Altec Lansing Anniversary Series Training manual
9444B
and
9444B/SA
Anniversary
Series
Power
Amplifier
Operating
and
Service
Instructions
ALTEC
LANSING®
CORPORATION
II
MARK
IV
compuuy
P.
O.
Box
26105
•
Oklahoma
City,
OK
«
73126-0105
USA
®
Tel:
(405)
324-5311
•
FAX;
(405)
324-8981
operating
and
Service
Instructions
for
the
Altec
leLnsing
9444B
Power
Amplifier
Table
of
Contents
1
EU^CTRICAL...
1.1
120
V
ac>
50/00
TTz
Power
Goiiuections
...
-...
.
1.2
220/240
V
ac,
50/60
Hs^
Power
Connectioiis
....
2
INS
TAl.lJ
^TTQN..
.........
-
-
-...
2.1
Eack
Mounting
-........
2.2
V&ntilatioii
.....
3
SIGNAL
CONNECTIONS
....-
--
-
3.1
Input
Conn^tiona......
3.2
Line
Output
Connections
-..
-
*.
.....
3.3
Output
Connections
......
3.4
Output
Cable
Selection.......
3.4.1
CaJeulating
Power
Losses
with
8
ohm
Loads......
3.4.2
Calculating
Power
Losses
with
4
ohm
Loads
.
.
-
.
....
6
3.5
Damping
Factor
...
......................
......
3.5.1
C
alculating
the
Maxunum
Length
of
Gable
for
a
Specified
Damping
Factor
..............
3.6
Speaker
Protection
Fuse
Selection
..-
..
4
3.7
Compression
Driver
Protection
Capacitors
....
4
OCTAL
ACCESSORY
SOCKETS..
.
....-
-
□
5
PROTECTION
SYSTEMS
......
5.1
Load
Prot^tion
Cireuitiy
....
5.2
Amplifier
Protection
Circuitry.....
5.3
Protect
Indicator...
.
.
.
.....
6
OPERATION_______
______
6.1
Dual
Mode
of
Operation.........
6.2
Bridge
Mode
of
Operation
....
7
IN
CASE
OF
PROBLEMS
..........
8
SPECIFICATION.......
..
S
9
SERVICE
INFORMATION........
9.1
Trimpot
Adjustments
.......
^2
9.2
Equipment
Needed.-......
...
12
9.3
Adjusting
R39,
the
LF
Cancel
Trimpot
.....
’!
9.4
Adjusting
R26,
the
BIAS
Trimpot...
.
,
.
.......
i
2
9.5
Adjusting
R23
and
R24,
the
Negative
and
Positive
Current
Limit
Trimpots..
i
9.6
Checking
the
Short
Circuit
Current
...
...
...
i
^
9.7
Ordering
Replacement
Parts
........
1
_
9.8
Factory
Service
.......
9.9
Technical
Assistance
..........
10
THE
9444B/SA
.........
i
ALTEC
LANSING^
CORPORATION
®
a
IV
Company
operating
and
Service
Instructions
for
the
Altec
Lansing
9444B
Power
Amplifier
1
ELECTRICAL
Two
amplifier
models
are
available*
One
model
has
a
50/60
Hz
power
transformer
with
two
120
V
ac
primal^
windings.
These
windings
may
be
wired
in
parallel
or
series
for
operation
at
either
120
V
ac
or
220/240
V
ao_
The
ot*
her
amplifier
model
is
for
export
into
countries
where
the
ac
line
voltage
is
100
volts,
50/60
Hz,
The
next
two
sections
refer
to
the
first
model
with
the
dual
120
V
ac
pri¬
mary
windmgs,
1-1
120
V
ac,
50/60
Hz
Power
Coimectioiie
The
amplifier
is
provided
with
the
primary
of
the
power
tra¬
nsformer
strapped
for
120
V
ac
operation
from
the
factory*
Refer
to
Figure
2a
for
the
wiring
details.
WARNING:
Verify
that
the
power
transformer's
primary
circuit
configuration
is
correct
for
the
intended
ac
line
voltage
BEFORE
applying
power
to
the
amplifier,
1.2
220/240
V
ac,
60/60
Hz
Power
Connections
The
power
transformer
has
two
120
volt
primary
windings
which
can
be
connected
in
parallel
for
120
V
ac
Hne
voltages,
or
in
series
to
meet
220/240
V
ac
requi¬
rements-
Use
the
following
pro¬
cedures
to
re-strap
the
primary
of
the
power
transformer
for
220/240
V
ac
applications*
1*
Make
sure
the
amplifier
is
not
connected
to
any
po¬
wer
source,
2*
Remove
and
save
the
ele¬
ven
screws
securing
the
top
cover.
There
are
three
screws
on
each
side
and
three
along
the
top-rear
edge
of
the
chassis.
In
addition,
you
must
remove
the
two
innermost
screws
inset
into
the
top
bumper
strip.
Refer
to
Figure
1
for
the
exact
screw
locations.
Figure
1
Top
Cover
Removal
3.
