Bogen M120 Operating Manual

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BOGEN

MODEL M120

120 WATT PUBLIC ADDRESS AMPLIFIER

BOGE.\' DI VISION
PM 301500
Mums, x J mu

LEARSIEGLER. INCI/ @

INSTAllATION AND OPERATING MANUAL

READ THOROUGHLY BEFORE OPERATING EQUIPMENT

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INTRODUCTION

The Bogen model M120 is a general purpose 120 watt
public address amplifier. Seven inputs are provided; three
for microphones, two for magnetic phono or tape, and two
auxiliary inputs for ceramic phone or other high level sound
sources.

Separate volume controls are provided for the four input
channel§,and a master volume control to adjust the over-all
gain. arate bass and treble controls are provided for
adjusting the tonal balance.

TECHNICAL SPECIFICATIONS

POWER OUTPUT: 120 watts at less than 37. distortion;
I90 watts peak
FREQUENCY RESPONSE: 20 to 20,000 Hz 11 db
POWER RESPONSE: :3 db, 50 to 20,000 Hz at 120
watts less than 5% distortion.
HUM AND NOISE:
Mic Input: '65 db below rated power
AUX Input: 80 db below rated power
MAG Input: 65 db below rated power
GAIN:
MIC Input: 128 db
AUX Input: 102 db
MAG Input: 121 db

SENSITIVITY:
MIC Input: 9 millivolts
AUX Input: 0.4 volts
MAG Input: 24 millivolts
INPUTS

3 MIC high impedance (Convertible to low im-
pedance with plug-in transformer)

2 MAG phone (or tape head)

2 AUX (high level, high impedance)

OUTPUTS
8 and 16 ohm speakers
25 volt (5.2 ohm) balanced
70 volt (41 ohrII) balanced (from quick discon-
nect sockets)
TONE CONTROL ACTION
TREELE: -14/z db to +12 db at 10 kHz
BASS: -9% db to +15 db at 50 Hz
CONTROLS:
MIC 1 Volume, INPUT 2 Volume, INPUT 3 Volume
AUX l AUX 2 Volume (fader type)
MIC l Selector (hi3: or low impedance)
INPUT 2 Selector (high impedance, low impedance
or mag-tape)
INPUT 3 Selector (high impedance, low impedance
or mag-tape)
MASTER Volume, BASS, TREBLE, POWER switch
TUBES AND RECTIFIERS:
Four 8417, one 7247, two 6EU7, three silicon
rectifiers
POWER CONSUMPTION: 320 watts
SHIPPING WEIGHT: 36 lbs.

ACCESSORIES

PLUG-IN TRANSFORMERS

Plug-in transformers permit this amplifier to be used
with low impedance as well as with high impedance micro-
phones. Bogen transformer Model 'IMSO is used for 50 ohm
input, Model TM200 for 150 to 250 ohms, and Model TMSOO
for 500 to 600 ohms.

MODEL SR2 AND SR4 REMOTE CONTROLLER

The Remote Controller permits the user to control the
gazn of the MIC 1, INPUT 2 and INPUT 3 inputs from dis-
tances up to 2,000 feet from amplifier without sacrificing
power or signal quality. It also allows the user to mix and
fade the three signal inputs.

LK-6 CONTROL GUARD LOCKING PLATE

Bogen Model LK-6 control guard locking plate is
designed to prevent unauthorized tampering with the con~
trols of amplifier. It comes complete with two sets of
keys. The key cannot be removed when the lock is in
open position.

MODEL LPC-4 PHONO PLAYER TOP
Model LPG-4 is a complete four-speed phono player

UNPACKING

Inspect shipping container and unit for indications
of improper handling. The unit was carefully checked before
leaving factory. If unit has been damaged, make an immediate
claim to dealer or distributor from whom it was purchased.
If unit was shipped to you. notify transportation company
without delay and place your claim.

CONNECTIONS BETWEEN COMPONENTS

Use single conductor, low-capacity shielded audio wire
for connecting the record player, tape recorder, and other
components (except speakers) to amplifier. Keep leads under
35 feet in length.

Speakers may be connected with standard fleXible line
card (zip cord), and up to 100 feet of cable may be used
without appreciable loss.

Make certain that all audio cables are kept away from

~2-

designed to be mounted directly on top of the amplifier.
The unit comes complete with all necessary hardware. It
can easily be installed and connected to the amplifier with
only a screwdriver. It includes a vibration-isolated turntable
and tone arm housing a dual-stylus turn-over cartridge.

MSK-I MONITOR SPEAKER

The MSK-I is an optional Monitor Speaker and Volume
Control Accessory. The MSK-l enables the operator to
monitor the sount output level at the amplifier in installations
with remotely located speakers or serves as an added con-
venience in any installation.

MODEL WMT-I LINE MATCHING TRANSFORMER

The WMT-l may be used as an input transformer to
distribute music from a 500/600 ohm leased telephone line.
The accessory also functions as an output transformer for
feeding program material for transmission over a 500/600
ohm telephone line. Line input or output connections are
made conveniently to a three-screw terminal stripr Con-
nection to the amplifier is provided by a cable terminated
in a phone plug.

INSTALLATION

speaker cables. power cables, and power transformers, and
that speaker cables are kept away from power cables.

POWER AND GROUNDING

The amplifier is furnished with an AC line cord tenni-
nated in a threeprong plug. Plug the line cord into a three-
wire grounded outlet providing a nominal lZO-volt, 50-60
cycle power source. This will ground the amplifier as well
as supply power to it.

It is advisable to ground the amplifier. Therefore, if a
three-wire outlet is not available, an adapter such as Leviton
No. 5017 should be used to convert a standard two-wire out-
let for use with three-wire plugs. The adapter is provided
with a grounding pigtail which should be connected to the
screw holding the wall plate to the receptacle.