Wiring For Dual 70 Volt Mode - Crown Com-Tech CT-210 Reference Manual

uted loudspeaker system, the constant voltage output
varies with the output power rating of the amplifier. With
8/4-ohm output in Dual or Parallel-Mono mode, the
Com-Tech 210 can drive a 25-volt line, the Com-Tech
410 can drive a 35-volt line, the Com-Tech 810 can drive
a 50-volt line, and the Com-Tech 1610 can drive a 70-
volt line. Using Bridge-Mono mode, these voltage lev-
els are doubled for a single channel. Again, to
effectively use different constant voltage levels, you may
need to cross reference the ratings for the step-down
transformers' taps using Crown's constant voltage com-
puter (see Section 8.3).
D U A L
Dual mode allows each amplifier channel to operate in-
dependently like a "dual mono" or stereo amplifier. And
if you select both Dual mode and 70-volt output, each
output channel can drive a 70-volt line. Installation is
intuitive: Input Channel 1 feeds output channel 1, and
input Channel 2 feeds output Channel 2.
To put the amplifier into Dual mode, turn it off, slide the
dual/mono switch to the DUAL (center) position, and
properly connect the output wiring. Be sure to observe
MIXER
Com-Tech Amplifier
DUAL 70 VOLT MODE
(BOTH CHANNELS)
Page 16
CHANNEL 1
CHANNEL 2
BB
REMOTE
CH2
PUSH TO RESET
+ –
Programmable
Input Processor (P.I.P.)
10 9
11 8
13 7
15 6
17 5
19 4
21 3
25 2
32 1
.5
dB 0
CH-2
DUAL
TURN OFF THE AMPLIFIER
PARALLEL BRIDGE
BEFORE CHANGING
MONO MONO
THE DUAL/MONO SWITCH.
Fig. 3.5 Wiring for Dual 70-Volt Mode
correct loudspeaker polarity (see Figure 3.4) and be
careful not to short the two outputs.
CAUTION: Never tie an amplifier's outputs together
directly while in dual mode. Never parallel them with
the output of another amplifier. Such connections do
not result in increased output power, but may cause
overheating and premature activation of the protection
circuitry.
Note: To parallel multiple amplifiers for fail-safe redun-
dancy, contact Crown's Technical Support Group.
B R I D G E - M O N O
Bridge-Mono mode is used to drive loads with a total
impedance of at least 8 ohms (see Parallel-Mono if the
load is less than 4 ohms). If Bridge-Mono mode and 70-
volt output are used together, twice the normal output
voltage is produced from a single channel to drive 140-
volt distributed loudspeaker systems. If you will be us-
ing 140-volt output, you may need to cross-reference
the ratings of the step-down transformer taps with
Crown's constant voltage computer (see Section 8.3). If
you need a single channel with higher power to drive a
70-volt line, use Parallel-Mono mode.
8/4 70 8/4 70
OHM VOLT OHM VOLT
CH2 CH1
CH1
+ –
10 9
11 8
13 7
15 6
17 5
19 4
21 3
25 2
32 1
.5
dB 0
CH-1
CHANNEL 1
70 VOLT LINE
CHANNEL 2
Com-Tech Power Amplifiers
TURN OFF THE AMPLIFIER
BEFORE CHANGING THE
OUTPUT MODE SWITCHES.
+ +
16, 8, OR 4 OHM
–
COM
70 VOLT STEP-DOWN
LOUDSPEAKERS
TRANSFORMERS
–
COM
16, 8, OR 4 OHM
+ +
Reference Manual