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Bridge mono dual parallel mono – Crown Audio Com-Tech "10 Series" User Manual

Page 17

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Page 17

Com-Tech Power Amplifiers

Reference Manual

Fig. 3.6 Wiring for Bridge-Mono 70-Volt Mode (140-Volt Output)

COM

+

+

140 VOLT STEP-DOWN

TRANSFORMERS

16, 8, OR 4 OHM

16, 8, OR 4 OHM

140 VOLT LINE

MIXER

LOUDSPEAKERS

Com-Tech Amplifier

CHANNEL 1

BRIDGE-MONO
70 VOLT MODE
(140 VOLT OUTPUT)

TURN OFF THE AMPLIFIER

BEFORE CHANGING

THE DUAL/MONO SWITCH.

TURN OFF THE AMPLIFIER

BEFORE CHANGING THE

OUTPUT MODE SWITCHES.

WARNING: BOTH CHAN-

NELS MUST BE SET TO

70 VOLT MODE.

COM

+

+

DO NOT

USE

TURN OFF CHANNEL 2 (CCW)

IN BRIDGE-MONO MODE.

DO NOT USE

THE GROUND

TERMINALS

BRIDGE

MONO

DUAL

PARALLEL

MONO

70

VOLT

70

VOLT

8/4

OHM

8/4

OHM

CH1

CH2

CH-2

CH-1

0

dB

.5

1

2

3

4

5

6

7

8

9

10

11

13

15

17

19
21
25

32

0

dB

.5

1

2

3

4

5

6

7

8

9

10

11

13

15

17

19
21
25

32

PR

ESS

R E S E

T

PUSH TO RESET

BB

CH2

CH1

+

+

Programmable
Input Processor (P.I.P.)

REMOTE

WARNING: Both channels must be configured for
the same output mode (8/4-ohm or 70-volt) before
switching to Bridge-Mono mode.

Bridge-Mono wiring is very different from the other
modes and requires special attention. First, turn the
amplifier off. Then select Bridge-Mono mode by sliding
the dual/mono switch to the BRIDGE MONO (right) po-
sition. Both outputs will receive the signal from Channel
1 with the output of Channel 2 inverted so it can be
bridged with the Channel 1 output. DO NOT USE THE
CHANNEL 2 INPUT or the signal level and quality may
be greatly degraded. Also, keep the Channel 2 Input
Attenuation control turned down completely (counter-
clockwise).

Note: The Channel 2 input jack and Input Attenuation
control are not defeated in Bridge-Mono mode. A signal
feeding Channel 2 will work against the Channel 1 sig-
nal, and usually results in distortion and inefficient op-
eration.

Connect the load across the two positive (+) output ter-
minals (see Figure 3.6 and the middle illustration in Fig-
ure 3.7). The positive lead from the load connects to the
positive Channel 1 terminal, and the negative (or
ground) lead from the load connects to the positive

Channel 2 terminal. Do not connect the output
grounds ( ). Also, the load must be balanced (neither
side shorted to ground).

CAUTION: Connect only balanced equipment
(meters, switches, etc.) to the Bridge-Mono output.
Both sides of the line must be isolated from the in-
put grounds or oscillations may occur.

BRIDGE

MONO

DUAL

PARALLEL

MONO

P A R A L L E L - M O N O

Parallel-Mono mode is used to drive loads with a total
impedance of less than 4 ohms when using 8/4-ohm
output mode (see

Bridge-Mono if the load is greater

than 4 ohms). This mode can also be used to drive a
single high-powered 70-volt constant voltage line.

Parallel-Mono installation is very different from the other
modes and requires special attention.

WARNING: Both channels must be configured for
the same output mode (8/4-ohm or 70-volt) before
switching to Parallel-Mono mode.