The
Bogen HTA125A and HTA250A Series Power Amplifiers
are high performance units. MOSFET technology delivers distor-
tion-free power into reactive loads, such as high-performance
loudspeakers or transformers.
The HTA125A supplies 125 watts (HTA250A supplies 250 watts)
continuous RMS output at less than 0.5% total harmonic distor-
tion, with a frequency response of ±1 dB from 20 Hz to 20 kHz.
An input signal of only 500mV is required for full rated output
(150mV for low-impedance balanced input with Model TL600 ac-
cessory transformer). Input impedances are high-impedance un-
balanced and low-impedance balanced (with TL600 accessory
transformer). Outputs include 4-ohm, 8-ohm, 25V (combined with
4-ohm output in HTA125A), 25VCT, and 70V. Line-bridging may
be achieved with Bogenʼs TL100 accessory (transformer).
The amplifiers are thermally protected to prevent damage due to ex-
cessive temperatures. The unique self-protecting output stage pre-
vents thermal runaway which is often encountered in conventional
amplifiers.
Electric shutdown circuitry is activated if an overload or short oc-
curs and a front panel OVERLOAD SHUTDOWN LED illuminates.
Once the cause has been rectified, the unit automatically resets.
The power ON/OFF switch, located on the front panel, illuminates
when power is ON. The rear panel contains an Input Level control,
Input and Output connections, AC Line Fuse, and an Auxiliary Re-
ceptacle. A Low-Cut Filter switch is located internally on the printed
circuit board.
Rack Mounted Installation
The amplifier is designed for installation in a standard 19” equip-
ment rack. Position the unit in the rack and secure with screws
through the amplifier front panel.
NOTE:
Before placing the amplifier in a rack, install any accessory
transformers required.
Ventilation
The amplifier generates heat during operation. It must be prop-
erly ventilated to prevent excessive temperature rise. If other heat-
producing equipment, or several amplifiers have been installed in
an enclosed rack or cabinet, you must ensure that there is space
above and below the amplifier(s) to allow for passive cooling. It is
recommended that the amplifier be installed on the bottom of a
rack or above any equipment that does not produce heat.
Power and Grounding
The AC line cord has a 3-prong plug which should be plugged into
a 3-wire grounded, 120V AC, and 60 Hz outlet. It is important to
ground the amplifier.
Auxiliary Power Receptable
Caution:
The front panel ON/OFF switch does not control the
auxiliary receptacle.
The auxiliary power receptacle on the rear panel is a 3-wire
grounded outlet and may be used to supply power to accessory
equipment in the sound system. Ensure that the accessory equip-
ment does not require more than 300 watts. Equipment connected
to the auxiliary receptacle with a 3-prong line cord will be grounded,
providing the amplifier line cord has been properly grounded.
Description
Installation