Locate
terminal
blocks
TBl
and
TB2
on
the
side
of
the
chassis
near
the
rear
input
PC
board.
Re-
comueet
the
leads
as
shown
in
Figure
2b.
4-
Install
the
lop
cover
with
the
eleven
screws
previ¬
ously
removed.
Two
scr¬
ews
are
longer
than
the
others
removed
from
the
sides
and
rear.
These
longer
screws
install
into
the
rearmost
position
on
eacli
side
of
the
chassis.
5.
Install
an
5A
fuse,
Liiieb
fuse
Type
SAB
5A/2S0V
sio-blo
326-series
ceramic
body
or
equiv.
2
INSTALLATION
2-1
Rack
Mounting
The
amplifier
xniiy
be
in¬
stalled
in
a
stand:
-
!
19
inch
equipment
rack.
It
■
luires
5W
inches
of
vertical
rac>
r^-pace
and
secures
to
the
rack
:
binet
with
the
four
rack
moun^
screws
and
cup
washers
provide-’’:
the
hard¬
ware
kit.
2.2
Ventilation
The
amplifier
must
be
ad¬
equately
ventilatfju
avoid
ex¬
cessive
temperatur
It
should
not
be
used
in
area,
where
the
ambient
tempersTurf
exceeds
60
(140
®F).
To
deteruiine
the
am¬
bient
air
temperat
ure:-,
operate
the
^stem
in
the
rack
u\
U
the
temp¬
erature
stabilize:;.
Measure
the
ambient
air
with
a
uulb-type
ther¬
mometer
held
at
tlie
'jotiom
of
the
uppermost
amplifier.
Do
not
let
the
thermometer
tm
:h
the
metal
chassis
because
the
c:iiasgis
will
be
hotter
than
the
ambient
air.
If
the
ALTEC
LANSING^
CORPORATION
•
a
Mark
IV
Company
1
Operating
and
Service
Instructions
for
the
Mtec
Lansing
9444B
Power
Amplifier
Figure
2
Primary
Wiring
ConfiguratioB
for
120
V
ac
and
220^40
V
ac
air
temperature
exceeds
60
(140
the
equipment
sJhouId
bo
spaced
at
least
1-75
inches
apart
or
a
blower
installed
to
provide
sufficient
air
mov^ent
within
the
cabinet.
WARNING:
Do
not
operiite
the
amplifier
within
a
completely
closed
unventilated
housing,
3
SIGNAL
CONNECT¬
IONS
3,1
Input
CormectloBS
Balanced
input
connect¬
ions
may
be
made
to
either
the
barrier
strip
or
the
female
XLR
connectors.
For
single-ended
in¬
puts,
strap
the
low
(—)
input
to
ground
(pin
3
on
XLR),
Other¬
wise,
the
electronically-balanced
input
stage
wib
see
6
dB
less
in-
put
signal
level
than
with
a
bal¬
anced
input-
Refer
to
Figure
3
for
typical
input
connections.
3*2
Line
Output
Connect¬
ions
The
XLR
and
barrier
strip
connectors
are
wired
in
paraUeL
Pin
2
of
the
XLR
is
the
(+)
input
on
the
barrier
strip,
and
pin
3
is
the
(—)
input.
Since
the
input
im¬
pedance
of
the
electronically-
balanced
input
stage
is
high
(15
kolims),
there
is
min
imal
loading
on
the
signal
source.
When
the
input
connections
are
made
to
one
connector,
the
other
may
be
used
as
an
auxiliaiy
line
output
to
other
high
input
impedance
equip¬
ment,
Refer
to
Figure
3
for
poss¬
ible
applications,
3^3
Output
Connections
Output
connections
are
made
to
the
four
terminal
barrier
strip
connector
located
on
the
rear
of
the
unit.
Refer
to
Figure
4
for
typical
output
connectionE,
3.4
Output
Cable
Selects.
Speaker
wire
si2:e
playrs
a-
important
part
in
quality
sot
systems.
Small
wire
gauges
ci
i
waste
power
and
reduce
the
dar
-
ping
factor
at
the
speaker
ter
i-
inals.
This
can
add
coloration
muddio^s
to
the
sound.
To
ii*-
offset
this
problem.
Table
I
in
been
assembled
to
enable
yov,
calculate
the
power
losses
in
speaker
cable,
3.4,1
Calculating
Powe
Losses
with
8
Loads
To
calculate
the
tot
power
loss
in
the
speaker
caij.
multiply
the
power
loss
per
Cor
meter)
of
the
2-wire
cal
selected
from
Table
I
by
length
of
the
cable
in
feet
meters).
For
example,
suppose
installer
uses
160
feet
of
10
GA
wire
c^le
with
an
8
H
^stem.
The
total
power
loss
the
cable
is:
Total
Power
Loss
in
cable
-
0,0509
watWfoot
x
160
feet
—
8,2
watts
Does
this
mean
that
whenever
amplifier
produces
200
watt-
output
power,
191,9
waits
(2i
watts
minus
8.1
watts)
will
Oi:
delivered
to
the
8
ohm
load?
