Bogen CAM2 User Manual

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CAM2 Mixer/Pre-Amplifier

Installation and Use Manual

© 2001 Bogen Communications, Inc.

All rights reserved. Specifications subject to change. 54-2039-01R2Printed in Korea. 0112

Notice

Every effort was made to ensure that the information in this guide was complete and accurate at the time of printing. However, information is subject to change.

Important Safety Information

Always follow these basic safety precautions when installing and using the unit:

1. Read all instructions.

2.Follow all warnings and instructions marked on the product.

3.DO NOT place the product in a separate enclosure or cabinet, unless proper ventilation is provided.

4.Never spill liquid on the product.

5.Repair or service must be performed by a factory authorized repair facility.

6.DO NOT staple or otherwise attach the AC power supply cord to building surfaces.

7.DO NOT use the product near water or in a wet or damp place (such as a wet basement).

8.DO NOT use extension cords. The product must be installed within 6 feet of a grounded outlet receptacle.

9.Use caution when installing or modifying paging or control lines.

Applications Assistance

Our Applications Engineering Department is available to assist you from 8:30 A.M. to 6:00 P.M. and on call until 8:00 P.M., Eastern Standard / Daylight Time, Monday through Friday. Call 1- 800-999-2809,Option 2.

Domestic and International Listings

The CAM2 is a UL, CSA listed product.

Contents

 

Page

INTRODUCTION & INSTALLATION ..........................................................................................

3

Introduction ..........................................................................................................................................................

3

Installation..............................................................................................................................................................

3

PANEL DESCRIPTIONS ..................................................................................................................

4

Front Panel ............................................................................................................................................................

4

Rear Panel ..............................................................................................................................................................

4

INPUT CONNECTIONS ..............................................................................................................

5-6

Microphone Inputs ..............................................................................................................................................

5

Phantom Power ....................................................................................................................................................

5

Microphone Cable Wiring..................................................................................................................................

6

AUX IN ..................................................................................................................................................................

6

OUTPUT CONNECTIONS..........................................................................................................

7-8

BAL/OUT to Balanced Input of Other Equipment......................................................................................

7

BAL/OUT to Microphone Input of Other Equipment................................................................................

7

LINE OUT..............................................................................................................................................................

8

BRIDGING MIXERS..........................................................................................................................

9

Bridging Connections ..........................................................................................................................................

9

OPERATION....................................................................................................................................

10

Power ..................................................................................................................................................................

10

MIC Gain Control..............................................................................................................................................

10

AUX Gain Control............................................................................................................................................

10

Clip Indicator......................................................................................................................................................

10

Master Gain Control ........................................................................................................................................

10

Output Level Meter ..........................................................................................................................................

10

AUDIO SYSTEM LEVEL ................................................................................................................

11

Setting System Levels........................................................................................................................................

11

SPECIFICATIONS ..........................................................................................................................

12

LIMITED WARRANTY ..................................................................................................................

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Introduction & Installation

Introduction

The Bogen Model CAM2 is a mixer/pre-amplifierthat provides four MIC inputs and one AUX input while supplying both MIC and high level outputs. The CAM2 is particularlywell-suitedfor expanding the number of inputs of Bogen public address amplifiers.

The CAM2 accommodates low-impedancemicrophones and has an input for tuners or other high level sources. Outputs are provided forhigh-impedanceunbalanced andlow-impedancebalanced MIC inputs and line level inputs to a public address amplifier, tape deck or similar equipment. Units may be interconnected to provide a greater number of inputs.

The CAM2 operates from a 120V AC, 60Hz 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-wallmounting 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-prongplug that should be plugged into athree-wire,grounded 120V AC, 60Hz outlet. If athree-wireoutlet 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 themixer/pre-amplifierto 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-rolledsteel and finished in black enamel.

In-WallMounting

Bogen Model WMK1 is designed to mount the mixer/pre-amplifierflush in a wall. Depth of the mounted unit is3-1/2".

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Panel Descriptions

Front Panel

1. Input Over Voltage LEDs (Clipping LED) - LED will light when input is overdriven.

2.MIC Channel Gain Controls - Controls the gain levels of the MIC channels.

3.AUX Gain Control - Controls the gain level of the AUX input.

4.Output Meter - LED meter indicates peak output signal level.

5.Master Gain Control - Adjusts the overall output level.

6.Power Switch & Power Indicator - Power switch will illuminate when Power Switch is turned "ON".

Rear Panel

1. Power Connection - 120V AC, 60Hz, .043A.

2.Output XLR Connector - Provides a balanced output compatible with most professional audio equipment.

3.Output Level Switch - Switch changes the nominal signal level of the XLR output from +4dB to-50dB.

4.Line Output Connector (Line Out) - RCA jack provides output signal levels compatible with most amplifiers, recording equipment, and other audio equipment. Not affected by Output Level switch.

5.Bridging - The bridging jacks facilitate the connecting together of mixers to obtain additional inputs without using any of the CAM2 inputs.

6.Auxiliary Input (AUX In) - A dedicated unbalanced auxiliary input for tuner, tape deck, CD player, etc.

7.MIC Inputs - Balanced MIC level XLR inputs.

8.Phantom Power - The CAM2 provides power for electret condenser microphones.The Phantom ON/OFF switch controls the applications of DC voltage to each MIC input.

4

Input Connections

Microphone Inputs

Microphones are connected to the CAM2 using the MIC1 through MIC 4 connectors.The CAM2 uses male XLR type connectors for making connections to its inputs. Microphones typically accept female XLR connectors. Cables with male and female XLR connectors already attached are commonly available at retail stores or through Bogen. The figure below shows the connection of various microphones.

