Altec 1224ax xover service manual

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1224A / 1224AX ELECTRONIC
ALT-EC CROSSOVER BIAMPLIFIER

SOUND PRODUCTS DIVISION

Aursq 1224A

AMDUIIEI
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DESCRIPTION

The Altec 1224A and 1224AX are rugged elec~
tronic crossover biamplifiers designed to be
installed in the cabinets of permanently
installed, portable sound reinforcement and
reproduction speaker systems. The 1224A and
1224AX are identical in all respects except for
line voltage requirements. The 1224A operates
on 120V ac, 50/60 Hz; the 1224AX, on 240V ac,
50/60 HZ. Either model, however, can be field
converted to operate on 240V or 120V ac.

The biamplifier includes electronic crossover
circuitry and separate low-frequency and high.
frequency amplifiers in a single, compact pack-
age. The electronic crossover circuit divides the
input signal into separate bass and treble chan-
nels before amplification. Electrically separate
amplifiers drive the low-frequency speaker and

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high-frequency driver. Crossover frequencies of
500 Hz, 800 Hz and 1500 Hz with 12 dB/octave
slope rates are selected by a slide switch located
on the back of the unit.

Input connection is made via an XL-type, 3-pin,
female connector. A parallel XL-3 pin male con-
nector is provided for conveniently connecting
two or more biamplifiers to a single driving
source. Output connections are made through
four push-type connectors on the units side.

Two gain controls are provided. A full gain control balances the output of the biam-
plifier with another biamplifier or conventional
amplifier driven from the same source, and a
high-frequency gain control provides high-
frequency to low-frequency spectral balance.