE NO. 2
A. Access to circuit board
1. Remove screws (4 top and 4 bottom) mounting top
and bottom covers to front panel.
2. Remove mounting screws (2 each end) connecting
front panel to heat sinks.
3. If front panel will move more freely, proceed to
step 4. If front panel is still, contacting the heat
sinks at both ends, loosen screws in top and bottom
covers to free front panel.
4. Carefully lift the front panel straight out from be-
tween the heat sinks, being careful not to tilt the
panel in any direction until it is free of the amp,
and also being careful not to scratch the interior
surface of the rack mounting bars with the front
panel ends.
5. Set the panel down carefully to avoid scratching
it or straining the level control cables by which
it remains attached to the amplifier.
B. Wiring changes
1. On the exposed circuit board, locate printed
circuit sockets A, B, C, and D (Fig. 1), being
careful to distinguish them from other sockets
on the board.
2. Mount a 214" length of insulated hookup wire (%4"
of insulation stripped from each end) by inserting
the ends into sockets A and B. (This operation
grounds the channel 2 input.)
3. Mounta10K , 1% tolerance, "% watt resistor with
insulated leads by inserting the lead ends into
sockets C and D. (This feeds the channel 1 output
signal into the channel 2 inverting input.)
O tn Hook
10K, 15, % watt
Resistor leads
Insulated
Top (Component) side of board
MONO CONVERSION
Fig. 1
C. Reassembly: reverse the procedure of step A.
D. Operation
1. Make output cable as shown in Fig. 2.
2. Connect one lead to HOT (red) amplifier output
post of channel 1, the other lead to HOT output
post of channel 2.
CAUTION: DO NOT CONNECT EITHER HOT
OUTPUT TO GROUND (EITHER BLACK POST).
POWIR INPUT CABLE
cape
LINE FUSE
Fig. 2
E. Performance Specifications
See Page 2A