Ab international 644 a brochure

This is the 2 pages manual for ab international 644 a brochure.
Read or download the pdf for free. If you want to contribute, please mail your pdfs to info@audioservicemanuals.com.

Page: 1 / 2
left right
ab international 644 a brochure

Extracted text from ab international 644 a brochure (Ocr-read)

Page 1








advanced Technology Design Series 1V from
AB International is a modular system of high
performance power amplifiers and electronic sig-
nal processing that may be precisely tailored to
the specific requirements of professional loud-
speaker components. The experience gained from
building three generations of signal-processing
power amplifiers brings new features and new
standards of performance to ATD IV.

The AB International ATD Series 644A is a four
channel power amplifier. This compact (three
rack unit) instrument features individual channel
Dip switch level controls and signal/clip indica-
tors, XLR inputs (balanced), and a ground lift
switch, The 644A delivers 270 Watts per channel
8 Ohm, 425 Watts per channel into 4 Ohm, and
290 Watts into 2 Ohm.

The 644A employs only ZOdB of negative feed-
back to reduce forward tran sfer distortion compo
nents to minimum levels. Vl energy limiters are
incorporated for short- circuit protection and a
thermal sensor prevents an over-temperature conr

Other features include convection cooling with):
massive heatsink array and a temperature activatec
DC fan for extreme load conditions, " Soft Clip'
speaker protection circuitry, selectable input sensi
tivity, ground lift switch and a fully modular con
struction for service accessibility.

The AB International Model 644A features de
layed-ON , instant-OFF muting control circuit al
lows supply voltages to stabilize before loudspeak
ers are connected. Speaker connections are in
stantl y removed , should there be an interruption 0
AC power.

For users desiring specific non-smndard feature
and/or signal processing , a wide variety of option
are available, including high pass frequencies ,cross
over frequencies and filter topology and HF powe
response equalization , contact AB Internationa
for details.

The 644A operates from 10()»240V 50-60Hz AC
mains and measures 5 1/4 " high (three rack unit)
19" wide and 12.0" deep.