Altec Lansing 9441A User Manual

^ ■ \

9441A

Anniversary Series Power Amplifier

O pe r at i ng an d S e rv i ce In s tr u ct i on s

ALTEC LANSING® CORPORATION

n MARK IV coiiipiiiiy

P. O. Box 26105 © Oklahoma City, OK • 73126-0105 USA © Tel: [phone] © FAX: [phone]b1

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

Table of Contents

1 ELECTRICAL

1.1 120 V ac, 50/60 Hz Power Connection.«;........................................................................................... 1

1.2 220/240 V ac, 50/60 Hz Power Connections....................................................................................... 1

2 INSTALLATION.................................................................................................................................... 1

2.1 Eack Mounting .................................................................................................................................. 1

2.2 Ventilation ............................................................................................................................ . 1

3 SIGNAL CONNECTIONS...................................................................................................................... 2

3.1 Input Connections ............................................................................................................................. 2

3.2 Line Output Connections.................................................................................................................... 2

3.3 Output Connections........................................................................................................................... 2

3.4 Output Cable Selection....................................................................................................................... 2

3.4.1 Calculating Power Los.ses with 8 ohm Loads

3.4.2 Calculating Power Losses with 4 ohm Loads................................................................................. 2

3.5 Damping Factor.......................................................................................................................... . 2

3.5.1 Calculating the Maximum Length of Cable for a Specified Damping Factor

3.C Speaker Protection Fuse Selection ...................................................................................................... 5

3.7 Compros.sion Driver Protection Capacitors ........................................................................................... 5

4 OCTAL ACCESSORY SOCKETS

5 PROTECTION SYSTEMS .............................................................................................................. . . 5

5.1 Load Protection Circuitry..................................................................................................................... 5

5.2 Amplifier Protection Circuitry ............................................................................................................... 5

5.3 Protect Indicator........................................................................................................................ . . 6

......................................................................... ...........................................................

..................................................................................

...............................

. 3

‘ 1

2

G OPERATION......................................................................................................................................... 6

G.l Dual Mode of Operation............................................................................................................... . . 6

G.2 Bridge Mode of Operation ................................................................................................................... 6

7 IN CASE OF PROBLEMS
8 SPECIFICATION

9 SERVICE INFORMATION.................................................................................................................. 10

9.1 Equipment Needed......................................................................................................................... 11

9.2 Adjusting SVRl and SVR2, the BIAS Trimpots

9.3 Ordering Replacement Parts ..............................

9.4 Factory Service

9.5 Technical Assistance .........................................

...................

................................................

6

7

11

11

11

11

ALTEC JJCStSING^ CORPORATION o a Mar-k W Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

1 ELECTRICAL

Two amplifier models are
available. One model has a 50/60
Hz power transformer with two
120 V ac primary windings. These
windings may be wired in parallel
or series for operation at either
120 V ac or 220/240 V ac. The
other amplifier model is for export
into countries where tlie ac line
voltage is 100 volts, 50/60 Hz. The
next two sections refer to the first
model witli the dual 120 V ac pri
mary windings.

1.1 120 V ac, 50/60 Hz

Power Coimections

'rhe amplifier is provided
with the primary of the power
transformer slrappcil for 120 V ac
operation from the factory. Refer
to Figure 2 for the wirijjg deUiils.

WARNING: Verify that the power

transformer’s priinaiy circuit con

figuration is correct for the in

tended ac line voltage BEFORE

applying power to the amplifier.

1.2 220/240 V ac, 50/60 Hz
Power Connections
The power transformer

has two 120 volt primary windings

which can be connected in parallel
for 120 V ac line voltages, or in
series to meet 220/240 V ac re
quirements. Use the following
procetlures to re-strap the primary
of the power transformer for
220/240 V ac applications.

1. Malce sure the amplifier is

not connected to any
power source.

2. Remove and save the ten
screws securing the top

cover. Refer to Figure 1
for the exact screw loca
tions.

3. Locate terminal block TBl

located behind the AC

main power switch. Re
connect the leads as
shown in Figure 2.

4.

