Altec 1753a manual

Page 1

ALTEC

LANSING?"

1 753A
28 Band

KEY SPECIFICATIONS

Tyne:

Frequency Response:
(reference 1 kHz)

THD:
(0 dBm output, unity gain)

IMD (SMPTE):
(0 dBm output, unity gain)

Noise:
(unity gain, unweighted)

Dynamic Range:
Load Impedance:
Operating Gain:

Available Gain:

Active filter set with 28
constanHl minimum phase
shift band-pass filters at ISO
preferred 1/3 octave center
frequencies.

20 Hz to 20 kHz, + OH dB.

<0.03%.

<0.03%.

>-78 dBm.

>110 dB.

600 ohms or higher.
MB.

20 dB.

1/3 Octave Equalizer

DESCRIPTION

In the tradition of striving for the highest quality and
reliability, Altec Lansing introduces the 1 753A Equalizer backed
by a vast knowledge of equalization technology. The 1753A
is designed to provide cost-effective accurate control for the
custom tailoring of frequency response in any professional or
industrial application.

Tre 1753A features 28 constant-Q active Band-pass
filters at the ISO preferred 1 / 3 octave center frequencies from
31.5 Hz to 16 kHz. Each filter section provides up to 12 dB of
boost or cut at its center frequency and is designed to skirt with
adjacent filters for minimum ripple and optimum combining
characteristics over a wide range of control settings. A 20 dB
gain control is provided to restore equalization losses that may
occur.

The variable high-pass filter, with a slope of 18 dB per
octave, allows adjustment of the system's lower cutoff fre-
quency from below 20 Hz to 160 Hz. The variable low-pass
filter also has a slope of 18 dB per octave and can operate
from 5 kHz to above 20 kHz, providing a smooth high-end roll
off. Other features include an automatic AC dropout bypass,
output muting that suppresses tum on/off transients, XLR and
barrier strip input and output connectors, and electronically
balanced input and output circuitry. The universal power trans-
former permits 100, 120, 200, 220, 240 Vac, 50/60 Hz
operation. In case of AC power loss, the capability of silently
switching to DC battery power is provided by a barrier strip
connector on the rear of the chassis. There are two optional
plug-in isolation transformers available: the 15550A input
transformer and the 15560A output transformer.

The Altec Lansing Model 1753A Equalizer is the choice
among professionals where precision graphic equalization is
required.

Page 2

Input

SPECIFICATIONS (continued)

Power requirements:

(reference 0 dBv = 0.775 Vrms) AC: 100, 120, 200, 220, 240 Vac, 50/60 Hz,
Type: Electronically balanced. 10 Watts.
Impedance: 30 kohms balanced. DC: Bipolar 24/28 Vdc at 200 mA (auto-
15 kohms unbalanced. matic transfer to DC mode if AC power
Nominal level: 0dBv (0.775 Vrms). fails)
Output: Operating Temperature
(reference 0 dBm = 0.775 Vrms across 600 ohms) Range: Up to 60°C (140°F).
Type: Electronically balanced.
Impedance: 44 ohms balanced. Dimensions:
22 ohms unbalanced. Height; 3.5 inches (8.9 cm).
Maximum level: +24 dBm. Width: 19.0 inches (48.3 cm).
Depth: 9.75 inches (24.8 cm).
High-Pass Filter: Variable low frequency cutoff from
below 20 Hz to 160 Hz with slope of Weight:
18 dB per octave. Net: 10.7 lbs (4.9 kgs).
Shipping: 140 lbs (6.0 kgs).
low-Pass Filter: Variable high frequency cutoff from 5
kHz to above 20 kHz with slope of 18 Enclosure: Rack-mount chassis.
dB per octave. 18 GA steel main chassis.
18 GA steel top, sides, rear cover.
controls: 28 center detented slide controls at 3/16 inch (0.5 cm) aluminum front
1/3 octave ISO centerfrequencies panel
from 31.5 Hz to 16 kHz, :12 dB boost
or cut. Color: Black.
Gain, High-pass filter and Low-pass
filter controls. Accessories: 10402 Perforated Security Cover.
AC power switch (bypasses 1153A 1555M Input Isolation Transformer.
when shut off). 1556M Output Isolation Transformer.
connecTIWS= Altec Lansing continually strives to improve its
Input: Fem? XLR- products and their performance. Therefore, specifica:
Barrier strip. tions are subject to change without any advance notice.
Output: Male XLR.
Barrier strip.
AC power: IEC power cord receptacle.
DC power: Barrier strip.
Block Diagram of 1753A
INPUT JUMPER WFFER fling JLMPER s W
9 +
t : JUMPER new ocnve muses 3; fig .{ > am, 13-04 8 -

@

315

Mount. 1553)

GAIN

FREQ FREQ

LINE newsman

m
Hz

.Iev

3i:

OPTIONAL 15560
LINE IRANSFORMEH

nEuv
clnctur