Bogen CAM2 - Manual (Page 12)

Operation
Power
This switch applies power to the unit.The Switch Actuator will light to indicate power "ON" when
connected to an AC power source.
MIC Gain Control
The four MIC volume controls are used to adjust the level of individual mic input channels. Rotate
these controls clockwise (to the higher numbers) to increase volume and counter-clockwise (to
the lower numbers) to reduce volume. Use these controls and the AUX control to mix the input
signals to the desired levels.
AUX Gain Control
Controls the AUX input volume and functions the same as the MIC volume controls.
Clip Indicator
Each input channel has a dedicated red clip-
ping indicator to the right of the channel’s
label. During normal operation, the CLIP
indicators for each input should remain unlit or light infrequently.
If the indicator is lighting frequently or constantly, it indicates that the input is being overdriven by too much input
signal level.The input of the CAM2 can only accept signals up to a certain level. Once the input signal becomes larg-
er than the handling capability of the input circuits, the circuitry will begin to distort the input signal. The distortion
will produce poor sound quality on that channel.This condition is called overdriving the input.The distortion of the
input signal cannot be corrected by turning down the input level control because the signal is being distorted before
the level control can affect it. All the level control can do, in this case, is adjust the level of the now distorted sig-
nal.To correct this situation, the level of the signal source must be reduced so that it is no longer overdriving the
input.Typically, microphones will not overdrive their inputs. However, other equipment that is connected to a MIC
input has a high likelihood of overdriving the input. Note that the -50 dB setting of the CAM2 BAL/OUT’s Output
Level switch was provided to avoid this very situation when a CAM2 BAL/OUT signal is connected to another MIC
input.The AUX input can also be overdriven, but the signal levels necessary to do this are much higher than those
of a MIC input. Normally using the outputs of CD players, tuners, and tape players will not cause this problem.
However, connection to the speaker outputs of boom boxes, stereo amplifiers, and other equipment designed to
drive speakers can overdrive the AUX input.
Master Gain Control
This control regulates the overall output level of the CAM2. After setting the MIC and AUX con-
trols to provide the desired mix of input signal sources, adjust the MASTER control for the desired
overall volume level throughout the audio system. The MASTER gain control affects both the
BAL/OUT and LINE OUT signals.
Output Level Meter
The output level meter is provided as a tool for getting the optimum performance from the
CAM2. Using the individual level controls and the master, adjust the levels as desired but below
the level that caused the red +3 output level meter indicator to light (it can light infrequently on
short peaks in the sound). If the output signal is very low, as in quiet passages in music, the out-
put level meter may not light at all. It was designed to assist in the operation of the CAM2 as the
output signal levels approach critical maximum output level. If the red indicator is flashing fre-
quently or constantly, it means that the output signal from the CAM2 is becoming distorted and could be causing
poor sound quality.Turn down the MASTER control, or the individual control of a particularly loud input, to bring
the meter out of the red range. See the section on setting up system gains for further tips on levels.
Introduction & Installation
Introduction
The Bogen Model CAM2 is a mixer/pre-amplifier that provides four MIC inputs and one AUX input while supply-
ing both MIC and high level outputs. The CAM2 is particularly well-suited for expanding the number of inputs of
Bogen public address amplifiers.
The CAM2 accommodates low-impedance microphones and has an input for tuners or other high level sources.
Outputs are provided for high-impedance unbalanced and low-impedance balanced MIC inputs and line level inputs
to a public address amplifier, tape deck or similar equipment. Units may be interconnected to provide a greater num-
ber of inputs.
The CAM2 operates from a 120V AC, 60 Hz source. It may be mounted in a standard 19" equipment rack using a
Bogen Model RPK35B rack mounting kit or in a wall with a Bogen Model WMK1 in-wall mounting kit.
Caution: To reduce the risk of fire or electric shock, do not expose this unit to rain or excessive moisture.
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 & Grounding
The AC line cord has a three-prong plug that should be plugged into a three-wire, grounded 120V AC, 60Hz out-
let. If a three-wire outlet is not available, then use an adapter and secure the pigtail lead to the grounded wall plate
mounting screw. It is important to ground the unit. If the wall plate screw is not grounded, connect the wire from
the GND terminal of the mixer/pre-amplifier to a suitable earth ground.
Installation
Rack Mounting
Bogen Model RPK35B Rack Panel Kit is designed to mount the CAM2 in a standard 19" sound equipment rack. The
panel is fabricated from cold-rolled steel and finished in black enamel.
In-Wall Mounting
Bogen Model WMK1 is designed to mount the mixer/pre-amplifier flush in a wall. Depth of the mounted unit is
3
1 /
2
".
3 10