Install the top cover with
the ten screws previously
romovetl.

5.

Install the 2.0 A fuse,
T2.0A /250V slo-blo or
equivalent.

6.

Install the 230 Vac 50/-

60Hz and the T2.0A/250V
decals in the proper
positions.

INSTALLATION

2.1

Rack Mounting
The amplifier may be in

stalled in a standard 19 inch
equipment rack. It requires 1.75
inches of vortical rack space and
secures to the rack cabinet with

the-four rack mount screws and
cup washers provided in the hard
ware kit.

2.2 Ventilation
The amplifier m.;;;t be

adequately vontil.ntod tn ir.'oid ex
cessive temjjerature rise, i si;ould
not be used in areas where the
ambient temperature exceeds SO'C
(122°F). To determine i .imbi­ent air temperature, opemte the
system in the rack until the tem
perature stabilizes. Mea'"ro the
ambient air with a bulb-type ther
mometer held at the botloin of the
uppermost amplifier. Dc tmt let
the thermometer touch the netal
chassis because the chassis will be
hotter than the ambient a:.-. If the

air temperature exceerls 50°C
(122°F), the equipment siiould be
spaced at least 1.75 inches apart
or a blower installed to provide
sufficient air movement within
the cabinet.

WARNING: Do not operate the

amplifier within a completely
closed unventilated housing.

ALTEC LANSING* CORPORATION • a Mark IV Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

For example, suppose an installer
uses 160 feet of 10 GA 2-wire
cable with an 8 H speaker system.

WHITE (A.a HECEPTAia^

The total po%ver loss in .U. cable
is;

A. 120 V ac Primary Wiring

X I ^

WHITE (A.C RECEPTACLE)

BIACK BUWHT BLUE

BLACK BLIWirr BLUE

_______________

nV/HT BROWN

8.240 V ac Primary Wiring

BRIWHT BROWN

Figure 2 Primaiy Wiring Configuration for 120 V ac and 220/240 V ac

SIGNAL CONNEC
TIONS

3.1

Input Connection.s
Balanced input connec

tions may be made to either the

Va phono (TRS) or the female

XLR connectors. For single-ended

inputs, strap the low (—) input to

ment. Refer to Figure 3 for po.ssi-

ble 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

tj'pical output connections.

ground (pin 3 on XLR or Ring on

Va" phone). Otherwise, the elect

ronically-balanced input stage will
see 6 dB loss input signal level
than with a balanced input. Refer
to Figure 3 for typical input con

nections.

3.4 Output Cable Selection
Speaker wire size plays an

important part in quality sound
systems. Small wire gauges can
waste power and reduce the
damjiing factor at the speaker
terminals. This can add coloration

3.2 Line Output Connec
tions
TliD XLR and Vi" phone

connectors are wired in parallel.

Pin 2 of the XLR is the Tip of the

and muddincss to the sound. To
help offset this problem. Table I
has been assembled to enable you
to calculate the power losses in
the speaker cable.

Va" phono comiector, and pin 3 is

the Ring. Since the input imped

ance of the electronically-balanced

input stage is high (15 kohms),

there is minimal loading on the
signal source, Wien the input
connections are made to one con

nector, the other may be used as
an auxiliary line output to feed
other high input impedance equip

3.4.1 Calculating Power
Losses with 8 ohm
Loads
To calculate the total

power loss in the spealcer cable,
multiply the power loss per foot
(or meter) of the 2-wire cable sel
ected from Table 1 by the length
of the cable in feet (or meters).

Total Power Loss in cable

= 0.0191 watts/foot X lOr feet

= 3.0 watts

Does this mean that whena er the
amplifier produces 75 walls of
output power, 72.0 watts (75 watts
minus 3.0 watts) will be delivered
to the 8 ohm load? N'^d The

actual load impedance is ohms

plus the resistance of Iht cable

(0.00204 ohms/foot times L'"' feet)
for a total load imped.nice of

8.3264 ohms. At the 8 lated
output power, the output, /oltage

is 24.4 V rms. Therefore, I t ■ amp
lifier produces 71.5 wati - with
this load instead of 75 wa.‘ . This

was calculated by squaring the
voltage and dividing by I load

impedance (24.4* divid. i by

8.3264 ohms). As a result, ue act
ual power delivered to thf !-ad is

68.5 watts (71.5 watts minus 3.0

watts).

