Bogen GA2 Guide

© 2011 Bogen Communications, Inc.
All rights reserved.
Specifications subject to change without notice.
54-5740-03B 1110
1.5W Utility Amplifier
GA2 Model
Installation and Use Manual

CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
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.
WARNING: To reduce the risk of Fire or Electric Shock, Do Not Expose this apparatus
to rain or moisture.
Apparatus shall not be exposed to dripping or splashing and no objects filled with liquids,
such as vases shall be placed on the apparatus.
WARNING: Only connect unit to AC mains outlet providing protective earthing connection.
NOTE: Mains plug is used as disconnect device from the mains and shall remain readily
accessible and operable.
CAUTION: These servicing instructions are for use by qualified service personnel only. To reduce the
risk of electric shock, do not perform any servicing other than that contained in the operating
instructions unless you are qualified to do so.
CAUTION: DO NOT INSTALL OR PLACE THIS UNIT IN A BOOKCASE, BUILT-IN CABINET, OR IN
ANOTHER CONFINED SPACE. ENSURE THE UNIT IS WELL VENTILATED. TO PREVENT THE RISK
OF SHOCK OR FIRE HAZARD DUE TO OVERHEATING, ENSURE THAT CURTAINS AND ANY OTHER
MATERIALS DO NOT OBSTRUCT THE VENTILATION VENTS.
Always follow these basic safety precautions when installing and using the unit:
IMPORTANT SAFETY INSTRUCTIONS
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean unit with dry cloth.
7. Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
8. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus
(including amplifiers) that produce heat.
9. Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two
blades with one wider than the other. A grounding-type plug has two blades and a third grounding
prong. The wide blade, or the third prong, are provided for your safety. If the provided plug does not
fit into your outlet, consult an electrician for replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles,
and the point where they exit from the apparatus.
11. Only use attachments/accessories specified by the manufacturer.
12. Unplug this apparatus during lightning storms or when not used for long periods of time.
13. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been
damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or
objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not
operate normally, or has been dropped.
CAUTION: TO PREVENT THE RISK OF ELECTRIC
SHOCK, DO NOT REMOVE ANY FRONT/BACK COVERS
OR PANELS. NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED PERSONNEL.
The exclamation point within an equilateral triangle is in-
tended to alert the user to the presence of important
operating and maintenance (servicing) instructions.
The lightning flash with arrowhead symbol, within an equi-
lateral triangle, is intended to alert the user to the presence
of uninsulated "dangerous voltage" within the product's en-
closure that may be of sufficient magnitude to constitute a
risk of electric shock to persons.

