Bogen CAM User Manual

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
address 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, 60Hzor 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-1 In-WfcU 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.
INPUT CONNECTIONS
HIGH IMPEDANCE MICROPHONES
High-impedance microphones (approximately 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, high-
impedance 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. r
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.
Unbalanced low or high impedance microphones
Balanced low impedance microphones
Figure 1 — Connecting microphone cables
Printed in USA 54-5617-09 9907