Had 18 GA wire been used hi the
above example, the lass in the
cable would have been Ifl.r ivatts.

Tliis example lllustrale.s I im
portance of using the pro; . wire
size.

3.4.2 Calculating <wer
Losses with 4 ohm
Loads
To calculate the- i sses

when using a 4 ohm speak .-; os
tein, multiply the loss at hms
by 3. In the above exampk-. the 10
GA wire would consume 9,'' watts
of power while the 18 GA '.■.•ire
would waste 58.5 watts more

than half of the amplifier’’^ ohm

power rating.

3.5 Damping Factor
The higher the da aping

factor rating of an amplill'-!' the
greater the ability of the am; lifier

A1.TEC lANSING' CORPORATION * a Mark T\' Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

inward but its niomontum cmises
it to overshoot its resting point.

SOURCE AMPLIFIER'S INPUTS

BALANCED

SOURCE

BALANCH3

SOURCE

H/600 OHM

TERMINATION

UNBALANCED

SOURCE

------------

UNBALANCED

SOURCE

/, 1

LO (-)

HOT

HOT

J COM

'G j

r

NC

Figure 3 Topical Input Connections

SINGLE-ENDEO AUX OUTPUT

XLn BAFIflIEH STRIP

2 (+)

3 (-)

6Ю ¡-

7lr ^

ЯЛ

ВАИЙ1ЕП STHIP

2

Э

—t i

(t)

H

E.ND ,

%

Ж.

-----

AUX OUTPUTS

(USER OPTIONS)

BAL
OUTPUT

HOT

KEEP

COM

CABLE
RUNS
UNDER

6 ft

HOT

OR 2 m

COM

NC

This overshoot will dampen itself
out eventually but the unwanted
movements can add consitlerable

distortion products to tlu touiul.

In the process of moving hv.vard
through the magnetic fieUh the
voice coil assembly generatos a
current of opposite polarity tn the
original signal. This current in
duces a voltage or "back EMF”
which travels through the speaker
wire to the amplifier's '.utput.
The lower the amplifier’i. output
impedance, the faster tl.o over­slioot of the voice coil will dampen
out. The output impedii'io; of an
amplifier can be calculated by
dividing the rated output linped-

ancG, typically 8 ohms, uy the
damping factor. The 944 i A has a
damping factor rating ; 100
which corresponds to an 4Utput
impedance of 0.08 ohni.s.

AMPLIFIER'S OUTPUTS

SPEAKER OUTPUTS

CH 1 L‘

eniOGE OUTPUT Q I I

CH г
BRIDGE MODE

Figure 4 'Topical Output Connections
to control unwanted speiiker cone

movements. When a signal drives
a woofer, current flowing through
the voice coil creates a magnetic
field. This field interacts with the

LOUDSPEAKER LOADS

HIGH POWER
FULL RANGE/

=0]

SUBWOOFER

permanent magnetic field in the
gap and forces tlie combination
cone and voice coil assembly to
move outward. When the signal is
removed, the assembly moves

3.5.1 Calculating the
Maximum Length of
Cable for a Spenified
Damping Factor Spec
ification at the Load
Tlie damping factor rating

is typically never realiz-т-: at the
load because of the rosisLunce of
the cable (and other facLnia such

as the contact resistance of an
output relay or the resistance of
an output fuse). Tlie damping fac
tor at the load should be 30 for
general paging systems ami 50 for
high fidelity music systcm.s. Econ
omics usually dictate, however,
that these numbers are cut-in
half. The resulting dampiiig factor
at the load should be based on ex
perience and customer satis
faction. Once a minimum; c ciiiping
factor is determined for => partic

ular type of installation, the fol

lowing equation can calculate the

maximum length of 2-wire cable
which can be used to achieve the
minimum damping factor .s^x cified
at the load:

ALTEC LANSING* CORPORATION • a Mark TV Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

Max. Length of 2-wire cable in
feet

ZL — Zo

= DF

DCR/ft

where

ZL is thé load impedance
to comiect to the amp
lifier;
Zo is the amplifier’s out

put impedance (0.08 ohms

for the 944lA);
DF is the minimum per­mi.ssible damping factor at
tlie load; and
DCR/ft i.s the DC resis
tance of the 2-wire cable
per foot from Table I.

