Bogen C10B User Manual

ISI

A LEAR SIEGLER COMPANY

PUBLIC ADDRESS
AMPLIFIERS Models C10B&C20B

DESCRIPTION

The Bogen Mudels ClOB iuiU C20B sulid-stale public address
amplifiers are rated at 10 watts and 20 watts, respectively, and
are UL and CSA listed.

The units will accommodate most microphone types, offering

the capability for both high impedance and low impedance

microphones. A front panel selector switch allows one of the two
microphone channels (MIC 2) to be used as an auxiliary input,
which can be muted when a customer-supplied SPST normally-

opcii switch is used foi [iiiciuphuiic precedence.

Independent volume controls and a treble control, for adjust

ment of tonal balance, are provided.

Balanced or unbalanced outputs are provided for 4, 8, and 16
ohm speakers, and 25 volt constanl-vollage systems. A terminal
strip with screw terminals allows convenient connection of
speakers, except 70 volt. For 70 volt operation, a quick-disconnect
speaker socket is provided.

The ClOB and C20B amplifiers operate from a 120 volt, 60 Hz

source and have a maximum power consumption of 46 and 60

watts, respectively. A thermostat, enclosed in the power trans

former, protects the unit against overloads.

TECHNICAL SPECIFICATIONS

ClOB

POWER OUTPUT:

FREQUENCY RESPONSE:

HUM AND NOISE:

(20 - 20kHz)

SENSITIVITY:

OUTPUTS:

OUTPUT CONNECTIONS:

INPUT CONNECTIONS:

CONTROLS

TONE CONTROL ACTION

POWER REQUIREMENTS

SEMICONDUCTORS

DIMENSIONS

WEIGHT

10 watts

4, 8, 16 ohms

25V (62.5 ohms)

70V (500 ohms)

Screw-type terminals for 4, 8, 16 ohm and 25V tap

2 MIC HI-Z jacks/2 MIC LO-Z terminals, AUX HI-Z jack,

120 VAC 60 Hz

46 watts

5 lbs. (2.27 kg) 6 lbs. (2.7 kg)

INSTALLATION

UNPACKING

The amplifier was carefully checked before leaving the factory.
Inspect shipping container and unit carefully for indication of
improper handling: if the unit has been damaged, make an
immediate claim to distributor from whom it was purchased, or if
the amplifier was shipped directly to you, notify the carrier without
delay and place your claim.

POWER AND GROUNDING

The ac line cord has a three-prong plug which should be

plugged Into a three-wire grounded, 120 volt, 60 Hz outlet. Since it

is important to ground the amplifier, where a three-wire outlet is
not available, use an adapter (e.g., Levitón No. 5017) and connect
the grounding pigtail to the screw securing the wall plate. If the
wall plate screw is not grounded, connect a wire from the GND
terminal of the amplifier to a water or steam pipe.

C20B

20 watts

80 to 10,000 Hz ±2dB

MIC Input SSdB below rated output

AUX Input 70dB below rated output

MIC HI-Z Input 3mV

MIC LO-Z Input 300/iV

AUX Input 250mV

4, 8, 16 ohms

25V (31.3 ohms)

70V (250 ohms)

Quick-disconnect socket for 70V tap

500/600 line with WMT-1 accessory*

MIC 1, MIC 2/AUX, Treble control

Treble: lOkHz-lldB

120 VAC 60 Hz

60 watts

All Silicon — 11 Transistors, 5 Diodes

1 iys"W X 276"H X 7y"D (28,9 x 7,3 x 19.7 cm)

‘MIC 2/AUX are switch-selectable.

AUXILIARY POWER

S-X The auxiliary power receptacle on the rear chassis is a three-wire

grounded outlet, which can supply power to accessory or associated
equipment in the sound system. Be sure that the auxiliary
component does not draw more than 300 watts. The power switch
on the front panel of the amplifierdoes not control this receptacle.

Equipment connected to this receptacle will remain on at all times
unless turned off with its own On/Off switch.

Associated equipment connected to the auxiliary receptacle
with a three-prong line cord will be grounded, providing the
amplifier line cord has been properly grounded, as previously
described. Otherwise, it may be necessary to ground the auxiliary
equipment.

INPUT CONNECTIONS

AMPLIFIER I

6ND COM 16 JL

A74-2090-0I

AMPLIFIER 2

6ND COM t6.TL

ClOB

MICROPHONE: Connect low impedance microphones to the
input screw terminals on the rear panel. High impedance
microphones should be connected to the input jacks provided.

MICROPHONE PRECEDENCE; A built-in circuit provides
muting over the MIC 2/AUX channel. This is achieved by
connecting a customer-supplied SPST normally-open switched
microphone cable to the MIC 2/ AUX MUTE screw terminals.

AUX: To connect a turntable (with ceramic cartridge) to the AUX

jack, use a single-conductor shielded cable terminated in a

standard RCA phono plug. It is recommended that a separate
ground wire be connected between the turntable base and the
amplifier GND terminal to minimize hum pick-up.

The AUX input may also be used for any other signal source
having a high level (.15V) output, such as the Bogen Model
TP50 FM/AM Tuner.

Connecting Low-Impedance Unbalanced Microphone Inputs

-A

-----

-R-

®

\J ^è—3_

MIC z

MIC

AMPLIFIER I

GND COM 0il

Figure 2 — Connecting Amplifiers in Series

AMPLIFIER 2

GNO COM 8A

OUTPUT CONNECTIONS

SPEAKERS: The amplifier may be used with speaker systems
rated at 4, 8 and 16 ohms and with 25-volt and 70-volt constant
voltage systems. For detailed information on the installation of
multiple speaker systems, refer to the Speaker Installation

Instructions (No 54-5001).

Connect the speaker system directly to the speaker output
terminals on the rear of the amplifier. Connect one speaker lead to
the COM terminal and the other to the terminal corresponding to

the impedance of the speaker system For balanced output lines,

remove the link between COM and GND output terminals. If the
line is shielded, connect the shield to GND. The 70V output is
available only through the 3-pin connectors.

Connecting High-Impedance Microphone Inputs

HI-* MIC

BOGEN PL-I /

SWITCHCRAFT WO. 445

A7+-4.1SS -01

Figure 1 — Comiecting Microphone Cables

„

_______

□)

To minimize shock hazard. Class 1 wiring as

Caution

defined in iocai building codes should be used

for 70-volt outputs. Ml other outputs may use

Class 2 wiring.

CONNECTING AMPLIFIERS IN SERIES

Pairs of Bogen ClOB or C20B amplifiers can be connected in
series to effectively double the power output into the same speaker

system. See figure 2 for eonnection diagram. Be certain to remove

the link between COM and GND of amplifier No. 2, Note that this
arrangement is for unbalanced speaker lines. For balanced lines
also remove the link between COM and GND of amplifier No. 1.

The input cabling must be arranged to parallel the inputs of the

two amplifiers, and the volume and tone controls of both

amplifiers must be at the same setting to assure that each amplifier
will share the load equally.