Ab international 712 a brochure

Page 1

ADVANCED
TECHNOLOGY
DESIGN SERIES

772A

BIAMPL/FIEFi

'67

O

nu-mrnnmnu O

_ o ...

W

G O

all
at

ADVANCED

DESIGN 35353
Q Q

o
'3,
a
S
0

J
. r 1
ADVANCED TECHNOLOGY SPECIFICATIONS
Advanced Technology Design Series IV from AB Tyoei 21%|"? 951?! with _
International is a modular system of high performance n ar 5'9 pmmss'ng
power amplifiers and electronic signal processing that Poweroutputfl LF: 500w at e (2
may be precisely tailored to the specific requirements of 1380 349
. w at 2 r2
professronal loudspeaker components.
HF: 150w at 8 Q
The experience gained from building three generations of Gain: 325 dB. LFAHF

signal~processing power amplifiers brings new features
and new standards of performance to ATD IV. The low
frequency power amplifier oi the 712A is fully
complementary and operates from a six«|evel logicgated
power supply that adapts to the input waveform to
provide only the DC rail voltages necessary for
undistorted amplification. The result is tremendous
output capability, cool operation and unconditional
stability over an unusually wide range of load conditions.
A delayed-ON, instant-OFF muting control circuit allows
internal supply voltages to stabilize before loudspeakers
are connected. Speaker connections are instantly
removed, should there be an interruption of AC power.

Included in the 712A are two apportioned power
amplifiers, selectable system high pass filters, precision
step attenuators, fourth-order Bessel active crossovers,
an adjustable all-pass delay network for LF-HF
time-phase correction at crossover, adjustable low
frequency Thiele-Small alignment equalization, balanced
and unbalanced inputs with looping provision and high
frequency power response compensation for
professional compression drivers.

For users desiring specific non-standard features and/or
signal processing, a wide range of options are available,
including high pass frequencies, crossover frequencies

and filter topology and HF power response equalization.

See 'Optional Equipment' brochure for details.

L

input sensitivity:2 1.5 Vrms (referred to rated 8:1 LF output)

input impedance: 15 kt), balanced or unbalanced
Noise level: 100 dB below rated outputs. unweighted

800 Hz, 4-pole (24 dB/octave)
Bessel response

Crossover:3

Signal processing:3 8 stem high pass (40 or 80 Hz) 2nd-order
derived w/adjustable underdamping for

assisted Thiele-Small alignments
Adjustable low-pass delay for LP output

Adjustable equalization for HF
power response compensation
Controls: Power, system level
L : Delay, level, high pass/E0
HF: level, EQ

XLR-S (bal) with loop-thru and ground "it
switch, 1/4-inch (unbal)

120/240 VAC, 50/60 Hz, 400w (avg)
1500 w (max)

51/4' (13.3cm) H x 19' (48.3cm) W x
131/2' (34.3cm) D; 42 lbs. (19.1 kg.)

Input connectors:
Power reqUirements:

Physical:

l. Continuous power output at less than DAV. THO. 20 Hz to 20 kHz. outputs normalized
lor full-range operation

2. With all level controls adjusted for zero attenuation. normalized response to a sweat
input signal Will be tier:

3. A_ wide range ol optional crossovers and signal processing IS avauable. Please relerto
'cptronat equipment for oalatls,

J

Page 2

r
FEATURES AND CONTROLS
HP EQ Hi h pass 0°" '1'" High lrequency EQ control and HF
-5 I 2 4 515 H 'v ° ' 2 4' liltger and indicators (left). The reen 'on' LED
z 7 associated EQ indicates presence 0 HF signal. while
fig EQ control N-- a .5 . a t . «a the red 'clip' LED shows true clippings
is at left. . z a a e 7 {Ease features are [fipeaEtad tortlée
LEVEL r- '1" \-n The hi h 5 '~' output channel. a provi as
One of the three pass 11an is 'in' 31 40 Hz ((19). QQE correction for driver power response.
precision level The E0 is ,
controls in the 712A. enabled, A Wide ran 6 of Options
Each switch position with 6 dB are avallab e. Shown is
is calibrated for dB boost. At 12 dB boost centered at
insertion loss, and right is the 14 kHz beginning at
the selected values response. 3.5 kHz for a popular 2'
sum directly. 12.5 dB with E0 in throat driver, with control
attenuation shown. and OUt- settings above.
0 0 / "'"V 0 Low lrequency delay control. Delay circuitry is included in the
°°' a I o LF output channel to correct for time-phase offsets between
0 m m 0 the LF and HF loudspeaker components. Switch positions
mm, are marked in radians relative to the low pass frequency. In
the example. 4.04 radians hfave Izegn selejcted, :vhifih
" . " oorrespon s to a p ysica 0 set in open en! 0 ct er
(ti-uh w \m{ considerations) equal to 10.7 inches at 800 Hz. With
W iiuuu'uii gfifimfi lounh-order (24 dB/octave) Bessel linear phase crossover
- :v m 1 2 a en filters, the 712A will deliver virtually
V V EL _ ' ' " '5 g 1 seamless, phase coherent response
,7 I in high-quality two-way loudspeaker
M EIE system applications. An 'in-out'
.4 switch allows immediate response
0 O 0 DELAY _ and listening comparisons, with and
mm" "mm"' Rama '3 without the delay compensation.
0 Mann ewpurisa maroon 0
¥ 4
( n
SIGNAL FLOW . = t [\Sig. Clip
/ / «om» / I/ (Is
/ HF Output
High Pass HF E0 Fixed EQ HF Level 150W
1
Balanced Input /
System
VED: Level Sig. Clip
1 R
v-[H \ A / i/ m
/ LF Output
LUnbalanced Input High Pass/E0 Low Pass Delay LF Level 500W
J
V \
APPEARANCE lllllllllllJUIlIlllIlIllllllllllUUllllJl
J m
L U U 1 guy/5* J
r H AB INTERNATIONAL ELECTRONICS, INC. (916)783-7800 fl
1830-6 Vernon Street, PO. Box 1105, Roseville, CA 95678

FAX:(91 6)784-1 050 J