Tlie
actual
load
impedance
is
ohms
plus
the
resistance
of
•
cable
(0.00204
ohms/foot
160
feet)
for
a
tot^ll
load
imp^
dance
of
8,3264
ohms.
At
the
8
rated
output
power,
the
outpu
voltage
is
40
V
rms.
Therefor
the
amplifier
produces
192,2
wax.;
with
this
load
instead
of
20f
watts.
This
was
calculated
squaring
the
voltage
and
dividi;
,
by
the
load
impedance
{40^
div;
ed
by
8.3264
ohms).
As
a
resuii.
the
actual
power
delivered
to
‘
load
is
184A
watts
(192,2
wa:
minus
8.1
watts).
2
ALTEC
LANSING^
CORPORATION
•
a
Mark
IV
Company
Operating
and
Service
Instructions
for
the
Altec
Lansing
9444B
Power
Amplifier
SOURCE
AMPLIFIER'S
IKPUTS
AUX
OUTPUTS
Figure
S
laical
Input
Cannections
AMPLIFIER'S
OUTPUTS
LOUDSPEAKER
LOADS
Figure
4
Typical
Oatpui
Connections
Had
IS
GA
wire
been
used
in
the
above
example,
the
loss
in
the
cable
would
have
been
51*9
watts*
This
example
illustrate
the
im¬
portance
of
using
the
proper
wire
size.
S.4.2
Calculating
Power
Losses
with
4
ohm
Loads
To
calculait
the
losses
when
using
a
4
ohm
spi^aker
as¬
tern,
multiply
the
at
3
ohms
by
3.
In
the
above
exair.
i
!
-,
the
10
GA
wire
would
com
me
24*3
watts
of
power
while
18
GA
wire
wotild
waste
15v
7
watts
-
more
than
half
of
tke
arrtplifier^s
4
ohm
power
raiin^^
3-5
Damping
Factor
The
higher
tht
diiinping
factor
rating
of
an
ajni
liflerj
the
greater
the
ability
of
ampliiier
to
control
unwanted
s\
-
iiker
cone
movements.
When
a
sigiml
drives
a
woofer,
current
flowii^
through
the
voice
coil
creates
Miagneiic
field.
This
Geld
inter;-.
with
the
permanent
magnetic
in
the
gap
and
forces
the
v'fnbmation
cone
and
voice
coil
ar
^enibiy
to
move
outward.
When
'
signal
is
removed^
the
asseinbl-.
moves
in¬
ward
hut
its
momefitu
ill
causes
it
to
overshoot
its
resting
licunt.
This
overshoot
will
dampen
itself
out
eventually
but
the
uir
nted
mo¬
vements
can
add
consitiex^ble
dis-
tori
ion
products
to
ih-
;’Ound*
In
the
process
of
moving
inward
through
the
magni-'
ic
field,
the
voice
coil
assembh^
aerates
a
current
of
opposite
poinrity
to
the
original
signal.
Tiiiti
current
induces
a
voltage
or
“back
EMF'*
which
travels
through
the
speaker
wire
to
the
ampliiler*s
output*
The
lower
the
ampUni
r
k
output
impedance,
the
faster
the
over¬
shoot
of
the
voice
coll
will
dampen
out.
The
output
impetjanoe
of
an
amplifier
can
be
calc
ulated
by
dividing
the
rated
cputput
impe¬
dance,
typically
S
nhms,
by
the
damping
factor.
The
has
a
damping
factor
rating
of
200
which
correspond:
ll*
an
output
impedance
of
0.04
ohnis,
3.5-1
Calculating
the
Maximo
m
Length
of
Cable
for
n
Specified
ALTEC
LANSING^
COJ?PORAT/OiV
•
a
AfarJt
IV
Company
Operating
and
Service
InBtructions
for
the
Altec
Lansing
9444B
Power
Amplifier
Damping
Factor
Spec¬
ification
at
the
Load
The
damping
factor
rating
is
typically
never
realiml
at
the
load
because
of
the
resistance
of
the
cable
(and
other
factors
such
as
tlie
contact
resistance
of
an
output
relay
or
the
resistance
of
an
output
fuse)-
The
damping
fac¬
tor
at
the
load
should
be
30
for
general
paging
systems
and
50
for
high
fidelity
music
systems.
Econ¬
omics
usually
dictate,
however,
that
these
numbers
are
cut-in-
half,
The
resulting
damping
factor
at
the
load
should
be
based
on
experience
and
customer
satis¬
faction,
Once
a
minimum
damping
factor
is
determined
for
a
partic¬
ular
type
of
installation,
the
fo-
ilowing
equation
can
calculate
the
maximum
length
of
2-wire
cable
which
can
be
used
to
achieve
the
minimitm
damping
factor
specified
at
the
load:
Max.
