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
AUDIO
AUDIO
OUTPUT
OUTPUT
AM/FM TUNER
AM/FM TUNER
MUSIC SOURCE
MUSIC SOURCE
600Ω BALANCED
600Ω BALANCED
SPEAKER LEVEL
SPEAKER LEVEL
OUTPUT
OUTPUT
TO TELEPHONE
TO TELEPHONE
MOH INPUT
MOH INPUT
AM/FM RECEIVER
AM/FM RECEIVER
OUTPUT
OUTPUT
ALTERNATE
ALTERNATE
CONNECTION
CONNECTION
TO GA2
TO GA2
220 Ω
TYPICAL
TO
ADDITIONAL
JACKS
TYPICAL - 200 / 600-OHM HEADPHONES
SELF-AMPLIFIED
SPEAKER
BOGEN WMT1A
TO 600 Ω
TELEPHONE
PAGING
INTERFACE
SELF-AMPLIFIED HORN
POWER
SUPPLY
TO ADDITIONAL
SELF-AMPLIFIED
SPEAKERS
8Ω
8Ω / 1.5W
1.5W
SPEAKER LEVEL
SPEAKER LEVEL
OUTPUT
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 Ω
TYPICAL
TO
ADDITIONAL
JACKS
TYPICAL - 200 / 600-OHM HEADPHONES
SELF-AMPLIFIED
SELF-AMPLIFIED
SPEAKER
SPEAKER
BOGEN WMT1A
BOGEN WMT1A
TO 60
TO 600 Ω
TELEPHONE
TELEPHONE
PAGING
PAGING
INTERFACE
INTERFACE
SELF-AMPLIFIED HORN
SELF-AMPLIFIED HORN
POWER
POWER
SUPPLY
SUPPLY
TO ADDITIONAL
TO ADDITIONAL
SELF-AMPLIFIED
SELF-AMPLIFIED
SPEAKERS
SPEAKERS
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 Ω
220 Ω
TYPICAL
TYPICAL
TO
TO
ADDITIONAL
ADDITIONAL
JACKS
JACKS
TYPICAL - 200 / 600-OHM HEADPHONES
TYPICAL - 200 / 600-OHM HEADPHONES
SELF-AMPLIFIED
SPEAKER
BOGEN WMT1A
TO 600 Ω
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