Bogen Model GA2 is a rugged and compact 1.5 watt amplifier designed to meet the requirements of continuous low-power audio appli-
cations. It is ideally suited for telephone line music-on-hold amplification. It can be used to drive monitor speakers, headphones, or as a
line amplifier. With accessory transformer WMT1A connected to the input, the GA2 will provide amplification for a 600-ohm telephone line.
The amplifier provides a high-level input with screwdriver-adjustable volume control, and both an 8-ohm and 600-ohm output. The
input is available at either a phone jack or screw terminals. Sensitivity for full output is 50 mV. Outputs are available via screw terminals.
The GA2 is listed to UL Standard 60065 for the U.S. and Canada.
Typical Applications
The GA2 can be used to interface the music-on-hold function
of various telephone systems to the output of an audio
source.
The GA2 can be used for telephone systems with provisions
for music-on-hold that require either 600-ohm or 8-ohm/1.5W
input to their MOH inputs.
When used as a line amplifier, the 600-ohm balanced, or
8-ohm output of the GA2 can be used to drive the input of
power amplifier(s) remotely located from the music source.
Figure 2 illustrates use of Model GA2 as a multiple head-
phone driver. With this arrangement, the amplifier can drive
up to 20 pairs of headphones.
CAUTION:
To prevent overdriving an amplified speaker system,
use the following setup procedure.
1) Set all of the zone amplified speaker volume controls to
the maximum “ON” position.
2) Adjust the GA2 output to a level slightly louder than is
normally required at the speaker.
3) Adjust the individual amplified speaker volume level
control to the desired volume level.
Technical Specifications
Power Output: 1.5 watts RMS
Frequency Response: 200 Hz to 15 kHz +0 dB, -2.5 dB
Total Harmonic Distortion: 2% @ 1.5W, 0.25% @ 1W
Output Level: +6 dBm (1.5V) across balanced 600 ohms
Sensitivity: 50 mV
Input Impedance: 100 kilohms
Hum and Noise: -72 dB below rated output
Output Impedance: 8 ohms; 600 ohms balanced
Control: Volume, screwdriver-adjustable
Terminations:
Output — terminal strip
Input — RCA-type phono jack or terminal strip
Power Consumption: 4W, 120V ~, 60 Hz
Dimensions: 5-1/2" W x 4-1/8" H x 2-1/4" D
Product Weight: 2 lb.
GA2 1.5W Utility Amplifier
AUDIOAUDIO
OUTPUTOUTPUT
AM/FM TUNERAM/FM TUNER
MUSIC SOURCEMUSIC SOURCE
600Ω BALANCED600Ω BALANCED
SPEAKER LEVELSPEAKER LEVEL
OUTPUTOUTPUT
TO TELEPHONETO TELEPHONE
MOH INPUTMOH INPUT
AM/FM RECEIVERAM/FM RECEIVER
OUTPUTOUTPUT
ALTERNATEALTERNATE
CONNECTIONCONNECTION
TO GA2TO GA2
220 Ω
TYPICAL
TO
ADDITIONAL
JACKS
TYPICAL - 200 / 600-OHM HEADPHONES
SELF-AMPLIFIED
SPEAKER
BOGEN WMT1A
TO 600Ω
TELEPHONE
PAGING
INTERFACE
SELF-AMPLIFIED HORN
POWER
SUPPLY
TO ADDITIONAL
SELF-AMPLIFIED
SPEAKERS
8Ω8Ω / 1.5W1.5W
SPEAKER LEVELSPEAKER LEVEL
OUTPUTOUTPUT
AUDIO
OUTPUT
AM/FM TUNER
MUSIC SOURCE
600Ω BALANCED
SPEAKER LEVEL
OUTPUT
TO TELEPHONE
MOH INPUT
AM/FM RECEIVER
OUTPUT
ALTERNATE
CONNECTION
TO GA2
220 Ω
TYPICAL
TO
ADDITIONAL
JACKS
TYPICAL - 200 / 600-OHM HEADPHONES
SELF-AMPLIFIEDSELF-AMPLIFIED
SPEAKERSPEAKER
BOGEN WMT1ABOGEN WMT1A
TO 60TO 600 Ω
TELEPHONE
TELEPHONE
PAGINGPAGING
INTERFACEINTERFACE
SELF-AMPLIFIED HORNSELF-AMPLIFIED HORN
POWERPOWER
SUPPLYSUPPLY
TO ADDITIONALTO ADDITIONAL
SELF-AMPLIFIEDSELF-AMPLIFIED
SPEAKERSSPEAKERS
8Ω / 1.5W
SPEAKER LEVEL
OUTPUT
AUDIO
OUTPUT
AM/FM TUNER
MUSIC SOURCE
600Ω BALANCED
SPEAKER LEVEL
OUTPUT
TO TELEPHONE
MOH INPUT
AM/FM RECEIVER
OUTPUT
ALTERNATE
CONNECTION
TO GA2
220 Ω220 Ω
TYPICALTYPICAL
TOTO
ADDITIONALADDITIONAL
JACKSJACKS
TYPICAL - 200 / 600-OHM HEADPHONESTYPICAL - 200 / 600-OHM HEADPHONES
SELF-AMPLIFIED
SPEAKER
BOGEN WMT1A
TO 600Ω
TELEPHONE
PAGING
INTERFACE
SELF-AMPLIFIED HORN
POWER
SUPPLY
TO ADDITIONAL
SELF-AMPLIFIED
SPEAKERS
8Ω / 1.5W
SPEAKER LEVEL
OUTPUT
Figure 1: Connection Diagram for Tuner or Receiver to Music-On-Hold
Figure 3:
Typical Self-Amplified
Speaker System
Figure 2: Typical 200/600-Ohm Headphones

50 Spring Street, Ramsey, New Jersey 07446, U.S.A.
Tel. [phone] • Fax: [phone]
www.bogen.com
The Bogen GA2 Utility Amplifier is warranted to be free from defects in material and workmanship for two (2) years from the date of sale to the original
purchaser. Any part of the product covered by this warranty that, with normal installation and use, becomes defective (as confirmed by Bogen upon inspection)
during the applicable warranty period, will be repaired or replaced by Bogen, at Bogen’s option, provided the product is shipped insured and prepaid to:
Bogen Factory Service Department, 50 Spring Street, Ramsey, NJ 07446, USA. Repaired or replacement product will be returned to you freight prepaid.
This warranty does not extend to any of our products that have been subjected to abuse, misuse, improper storage, neglect, accident, improper installation
or have been modified or repaired or altered in any manner whatsoever, or where the serial number or date code has been removed or defaced.
THE FOREGOING LIMITED WARRANTY IS BOGEN’S SOLE AND EXCLUSIVE WARRANTY AND THE PURCHASER’S SOLE AND EXCLUSIVE
REMEDY. BOGEN MAKES NO OTHER WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, AND ALL IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED AND EXCLUDED TO THE MAXIMUM EXTENT
ALLOWABLE BY LAW. Bogen's liability arising out of the manufacture, sale or supplying of products or their use or disposition, whether based upon
warranty, contract, tort or otherwise, shall be limited to the price of the product. IN NO EVENT SHALL BOGEN BE LIABLE FOR SPECIAL, INCIDENTAL
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, LOSS OF PROFITS, LOSS OF DATA OR LOSS OF USE DAMAGES) ARIS-
ING OUT OF THE MANUFACTURE, SALE OR SUPPLYING OF PRODUCTS, EVEN IF BOGEN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES OR LOSSES. Some States do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion
may not apply to you. This warranty gives you specific legal rights, and you may also have other rights which vary from State to State.
Products that are out of warranty will also be repaired by the Bogen Factory Service Department – same address as above or call 201-934-8500. The parts
and labor involved in these repairs are warranted for 90 days when repaired by the Bogen Factory Service Department. All shipping charges in addition to
parts and labor charges will be at the owner's expense. All returns require a Return Authorization number. For most efficient warranty or repair service,
please include a description of the failure.
12/2008
Limited Warranty; Exclusion of Certain Damages