Length
of
2-wire
cable
in
feet
ZL
—
Zo
-
JDF_
DCK/ft
where
ZL
is
the
load
impedance
to
connect
to
the
amp¬
lifier;
Zo
is
the
amplifier's
output
impedance
(0,04
ohms
for
the
9444B);
DF
is
the
minimum
permissible
damping
factor
at
the
load;
aiwl
DCR/ft
is
the
DC
resis¬
tance
of
the
2-wb:e
cable
per
foot
from
Table
L
The
same
equation
can
be
used
to
calculate
the
maximum
cable
leng¬
th
in
meters
by
substituting
the
DCR
per
meter
value
from
Table
L
Let's
use
the
equation.
Suppose
ZL
equals
8
ohms,
Zo
=
0,04
ohms,
and
the
minimum
damping
Table
I
9444B
Power
Losses
in
2-wire
Speaker
Cable
Power
Cable
Crni$a-
Power
AWO
DCB/n.
Losa/n
Soclioinil
DCR/Jiieter
LDSs/rR.CtilJ
(GA)
(O/a)
(watWft)
Biva
(mm^)
(n/m)
0.00081
0.0201
13.30
0.00264
0.0661
8
0.00X21
omm
S.3ti
0.00421
0-1051
10
0.00204
0.0509
5.26
0.00669
0.1669
12
0.00324
0,0809
3.S1
001003
0.2650
14
0.00515
0.1280
3.08
0.01691
0-4210
16
0.00819
0.2043
1.31
0.02685
0.0067
18
0.01302
0.3244
0.82
0.042S9
1.0609
20
0.02070
0.5148
0.52
0.06764
1.0627
22
0.03292
0,8163
0.33
0
10658
2.5950
factor
at
the
load
is
25,
in
add¬
ition,
18
GA
cable
is
preferred.
Then,
the
maximum
length
of
18
GA
cable
which
can
be
used
to
achieve
a
damping
factor
of
25
at
the
load
is;
8
—
(G,04>
^5_
=
2L5feet
0.01302
n/ft
Sometimes
it
may
be
oec^sary
to
locate
the
speaker
100
feet
or
more
away
fiom
the
amplifier-
In
this
situation,
a
much
larger
gauge
cable
is
required.
However,
this
may
not
be
practical
or
eco¬
nomical.
The
size
of
the
2-wire
cable
can
be
greatly
reduced
by
stepping
up
the
output
voltage
of
the
amplifier
to
70,
100,
140,
or
210
volt,
uaing
an
output
trans¬
former,
then
stepping
down
the
voltage
at
the
load.
Such
a
system
is
shown
in
Figure
5,
The
maximum
length
of
2-wire
ca¬
ble
in
this
situation
can
be
ap¬
proximated
from
the
following
equation:
Max.
Length
of
2-wire
cable
in
feet
1
Zq
(Pout)(DCR/ft)
DP
ZL
where
V
is
the
stepped-up
age
of
the
fystem;
Pout
is
the
mted
outpi
*
power
of
the
amplifier:
Zo
is
the
output
imp
ance
of
the
amplifier
(O.C
ohms
for
the
ZL
is
the
load
impeda
-
IKJR/ft
is
the
DC
tance
of
the
2-wire
cal:
per
foot
from
Table
I;
DF
is
the
minimum
p
missible
damping
facto:
the
load.
Suppose
a
210
volt
system
iver
used
at
a
600
watt
power
level
drive
an
8
ohm
load
with
a
mi
i
mum
damping
factor
of
25,
Usin^
the
same
18
GA
cable
as
befo^
the
maximum
Length
can
now
198
feet.
Power
companies
Wr.
this
technique
to
transfer
larga
amounts
of
power
over
great
di
^
tances.
3.6
Speaker
Protectioj
Fuse
Selection
Sometimes
it
may
be
des¬
irable
to
use
in-line
fuses
(fuses
ir
series
with
the
output)
to
protect
loudspeaker
^sterns
(or
the
am;
lifier).
It
is
difficult,
however,
determine
the
proper
fuse
value
with
the
correct
time
lag
au:.
overload
characteristics
to
match
the
limitations
of
a
speaker
sys-
tern.
The
values
shown
in
Table
!!
should
serve
only
as
a
guide,
T:
4
ALTEC
LANSING*
CORPORATION
•
a
Mark
IV
Company
Operating
and
Service
Instructions
for
the
Altec
Lansing
9444B
Power
Amplifier
Figure
5
High-voltage
Distrihution
System
use,
determine
iJie
power
rating
and
load
value.
Then,
^lect
a
standard
value
fuse
of
the
next
smaller
value
to
the
one
listed
in
the
table.
Table
n
Calculated
Output
Fuse
VEdues
Power
da
sn
jsa
(wtttta)
Load
Lead
100
5.70
2.62
1.85
150
4.54
5.2i
2.27
200
5.24
3.70
a.G2
300
6.42
4.34
3.21
400
7.41
5.24
3-70
600
9.07
6.42
4.54
The
values
are
calculated
for
fast-
blow
fuses
which
carry
135%
of
their
current
rating
for
an
hour
but
will
blow
within
1
second
at
200%,
Other
fuse
values
may
be
calculated
for
different
power
levels
from
the
following
equation:
Fuse
value
=
(Pout
X
ZL)
^
amps
ZL
X
1.35
where
Pout
is
the
output
power
rating
of
the
amplifier;
and
ZL
is
the
load
impedance.
