Bogen CAM User Manual

C O M M UIM1C A T10 N S, 1N C.

MIXER-PREAMPLIFIER

Model CAM is a fully transistorized mixer-preamplifier
providing four microphone inputs and one auxiliary input, and
supplying both microphone and high level outputs. While it
fulfilLs a wide variety of applications, the CAM is particularly
well suited for expanding the number of inputs of Bogen public
addre.ss amplifiers.

The CAM accommodates both high and low impedance
microphones, and has an input for crystal or ceramic cartridges,
tuners or other high level sources. Outputs are provided for high
impedance unbalanced or low impedance balanced or un
balanced microphone inputs and high level, high impedance
inputs to a public address amplifier, tape deck or similar
equipment. Units may be paralleled to provide a greater
number of inputs.

The CAM operates from either 120VAC, 60Hz or 25-28VDC
source. It may be mounted in a standard 19" equipment rack using
Bogen RPK35B Rack Mounting Kit or in a wall with Model
WMK-l In-^II Mounting Kit.

INSTALLATION

UNPACKING

Your unit was carefully checked before leaving the factory.
Inspect the shipping container and the unit carefully for
indications of improper handling. If the unit has been damaged,
make an immediate claim to the distributor from whom it was
purchased. If it was shipped to you, notify the transportation
company and place a claim.

POWER and GROUNDING

The AC line cord has a three-prong plug which should be
plugged into a three-wire, grounded 120V. 60 Hz outlet. If a
three-wire outlet is not available, use an adapter and secure the
pigtail lead to the grounded wall plate mounting screw. Ii is
important to ground the unit. If the wall plate screw is not
grounded, connect a wire from the GND terminal of the
mixer/preamplifier to a suitable earth ground.

Auxiliary power

A 24 to 28V external DC supply may be used to power the
unit and may remain connected when the unit is being powered
by the primary AC source. The power switch, when set to off,
disconnects both AC and DC supplies, turning the unit off.

Model CAM

INPUT CONNECTIONS

HIGH IMPEDANCE MICROPHONES

High-impedance microphones (approxiraately 20K to 50K
ohms) may be connected to any of the four MIC inputs. The
microphone lead should be a single-conductor shielded cable
terminated in a standard 3-pin microphone connector (Cannon
XLR-311C, or equivalent). See figure 1.

LOW IMPEDANCE MICROPHONES

Model CAM will also accommodate low impedance micro

phones directly. Use two-conductor shielded cable terminated in

a standard 3-pin microphone connector, as shown in figure 1.

AUXILIARY INPUT

One auxiliary input is provided for high-level, high­impedance inputs, such as a radio tuner, tape player, or
turntable utilizing a ceramic cartridge. An input signal of 0.125
volt is required to obtain a full output (2.5V) from the
preamplifier.

Use single-conductor shielded cable terminated in an RCA
phono plug for connecting auxiliary equipment. If hum is
experienced after making connections, connect a ground wire
between the chassis of the auxiliary unit and the GND terminal
of the CAM.

-0—-Q--'-

Unbalanced low or high impedance microphones

Figure 1 — Connecting microphone cables

Printed in USA 54-5617-09 9907

TECHNICAL SPECIFICATIONS

Rated output

Output impedance

Frequency response

Hum & Noise

Distortion

Equivalent input noise

Inputs

Gain

Lo~Z MIC!300 uV

Hi-ZMlCi3mV

AVXj30mV

Semiconductors

, 2.5V Hi-Z output; 125 mV Hi-Z MIC output: 12.5 mV Lo-Z MIC output

Lo-Z MIC 25-600 ohms, balanced or unbalanced; Hi-Z MIC 20,000 ohms, (or
higher) unbalanced; Hi-Z AUX output 50,000 ohms (or higher) unbalanced

Flat + 2 dB, 20-20,000 Hz

MIC 70 dB below rated output; AUX 80‘dB below rated output: MASTER 90 dB

below rated output

Less than I % at rated output

-l23dB/V

4 balanced or unbalanced Lo-Z MIC or HI-Z unbalanced MIC. ! AUX

Lo-Z MIC output Hi-Z MIC output Hi-Z output

+10 dB/lmV

-10 dB/lmV

-30 dB/lmV

+30 dB/IOmV

+ 10 dB/IOmV

-10 dB/TOmV

+66 dB/600mV

+46 dB;600mV

+26 dB/600mV

All silicon; 16 transistors, 2 diodes

Controls

Input/output connections

Power consumption

Dimensions

Weight

MODEL CAM

IIRIES

laov-i
so HZ

IT

28

.02 A VDC

aND

4 MIC volumes. 1 AUX volume, I MASTER volume, 1 POWER switch, 4 mic

input impedance selectors. I mic output impedance selector

Microphone; professional 3-pin audio connectors (male); Aux/Hi-Z : standard
phono jack

120VAC, 60 Hz, .02A; 24-28VDC, .OlA

ll%" W X 2K" H X 7%" D (28.9 x 7.3 x 19.7 cm)

4 lbs, (1.8 kg)

MICROPHONE IMPEDANCE SELECTORS

_______________

I -

__________

HIGH LEVEL

AUXILIARY POWER

INPUT

OUTPUT

MIC

LEVEL OUTPUT

Figure 2 — CAM, rear chassis

LO-Z OR HI-2

T

MIC INPUTS

C74-2355-OI

2