The same equation can be used to
calculate the maximum cable
length in meters by substituting
the DCR per meter value from
Table I.

Let’s use the equation. Suppose
ZL equals 8 ohms, Zo = 0.08
ohms, and the minimum damping
factor at tlic load is 25. In addi
tion, IS GA cable is preferred.
Then, the maxiinxim length of 18
GA cable which can be used to
achieve a damping factor of 25 fit

the load is;

8

25

(0.08)

IS.4 feet

0.01302 n/ft

Table I 9441A Power Losses in 2-wire Speaker Cable

Power

AWC, nc:n/fi I.ciss/n Socllonal UCR/iTicler I^ishKlcr

(0Л) (îVil) (willt.s/(1)

G 0.Ü0Û8I

8 0.00121 0.0i:)4 8.30 0.0042I 0.0394
10
12

И
IG
18 0.01302 0.1218 0.82
20 0.02070 0.1935
22

0.0020'!

0.00324

O.OO.'il.'i 0.0482

0.0081!)

0.03202 0.:t073

0.0075

0.0191

0.0303 3.31

0.0767

Figure 5 High-voltage Distribution System

Sometimes it may be necessarj' to
locate the speaker 100 feet or
more away from the amplifier. In
this situation, a much larger
gauge cable is required. However,
this may not be jiractical or eco
nomical. The size of the 2-wire
cable can be greatly reduced by
stepping up the output voltage of
tlie amplifier to 70, 100, 140, or
210 volt, using an output trans
former, then stepping down the
voltage at the load. Such a system
is shown in Figure 5.

Cable Cross­area (iiim*) (U/m)

13.30 0.00204

5.26 0.00669

2.08 0.01691
I.3I 0.02085 0.2508

0.52

0.33 0.10658

0.01063 0.0052

0.042S9 0.39Î16

0.06764 0.6288

Power
(woUs,/m)

0.0247

0.0626

0.1581

0.9860

I'he maximum
cable in this situation can be
approximated from the following
equation:

Max. Length of 2-wire o;

feet

(Pout)(DCR./ft)

where

V is the stejipod-up
voltage of the system;
Pout is the rated output
power of the amidifier;
Zo is the output imfied­ance of the amplifier (0.08
ohms for the 9441A r,
ZL is the load impeo.mce;
DCR/ft is tb. DC

resistance of th: 2-wire

cable per foot from Table

I; and
DF is the minimum
permissible damping fac

tor at the load.

length of v-v/ire

ie in

Zo

J_

ZJ.

DF

ALTEC LANSING* CORPORATION © a Mark IV Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

Suppose a 210 volt system were
used at a 200 watt power level to
drive an 8 ohm load with a mini
mum damping factor of 25. Using
the same 18 GA cable as before,
the maximum length can now be
508 feet. Power companies use
this technique to transfer large
amounts of power over great dis
tances.

3.6 Speaker Protection
Fuse Selection
Sometimes it may be de

sirable to use in-line fuses (fuses
in series with the output) to pro
tect loud-sixjakor s3 'stems (or the
ampIirieiO- It is difficult, however,
todotermino the proper fuse value
with the correct lime lag and
overload cliaracteristics to match
the limitations of a speaker sj’s­tem. The values shown in Table II
should serve only as a guide. To
use, determine the power rating
and load value. Then, select a
standard value fuse of the next
smaller value to the one listed in
tlie table.
The values are calculated for fast­blow fuses which carry 135% of
their current rating for an liour
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 nnni­mize deterioration of the damping
factor at the load. Refer to the
example in Figure 4.