Use
32
volt
fuses
if
possible;
they
typically
have
the
lowest
internal
resistance
which
will
help
mini¬
mize
deterioration
of
the
doping
factor
at
the
load.
Refer
to
the
example
in
Figure
4,
3.7
Compression
Driver
Protection
Capacitors
Compression
drivers^
used
for
mid
to
high
frequency
sound
reproduction,
are
much
more
sus¬
ceptible
to
damage
from
low
fre¬
quencies
than
large
cone
loud¬
speakers.
Even
though
an
elect¬
ronic
crossover
may
be
employed,
problems
may
arise
in
the
cables
between
the
crossover
and
the
power
amplifier,
or
from
misad-
jnstment
of
the
crossover.
Either
of
these
situations
could
apply
low
frequency
signals
or
hum
to
the
driver
and
cause
damage.
To
pre¬
vent
a
potential
mishap,
Altec
Lansing
recommends
using
a
cap¬
acitor
between
the
amplifier
and
the
compression
driver
lo
supp¬
ress
low
frequencies
and
^
Gssible
DC,
Refer
to
the
eKamp;
■
in
Fig¬
ure
4.
In
choosing
a
value,
must
be
careful
not
to
interfer
with
the
crossover
frequency.
A*
a
jcneraZ
rule,
sefeef
a
capac^:c^
whose
break
frequency,
with
r^pect
to
the
load,
is
3
dB
down
at
appnxdmuie-
iy
Vs
of
the
high
omer
/ne-
quency.
Mylar
capacitors
witli
least
a
100
volt
ac
rating
are
ra:
-umend-
ed.
Table
lU
shows
recom¬
mended
capacitor
val.
-
for
use
with
8
and
16
ohm
dri’
^rs
at
pop¬
ular
crossover
frequencies.
Table
HI
Driver
Protection
Capacitors
Crossov,!-
sa
ten
Fmiueniv
Drivor
Drivner
SOO
Hz
m
pT
40
(iF
800
Hz
50
pr
25
|iF
1000
Hz
40
jtF
20
t.F
1250
Hz
33
iiF
i6jiF
2000
Hz
20
pjT
10
i*F
3150
Hz
12
jlF
6m.F
6300
Hz
6
jii
3
|iF
4
OCTAL
ACCESSORY
SOCKETf
Two
octal
sockets
permit
a
variety
of
plug-in
acppr
jori^
to
be
used
with
the
amplifier
Normally,
one
"U”
jumper
Is
^
-inerted
bet¬
ween
octal
socket
pins
8
and
1,
and
another
betwixt:
*
i
ns
7
and
6.
These
jumpers
must
remain
in
plctee
for
the
amplii
rr
to
operate
when
not
using
accessory
modules.
To
use
with
in
accessory
module,
remove
r
.
save)
the
jumpers
and
insb.r
:he
module
making
sure
the
kev
o
its
center
post
aligns
with
tlis
roove
m
the
female
socket.
For
r
^ration,
refer
to
the
instructions
Tovided
with
ALTEC
LANSING^
CORPOitAT/OAT
o
a
Mark
IV
Company
5
Operating
and
Service
Instructions
for
the
Altec
Lansing
9444B
Power
Amplifier
the
module.
Schematically,
the
module
will
bo
inserted
between
the
input
connector
and
the
bal-
anced
input
stage.
Electronic
modules
are
powered
from
a
bipolar
15
vplt
supply
in
the
amplifier,
'Hie
supply
is
cap¬
able
of
supplying
up
to
25
ma
DC
of
current.
Currents
in
excess
of
25
ma
DC
may
prevent
the
ampli-
Ger
from
diseng^ing
from
its
built-in
protection
meciianisms.
5
PROTECTTON
SYS¬
TEMS
5.1
Load
Protection
Cir¬
cuitry
Each
channel
independ¬
ently
protects
its
Ic^d
from
startup/shutdown
transients,
DC,
and
large
subsonic
signals.
5.2
Amplifier
Protection
Circuitry
A
unique
current-limiting
circuit
was
designed
specifically
for
the
amplifier.
It
features
a
variable
ciirrenl
limit
which
is
a
function
of
the
output
signal
volt¬
age,
As
a
result,
tlie
amplifier
can
deliver
the
rated
currents
into
rated
loads
but
substantially
lim¬
its
the
current
into
low
impedance
or
shorted
loads
(diorted
output
terminals).
Once
the
short
is
re¬
moved,
however,
the
amplifier
will
resume
normal
operation.
A
dual
speed
fan
is
also
incorp¬
orated
to
provide
efficient
cooling
under
the
most
demanding
condi¬
tions.
When
the
heatsink
temper¬
ature
at
the
fin
tips
reaches
ap¬
proximately
88
^
(190
TP')>
the
fan
automatically
switch^
to
high
speed
operation.