Phantom Power

Each MIC input has a PHANTOM switch associated with it.This

switch must be set correctly for the type of microphone being used with that MIC input. Microphones come in two basic types: Dynamic and Electret Condenser. When using Dynamic

microphones, set the PHANTOM switch for that microphone

input to OFF. When using an Electret Condenser microphone, set the PHANTOM switch to ON. Elecret Condenser microphones require a DC voltage to power their internal circuitry.When the PHANTOM switch is set to ON, the microphone input will supply a DC voltage back to the Electret Condenser microphone through the microphone cable (this is called providing Phantom Power to the microphone).

If the PHANTOM switch is set to ON when using a Dynamic microphone, you may hear a loud pop every time the microphones ON/OFF switch is changed. If you do hear this, then check that the PHANTOM switch for that microphone input is set properly.

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Input Connections

Microphone Cable Wiring

The CAM2 has female XLR connectors as its microphone inputs, these connectors have 3 pins and are designed to be connected to balanced, low-impedancemicrophones.These microphones require 3 connections and use a cable that has two insulated conductors and a shielding material that encases the conductors (the shield provides the third connection). The use of balanced microphones provides superior protection against the pickup of unwanted hum, noise, and interference. It allows long cables to be used to connect the microphones to the CAM2.

The figure below shows how to wire the Male and Female XLR connectors onto a 2-conductorwith shield cable to make custom microphone cables.

AUX IN

Certain music input sources, such as tape decks and CD players, send larger signal levels that microphone inputs are not suited to accept. Microphone inputs are very sensitive and if one

of these devices were connected to a microphone input, then the output from the CAM2 would be distorted and unusable.

Since it is common to have recorded music mixed together with live sound from microphones, the CAM2 provides a single AUX input for the connection of a tape deck, CD player, tuner or similar equipment.The AUX IN connection has the appropriate input sensitivity to accept signals from these types of equipment.The input uses an unbalanced RCA connector which is typical of the output from playback equipment. RCA patch cords are readily available for making connections to this input. However, this is a mono input so the output from a stereo source must be combined by a Y-adapterso that both halves of the stereo playback are heard.The AUX input is an unbalanced input.When using unbalanced inputs, it is a good idea to keep the length of the connecting cable to 10 feet or less.

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Output Connections

BAL/OUT to Balanced Input of Other Equipment

The CAM2 provides a balanced output signal from the male XLR connector labeled BAL/OUT. Many types of professional equipment, like power amplifiers, have balanced inputs that are compatible with this output.The figure below shows the connection to a balanced input that has screw terminals. Many balanced inputs use XLR connectors. For XLR inputs, a standard MIC cable can be used.The figure in the next section shows this type of cable.The balanced output provides the same type of protection from noise and interference that the balanced microphones have and requires 3 wires to make the connections. For the best results, use this output connector if running the CAM2 output over long distances. When using the BAL/OUT to feed amplification or recording equipment, set the OUTPUT LEVEL switch to the +4dB position. This position provides the larger output voltages (relative to the smaller microphone output signals) required by other equipment.

BAL/OUT to Microphone Input of Other Equipment

It is sometimes necessary to feed the CAM2 output to the microphone input of another piece of equipment. However, the signal level of the CAM2’s output must be at a voltage level compatible with microphone inputs. Microphone inputs require much smaller signal voltages than the inputs of other equipment.To accommodate this requirement, the CAM2 OUTPUT LEVEL switch can be set to the -50dBposition. In this position, the output level of the CAM2 will be reduced to one that is compatible with microphone inputs. The CAM2 BAL/OUT connector requires a female XLR connector and the microphone inputs of other equipment typically require a male XLR.Therefore, a female to male XLR cable must be used for this type of connection.The diagram below shows the wiring of this type of cable and also the correct OUTPUT LEVEL switch position for feeding microphone inputs.

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Output Connections

LINE OUT

Unbalanced inputs are also popular on many pieces of equipment that the CAM2 may feed. To make the connection as easy as possible, the CAM2 provides an unbalanced LINE OUT signal that is of the proper signal level to connect to most equipment.An RCA patch cord is used to make this connection and is commonly available at retail stores. Since this output is unbalanced, it is important to keep the length of the connecting cable relatively short. Less than 10 feet is recommended. The figure below shows the general way in which the LINE OUT of the CAM2 is connected to the unbalanced input of an amplifier.

8

Bridging Mixers

Bridging Connections

In certain applications, more than four microphones or a single AUX input is needed. In these cases a CAM2 can be connected to another CAM2 to increase the number of inputs available.The BRIDGING connectors are provided for this purpose.To combine two to four CAM2 units together, connect an RCA patch cord between either of the BRIDGING connectors on one unit to either of the BRIDGING connectors of the other unit.The 2 RCA Bridging connectors on the CAM2 are wired together in parallel to allow units to be easily “daisy chained” together. The Bridging connectors provide access to the internal mix bus of each CAM2. When bridged together, the output of any of the CAM2 units can be used as the output to other equipment because the same output signal is present on each unit’s output. However, master volume control for all of the mixers will be the MASTER control on the CAM2 whose output is being used. The MASTER control of all of the other units have no effect on system volume. See the section on operation for more information.

Note: Bridging more than four CAM2 units together may reduce the maximum system output signal level below what is necessary to drive amplifiers and recording equipment.

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