Table II Calculated Output Fuse
Values

Power 1 a 8П ion

(4Villl.s)

100 3.70 2.02 1.85

l-TO 3.21 2.27

200 5.2-1 3.70 2.02

3(X1 0.-12

400 7.-11
000

bond

0.07

LoafI

■-1..5-1 3.21

5.2-1

0.42

l.o.-)(l

3.70

4.5-1

3.7 Compression Driver
Protection Capacitors
Compression drivers, u.sed

for mid to high frequency sound
reproduction, are much more sus
ceptible lo damage from low' fre
quencies than large cone loud
speakers. Even though an elec
tronic crossover may be cmploj’od,
problems may arise in the cables
between the cros.sover and the
power amplifier, or from mis­adjustment of the cros.sover.
Either of those situations could
apply low frequency signals or
hum to the driver and cause
damage. To prevent a potential
mishap, Altec Lansing recom
mends using a capacitor between
the amplifier and the compression
driver to suppre.ss low frequencies
and possible DC. Refer to the
example in Figure 4.
In choosing a value, one must be
careful not lo interfere with the
crossover frequency. As a general

rule, select a capacitor whose
break frequency, with respect to the
load, is 3 dB down at approxi
mately Vu of the high pass comer

frequency.

Table III Compression

Driver

Protection Capacitors

Crossover 3 fl ion

Frequency Driver Driver

500 llz 80 |iF 40 iiF

800 llz 50 цР 25 iiF
1000 Hz 40 III­1250 Hz
2000 Hz
3150 Hz 12 tiK

33 >iF 10 pF
20 tiF 10 |aF

20 tiF

6 (iF

Mylar capacitors with ai !st a

100 volt ac rating are -om-

mended. Table III show.: ;e re
commended capacitor val ;; for
use with 8 and 16 olnn dr’ ', rs at
popular crossover frequoucie.';.

4 OCTAL ACCES ORY

SOCKETS

Two octal sockets ¡i' ^rnita
variety of plug-in accessc.rii’n to be
used w'ith the amplifier. Uoi ...ally,
one “U" jumper is ins(-r'- be

tween octal socket pins : ,;d 1,

and another between pins " nid 6.

These jumpers must re;;:. ■; in.

place for the amplifier to .'rate

when not using any . : sorj
modules. To use with an ac .soiy

module, remove (and sr.- -- the

jumpers and install the . ulule

making sure the key on it ■ ■ .'nter
post aligns with the groove- ’ . the
female socket. For operation, refer
to the instructions provide d with
the modulo. Schematically the
module will be inserted '■ r.ween

the input connector and - bal
anced input stage.

Electronic modules are ; ... red
from a bipolar 15 volt su ily in

the amplifier. The sxij-: : is
capable of supplying up to 25 ma
DC of current. Currents ¡¡. i:;;icess
of 25 ma DC may prevent Li; ■ amp
lifier from disengaging :n its
built-in protection mecha:;’ .as.

5 PROTECTION SYS

TEMS

5.1 Load P rote: ’on

Circuiti'y
Each channel ind yend-

ently protects its load from

startup/shutdown transir>n'-DC,
and large subsonic signals.

5.2 Amplifier Protc-otion

Cii'cuitry
A unique current-lL.dling

circuit was designed specifically

for the amplifier. It feat .es a
variable current limit whic! is a

ALTEC LANSING^ CORPORATION * a Mark TV Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

function of the output signal vol
tage. As a result, the amplifier can
deliver the rated currents into
rated loads but substantially
limits the current into low imped
ance or shorted loads (shorted
output terminals). Once the short
is removed, however, the amplifier
will resume normal operation.

The heatsink is conventionally
cooled. Slioxild the heatsink
temperature of a channel remain
excessively high, both chamiels
will .shut down automatically.

Wien the output devices cool to a

safe operating temperature, the
channels will automatically re
sume normal operation.

5.3 Protect Indicator
I'he “PROTECT” LED

illuminates when either channel
enters thermal protection. If a
shutdown does occur, the chan

nels will resume normal operation
as soon as its devices have cooled
to an acceptable temperature.