As
the
temper¬
ature
cools
to
approximately
78
®C
(172
"F),
low
speed
operation
is
once
again
reamed.
The
heatsink
is
also
thermally
equalized
to
prevent
the
output
devices
nearest
the
fan
from
op¬
erating
at
a
cooler
temperature
than
the
devices
at
the
opposite
end.
Tills
minimizes
the
thermal
gradient
across
the
heatsink
and
forces
the
devices
to
operate
at
more
nearly
the
same
tempera¬
ture,
Tills
equalizes
the
lifetimes
and
reliability
characteristics
of
the
output
devices
so
that
no
one
device
becomes
the
weak
link
in
the
chain.
Should
the
hmtsiiik
temperature
of
a
channel
remain
excessively
high,
the
affected
channel
will
shut
down
automatically.
When
the
output
devices
cool
to
a
safe
operating
temperature,
the
chan¬
nel
will
automatically
resume
normal
operation-
5.3
P
rotect
Indicator
The
‘TROTECT”
LED
does
not
tiirn*on
abruptly
as
others
may
do;
its
intensity
is
allowed
to
vary.
As
a
result,
its
degree
of
brightness
serves
as
a
relative
indicator
of
the
severity
of
the
current
operating
conditions
e.g.,
the
bri^ter
the
LED,
the
greater
the
stress
on
the
chan-
nel(sj.
This
provides
a
visual
not¬
ification
well
in
advance
of
any
impending
shutdown.
Although
the
channel
may
still
operate
with
the
LED
apparently
at
full
brightness,
a
total
shut¬
down
will
occur
within
a
few
sec¬
onds
unle^
the
operating
condit¬
ions
improve.
If
a
shutdown
does
occur,
the
channel
will
resume
normal
operation
as
soon
as
its
devices
have
cooled
to
an
accept¬
able
temperature.
0
OPERATION
6.1
Dual
Mode
of
Oper¬
ation
In
the
dual
mode
of
oper¬
ation,
the
channels
may
be
oper¬
ated
independently.
After
install-
ation
and
hookup,
verify
that
the
mode
switch,
located
on
the
rear
panel,
is
in
the
**DUAL”
position
and
rotate
the
level
controls
fully
counterclockwise
(full
attom.
ion).
Input
a
0
dBo
(0-775
V
nominal
signal
level
and
power.
Slowly
increase
the
controls
until
the
desired
oui
power
is
obtained.
If
ci
^^CLIP”
LED
illuminates,
red
the
output
with
the
channel
lev
control
or
reduce
the
input
eigi
level
at
its
source.
WARNING:
Never
attempt
o
nect
the
outputs
of
the
two
cka
nels
in
parallel.
6,2
Bridge
Mode
of
Op-
ation
After
installatian
hookup,
verify
that
the
mt
switch,
located
on
the
rear
pan?
is
in
the
“BRIDGE’’
position,
h
ate
both
levels
controls
fi
.
counterclockwise
(full
atteiin;:
ion).
Input
a
0
dBu
(0.775
V
r:
noniinal
signal
level
into
chan:^
1
only
and
apply
power.
Slowly
crease
the
level
control
of
char
.
1
until
the
desired
output
povv
is
obtained-
If
either
“CLIP”
LK
illuminates,
reduce
the
output
le
el
with
the
level
control
or
redur
the
input
signal
level
at
its
sou:
CAUTION:
Be
sure
that
no
inp'
connectioTis
are
made
to
ehannc:
and
that
its
level
control
is
fut
counterclockwise
(OFF).
WARNING:
The
bridged
outp:
mode
provides
a
true
balanced-tf
ground
output
Do
not
use
any
tei
equipment
to
test
or
evaluate
tk^
amplifier
which
does
not
ha’
floating
grounds.
7
In
Cajse
of
Problems
Please
check
the
foUowii..
items:
1.
Verify
that
the
amplifier
is
properly
connected
an
ac
power
source
an^
that
the
source
is
active.
2,
Verify
that
the
input
con¬
nections
are
proper.;
6
ALTEC
LANSIN<?^
CORPORATION
•
a
Mark
IV
Company
Operating
and
Service
Instructions
for
the
Altec
Innsing
9444B
Power
Amplifier
made.
Refer
to
Figure
3.
3.
Verify
that
the
output
connections
are
properly
made.
Refer
to
Figure
4.
4.
Check
the
input
and
out¬
put
cables
for
proper
wiring
and
continuity,
5.
Check
the
signal
source
and
the
load.
6.
Insure
that
the
two
jump¬
ers
for
each
octal
socket
are
properly
installed
(if
not
using
optional
plug-in
modules)-
7.
Insure
that
any
accessory
modnles
installed
do
not
draw
more
than
25
ma
DC
of
current,
8.
