M-Class Amplifier M300, M450, & M600 Models Installation and Use Manual © 2001 Bogen Communications, Inc. All rights reserved.
Notice IMPORTANT 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 WARNING: To Reduce The Risk of Fire Or Electric Shock, Do Not Expose This Apparatus To Rain Or Moisture. Always follow these basic safety precautions when installing and using the unit: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. Read these instructions. Keep these instructions. Heed all warnings.
Contents Page INTRODUCTION ..................................................................................................1 Package Contents................................................................................................................1 PANEL DESCRIPTIONS ....................................................................................2-3 M-Class Front Panel............................................................................................................
Introduction Bogen's M-Class amplifiers deliver on what professional sound installers need most: Flexibility, Power, and Reliability. Flexibility The M-Class allows for the installation of up to 2 input modules, accepting inputs from microphones, telephone systems, stereo sources, mono sources, or daisy-chaining of amplifiers. Each M-Class model comes standard with a single, professional-quality, stereo, high-impedance balanced input module.
Panel Descriptions M-Class Front Panel 1. Status Indicators The Status LED is a multi-purpose indicator that lights in three colors to show status. One for each channel. • • • Green - Amplifier is on and operating normally. Amber - Amplifier is in low-power consumption Sleep Mode. Red - Amplifier has protected itself due to a fault condition. 2. Signal Indicators Illuminates green when signal is present at the input. One for each channel. 3.
Panel Descriptions M-Class Rear Panel 1. Low-Impedance Outputs Accepts up to #10 spade lugs for low-impedance speaker connections. 2. Channel Balance Only active in Dual Mono mode. Allows one channel’s volume to be adjusted relative to the other channel. 3/4. Effects Loop In/Out The effects loop connectors provide an insertion point for outboard signal processing equipment when the M-Class is operating in either 70V Mono or Dual Mono mode, where inputs provide a 2:1 mixer function. 5/6.
Installation Installation Components 1. Rack Ears Prior to installing the amplifier, you will need to attach the installation rack ears if you intend to install the amplifier in a rack and complete the setup process. Remove the 6 front most cover screws on each side panel of the amplifier and attach rack ears as shown. 2. Dust Filter Insert the dust filter into the fan grille before attaching the fan grille to the amplifier.
Installation Ventilation The M-Class was designed to be placed on a table or rack-mounted.When rack mounted, the amplifiers can be stacked one on top of the other for maximum use of the rack. An open air space of at least 4" must be provided at the front air intakes of the amplifier, and the rear exhaust must have at least a 4" gap from any obstructions to ensure adequate cooling. This applies to both rackand table-mounted amplifiers.
Installation Module Installation Installation Two input module bays are available to accept various Bogen input modules thereby allowing users to customize the amplifier to suit the needs of the installation. Read the instructions included with the module and make the desired jumper setting changes before installing the module. The sleep switch should be set to the desired position prior to installation of the right module since it will be covered by the module (see Operation, Sleep Mode Defeat).
Connections Speakers Low-Impedance Speaker Connections When the amplifier is set to either the stereo mode or the Dual Mono mode (see Operation section), low-impedance speakers can be connected to either the "A" or "B" speaker output terminals. The amplifier is designed to work into speaker load impedances as low as 3.2 ohms. The speaker terminals can accept up to a #10 spade lug and have integral clamping plates which make wiring easier.
Operation Controls & Connectors Level Controls The front-mounted level controls act differently depending on the mode of operation. In the stereo mode, each level control determines the volume of the corresponding amplifier channel as in a typical amplifier. In the 70V Mono and Dual Mono modes, the controls have a different function and determine the mix of the signal levels from the different input modules (input modules can be assigned to either the "A" or "B" channel by the jumpers on the module).
Operation Effects Loop The effects loop connectors act as an insertion point for outboard signal processing equipment when the M-Class is operating in either the 70V Mono or Dual Mono modes. In these modes, the inputs and front panel controls form a 2:1 mixer. Connect the Effects Loop Out to the input of the external signal processing equipment. Connect the Effects Loop In to the output of the external signal processing equipment.
Operation 70V Mono Mode Placing the 3-position switch to its right most position puts the amplifier in the 70V Mono mode of operation. The amplifier supplies a single channel of amplification in this mode (see 70V Mono Mode Block Diagram). This mode also mixes the signals from each input module into a mono program. Input signals of modules that are assigned to the "A" bus are controlled by the "A" level control on the front of the unit and likewise for modules whose outputs are assigned to the "B" bus.
Operation Modules Standard Input Module The M-Class is shipped with one input module pre-installed.The module provides 2 high-impedance, balanced, lownoise inputs, but can be replaced by other modules if desired. The input’s connectors, labeled A & B, correspond to the similarly marked rear speaker connections and front panel controls. The module’s inputs are permanently assigned to their respectively-labeled audio buses.
Applications Application Examples Application 1: Simple 1-Zone, 70V Mono telephone paging system with background music Background music plays through the system when no page is being made. During a telephone page, the background music mutes to a predetermined level and the telephone page is heard.When the page is complete, the background music fades back to its previous level.
Applications Application 3: Global music/message buffered and distributed to multiple amps with local override input for each amplifier Similar to the paging situation found at airport departure gates, global music/messages play when no local page is present. During local page (from departure gate microphone), music/message mutes to predetermined level and page is heard only in local area. When local page is complete, global music/message fades back to previous level.
Troubleshooting PROBLEM CONDITION CAUSE Status LED is off. • Amplifier not plugged in. • AC outlet dead. • Power switch off. • Breaker (power switch) tripped. - Turn off, then turn back on. Status LED is green. Signal LED is off. • Level controls turned down. • No signal from source. • Input module jumpers in wrong bus configuration (if available). Status LED is green. Signal LED is green. Clip/Limit LED is off. • 70V mono connections on amplifier incorrect. • Poor/broken speaker wiring.
Specifications Technical Specifications Power Output 70V Mono 4-ohm 8-ohm M600 M450 M300 900W @ 5.5 ohms 450W per channel* 300W per channel* 600W @ 8 ohms 300W per channel* 200W per channel* Input Sensitivity At Backplane Connector or using 1.161V for 600W @ 4 ohms Standard Input Module (incl.) (Module has Gain of 1) 1.010V for 450W @ 4 ohms 0.840V for 300W @ 4 ohms S/N Ratio (20K BW) 109 dB ref. 8 ohms, F.P. 106 dB ref. 8 ohms, F.P. 103 dB ref. 8 ohms, F.P.
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