If the protection LED illuminates
and there is no indication of ex
cessive temperature, one, or both,
of the channels is in an internal

fault mode. If this occurs, refer to

the service instructions on page

12.

G OPERATION
G.l Dual Mode of

Operation
In the dual mode of opera

tion, the channels may be
operated independently. After in
stallation and hookup, verify that

the mode switch, located on the
rear panel, is in the “DUAL” posi
tion and rotate the level controls
fully counterclockwise (full atten
uation). Input a 0 dBu (0.775 V
rms) nominal signal level and
apply power. Slowly increase the
level controls until the desired
output power is obtained. If either

“CLIP” LED illuminates, reduce
the outjnit with the channel level

control or reduce the input signal

level at its source.

WARNING: Never attempt to con

nect the outputs of the two chan
nels in parallel.

6.2 Bridge Mode of
Operation

After installation and
hookup, verify that the mode
switch, located on the rear panel,
is in the “BRIDGE” position.
Rotate both levels controls fully
counterclockwise (full attenua

tion). Input a 0 dBu (0.775 V rms)

nominal signal level into channel

1 only and apply power. Slowly in

crease the level control of channel

1 until the desired output power

is obtained. If either “CLIP” LED

illuminates, reduce the output
level with the level control or re
duce the input signal level at its
soiirce.

CAUTION: Be sure that no input

connections are made to channel 2
and that its level control is fully
counterclockwise (OFF).

WARNING: The bridged output

mode provides a true halariced-to-

ground output. Do not use any test

equipment to test or evaluate tins
amplifier which does not have

floating grounds.

In Case of Problems
Please check the following

items:

1.

Verify that tlie amplifier

is properly coimected to
an ac power source and
that the source is active.

2.

Verify that the input
connections are properly
made. Refer to Figure 3.

3.

Verify that the output
comiections 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. Ensure that the two

jumpers for each octal

socket are properly in
stalled (if not using op
tional plug-in modides).

7. Ensure that any aece.ssory
modules installed do not

draw more than i'u ma
DC of current.

8. Check that the mode

switch is in tin; •' :ured
position.

NOTICE: Repairs performed, by

other than authorized wananiy
stations (Dealers) or q: 'ified

personnel shall void the ivm—anty

period of this unit. To avoid loss

of warranty, see your neare;-; Altec
Lansing authorized dealer, or call

Altec Lansing Customer e-ervice

directly at (405) 324-531' Fc\X

[phone], or write:

Altcc Lansing Customei

Sciwice/Repair
10500 W. Reno
Oklahoma City, OK 73128

U.S.A.

AIAEC LANSING^ CORPORATION o o Mark T\^ Company

operating and Service Instructions for the Altec Lansing 944lA Power Amplifier

8

Conditions:

1. 0 dBu = 0.775 volts rins.

2. Dual mode ratings are for each channel.

3. Both channels operating at rated output power

4. 120 volt ac line input voltage maintained for all

Continuous Rated Output Power:

(20 IIz - 20 kHz at less than 0.1% THD)
Dual mode, 4 fi; 100 watts/ch
Bridge mode, 8 fl: 200 watts
Dual mode, 8 fl; 75 watt..s/ch
Bridge mode, 16 Cl: 150 watts

Continuous Rated Output Pow'er to Subwoofer:

(20 llz - 1 kHz at less than 0.1% TIID)
Dual mode, 4 0: 130 watts/ch
Bridge mode, 8 O: 260 watts
Dual mode, 8 O: 95 watts/ch
Bridge mode, 16 O: 180 watts

Miiximum Midband Output Power:

(Ref. 1 kllz, 1% TIID, @120 volts ac line voltage)
Dual mode, 4 O:
Bridge mode, 8 O:
Dual mode, 8 O:
Bridge mode, 16 0:

(Ref. 1 kHz, 1% THD, @108 volts ac (10% sag))
Dual mode, 4 O:
Bridge mode, 8 O:
Dual mode, 8 O:
Bridge mode, 16 O:

SPECIFICATIONS

unless noted.
tests unless noted.