Check
that
the
mode
switch
is
in
the
desired
position,
NOTICE:
Repairs
perfoT-med
by
other
than
authorized^
worranty
stations
(Declers)
or
qudlified
persofiTtel
shall
void
the
w<xrrajity
period
of
this
unit
To
avoid
loss
of
warranty^
see
your
nearest
Alt^
Lansing
authorized
dealer^
or
call
Altec
Lansing
Customer
Service
directly
at
(405)
324^5311^
FAX
(405)
324-8981,
or
uirite:
Altec
Lansing
Customer
Service/Repair
10500
W,
Reno
Oklahoma
City,
OK
73128
U,ISA,
ALTEC
LANSING^
CORPORATION
«
a
Mark
IV
Company
7
operating
and
Service
Instructions
for
the
Altec
Uinsing
9444B
Power
Amplifier
8
SPECIFICATIONS
Bridge
mode,
8
or
16
Q;
39
dB
Conditions:
1.
0
dBu
-
0<775
volts
rms.
2.
Dual
mode
ratings
are
for
each
charmeL
3.
Both
channels
operating
at
rated
output
power
unless
noted.
4.
120
volt
ac
line
input
voltage
maintained
for
all
tests
unless
noted.
Continuous;
Elated
Output
Power:
(20
Hz
-
20
kHz
at
less
than
0-1%
THD)
Dual
mode,
4
fl:
300
watts/ch
Bridge
mode,
8
A:
600
watts
Dual
mode,
8
A:
200
watts/ch
Bridge
mode,
16
A:
400
watts
Input
Sensitivity
for
Rat«d
Output
Power;
(Ret
1
kHz,
±0.15
dB)
Dual
mode,
4
A:
±0.1
dBu
(0.78
V
nn
>
Bridge
mode,
8
A:
+0.1
dBu
(0.78
V
rm:v
Dual
mode,
8
A:
+1.2
dBu
(0.89
V
rm."
Bridge
mode,
16
A:
+1.2
dBu
(0.89
V
rm
Maximum
Input
Level:
+20
dBu
(7.75
V
rme
(Ref,
1
kHz)
input
Impedance:
(Ref.
1
kHz)
Balanced;
15
kA
Unbalanced:
15
kA
Continuous
Rated
Output
Power
to
Subwoofer:
(20
Hz
-
1
kHz
at
less
than
0.1%
THD)
Dual
mode,
4
A:
375
watts/ch
Bridge
mode,
8
A:
750
watts
Dual
mode,
8
A:
225
watts/ch
Bridge
mode,
16
A;
450
watts
Polarity:
Positive-going
sign
applied
to
pin
2
of
or
{+)
of
barrier
st.
produces
positive-gf
signal
at
(+)
oirt-p
terminal.
Maximum
Midband
Output
Power:
(Ref.
1
kHz,
1%
THD,
@120
volts
ac
line
volUge)
Dual
mode,
4
A:
>400
watts/ch
Bridge
mode,
8
A:
>800
watts
Dual
mode,
8
A:
>250
watts/ch
Bridge
mode,
16
A:
>
500
watts
(Ref.
1
kHz,
1%
THD,
@108
volts
ac
(10%
sag))
Dual
mode,
4
A:
>325
watts/ch
Bridge
mode,
S
A:
>650
watts
Dual
mode,
8
A:
>200
watts/ch
Bridge
mode,
16
A;
>400
waits
(Ref
1
kHz,
1%
THD,
@100
volts
ac
(17%
sag))
Dual
mode,
4
A:
>230
watts/ch
Bridge
mode,
8
A:
>460
watts
Dual
mode,
8
A:
>
176
watts/ch
Bridge
mode,
16
A;
>350
watts
Headroom
(Before
clip):
^
1
dB
(Ref.
1
kHz,
1%
THD,
any
mode)
Frequency
Response;
10
Hz
-
90
kHz
(Ref.
1
kHz,
1
watt
output,
+0/—3
dB)
Power
Bandwidth:
20
Hz
-
20
kHz
(Ref
1
kHz,
+0/—1
dBr
where
0
dBr
=
rated
output
power
in
any
mode)
Voltage
Gain:
(Ref.
1
kHz)
Dual
mode,
4
A
or
8
0;
33
dB
<+
2
5
^
>-^
15
"
<
0
.
1
%
{Typ.
<
0
.
01
%
measurement
bandwidth)
Phase
Response:
(Any
mode)
20
Hz:
20
kHz:
THD:
(Any
mode,
30
kHz
IMD
(SMPTE
4:1):
(Any
mode)
TIM
(DIM
100):
(Any
mode)
Rise
Time:
(Any
mode,
10%
to
90%)
Slew
Rate:
Dual
mode,
4
or
8
A:
Bridge
mode,
8
or
16
A:
Damping
Factor;
(Dual
mode,
8
A)
20
Hz
-
1
kHz:
20
kHz:
<0.05%
(l^p.
<0S)m
<0.05%
<6
psec
>30
V/psac
>60
V/psec
>200
>76
Crosstalki
<76
dBr
(Ref
1
kHz,
0
dBr
—
rated
output
power
into
8
ohms,
single
channel
operating)
Noise:
>100
dB
(Below
rated
output
power,
A-weighting
filter,
S
8
ALTEC
LANSING^
CORPORATION
«
a
Mark
IV
Company
Operating
and
Service
Instructions
for
the
Altec
Lansing
9444B
Power
Amplifier
dual
mode,
50/60
liz
ac
Imo
frequency)
Amplifier
Protection;
Load
Protection;
Cooling;
Heatsink:
Fan:
Output
Topology;
Output
Type;
Dual
mode:
Bridge
mode:
Output
Devices:
Total
number:
Pdmax
rating:
Vcao:
Ic:
13
max:
Controls
and
Switches:
Rear:
Front:
Front
Panel
Indicators;
Connections;
Input:
Shorted
output
term¬
inals,
Over-temperature,
RF
interference
Startup/shutdown
trans¬
ients,
DC
faults.
Sub¬
sonic
signals
Thermally
equalized
3/16
in
aluminum
black
ano¬
dized
heatsink
Thermostatically
con¬
trolled
dual
speed
fan.
Approximately
50
CFM
at
low
speed
and
100
CFM
at
high
speed.
Ball
bearing
fan
lias
mini¬
mum
life
rating
of
50,000
hours
at
25
ambient
temperature
True
complementary
symmetry
with
grounded
collectors
(do
mica
insulators
meaiis
better
heat
transfer)
Unbalanced,
each
chan¬
nel
Balanced
16
devices
260
watts
250
volte
DC
16
am
ps
DC
200
Mode
switch.
Two
input
level
controls
Power
switch
Power
LED,
Clip
LED
(x
2),Protect
LED
(x
2)
6
terminal
barrier
strip.
Female
XLR
(x
2),
Octal
accessory
socket
(x
2),
powered
with
±15
Output:
Power:
Fuse
Type:
Power
Requiremeiits;
Operating
ac
Voltage
Range:
I/8th
max
midband
power:
l/3rd
max
midbarrf
power:
volte
DC
at
25
:
>u-
Barrier
strip
6
ft
C1-S3
--^-Tvire,
16
GA
power
:vid
with
NEMA
6-lp
;
:l-IEC
Littelfuse
Tvp-
10
A/250
V
Sl^njt:H§
326-
series
cerandc
cartridge
body,
or
equivaknt
(for
120
V
ac
UB^
‘'
120
V
ac,
50/6*
I
Hz,
1000
watte
(configurable
to
220/240
V
acL
:
X)
V
ac,
6
0/60
Hr
model
available.
Ope
rates
fr
^:
in
line
voltages
an
as
90
volts
Cat
reduc-Kl
output
power)
Bssiiining
a
120
V
ac
nominal
Itrv
,
720
watted.
100
kBTU/h
1,068
wi^i
13/2.702
kBTU/h
Rated
output
power:
1,464
W'
a
f.i.s/2.9
3
8
kBTU/h
Max
midband
power:
1,680
wiiiLs/2.873
kBTU/h
Operating
Temperature
Range:
Up
to
60
:
(140
T)
ambient
Dimensions
(Rear
of
rack
ears
to
nuis
depth):
5.25
in
K
X
]
9
in
W
x
13
in
D
(13.3
cm
i;
;l
-^8.3
cm
W
X
33
cm
DI
Power
Consumption/
Heat
PrcKluced;
(Both
channels
operating
in
dual
modf?
with
1
kHz
sinewavG
input
signal
at
stated
output
pG
.ver
into
4
n
loads)
idle:
72
watts/0.24'j
kBTU/h
ALTEC
LANSING^
CORPORATION
•
a
Mark
IV
Company
Operating
and
Service
Instructions
for
the
Altec
Lansing
9444B
Power
Amplifier
Shipping
Weight:
42
lbs
(19,1
kg)
Net
Weight!
34
lbs
(15,5
kg)
Colon
Black
Enclosure:
Rack
mount
chassis,
W
GA
steel,
3/16
in
5052
aluminum
alloy
front
panel
Standard
Accessories:
4
-
"U”
jumper
plugs
for
octal
sockets
(2
per
socket,
installed)
1
-
Operating
Instruct¬
ions
and
Service
Manual
1-5
A/250
V
fuse
(for
220/240
V
ac
use)
Optional
Accessories:
14712A
Power
Limiter
15515A
Input
Bridging
Transformer
with
Pad
10524A
300
watt
70
volt
Transformer
15525A
600
watt
70
volt
Transformer
15567A
300
watt
Auto¬
former
15581A
24
dB/oct
Linkwitz-RileyCrossover
15594A-XXS
18
dB/oct
Low
Pass
Filters
15595A-XXX
18
dB/oct
High
Pass
Filters
The
"-xxx”
represents
various
corner
frequencies
available
for
the
corresponding
filter,
ALTEC
LANSING
CORPORATION
continually
strives
to
improve
products
and
performance.
Therefore,
the
specifications
are
subject
to
change
without
notice.
Slo-Blo®
is
a
registered
trademark
of
Littalfuse,
Inc.
10
ALTEC
LANSING^
CORPORATION
•
a
Mark
IV
Company
This manual suits for next models
2
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