>145 watts/ch
>270 watts
>100 watts/ch
>200 watts

>115 watl.s/ch
>220 watts
> 80 watts/ch
>155 watts

Voltage Gain:

(Ref. 1 kHz)
Dual mode, 4 fl: 28 dB
Dual mode, 8 Cl: 30 dB
Bridge mode, 8 fl: 34 dB
Bridge mode, 16 fl: 36 dB

Input Sensitivity for Rated Output Powci-

(Ref. 1 kllz, ±0.5 dB)
Dual mode, 4 fl:
Bridge mode, 8 fl:
Dual mode, 8 fl:
Bridge mode, 16 ft:

Miiximum Input Level:

(Ref. 1 kHz)

Input Impedance:

(Ref. 1 kHz)
Balanced:
Unbalanced:

Polarity:

Phase Response:

(Any mode)
20 Hz:
20 kHz:

THD: <0.1% aVp. <0.05%)

(Any mode, 30 kHz measurement bandwidth i

OdBu (0.774 V - ' s)

-0.25 dBu (0.752 v rms)
+1.0 dBu (0.869 V .rms)
+ 1.0 dBu (0.869 ” rms)

+20 dBu (7.75 V . ms)

30 kfl
15 kfl

Positive-going signal

applied to pin 2 of TvLR
or (+) of */«" phone (tip)
produces positive-going
signal at (+) output

terminal.

<+25°

>—25°

(Ref. 1 kHz, 1% THD, @100 volts ac (17% sag))
Dual mode, 4 Cl:
Bridge mode, 8 fl;.
Dual mode, 8 fl:
Bridge mode, 16 fl:

Headroom (Before clip): >1 dB

(Ref. 1 kHz, 1% TIID, single channel mode)

Frequency Response: 10 Hz - 50 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)

> 95 watts/ch
>185 watts
> 70 watts/ch
>135 watts

ALTEC LANSING'^ CORPORATION » « Mark IV Company

IMD (SMPTE 4:1);

(Any mode)

Slew Rate:

Dual mode, 4 or 8 il:
Bridge mode, 8 or 16 fl:

Damping Factor:

(Dual mode, 8 fl)
1 kHz:

(Ref. 1 kHz, 0 dBr = rated output power into 8

ohms, single channel operating)

Noise; > 100 dB

(Below rated output power, A-weighting filter, 8 fl

dual mode, 50/60 Hz ac line frequency)

<0.1%

>19 V/psec

>37 V/psec

>100

<55 dBrCrosstalk:

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

Amplifier Protection;

Load Protection:

Cooling:

Hea(.sink:

Output Topology:

Output TVp®'

Dual mode:

Bridge mode:

Output Devices:

Total number:
Pdmax rating:
Vceo:

Ic:

Tjmax:

Controls and Switches:

Front:
Rear:

Front Panel Indicators:

Shorted output term
inals, Over-temperature,
RF interference

Startup/shutdown trans
ients, DC faults. Sub
sonic signals

Conventional heatsink
True complementary

symmetry

Unbalanced, each chan
nel
Balanced

4 devices
130 watts
180 volts DC
15 amps DC
150 “C

Two input level controls.
Power switch
Mode switch

Power LED, Clip LED (x

2), Protect LED

Operating ac Voltage

Range: Operates from line

voltages as low as 90
volts (at reduced output
power) assuminf; = 120 V
ac nominal line.

Power Consumption/

Heat Produced:
(Both channels operating in dual mode wit!- i kHz
sinewave input signal at slated output power into 4

Cl loads)

idle:

30 watts/0.102 kBTU/h

l/8lh max
midband power:

270 watts/0.833 kBTU/h

l/3rd max
midband power:

390 watts/1.099 kliTU/h

Rated output power: 600 walts/1.360 kBTU/h

Max midband power: 730 watts/1.490 kB'f'UAi

Opei'ating Temperature

Range;

Up to бО^С 122“F)
ambient

Dimensions (Rear of rack cars to max depth):

1.75 in II X 19 in W X

12.8 in D
(4.44 cm II X 48.26 cm W

X 32.51 cm D)

Connections;

Input:

Output:
Power:

Fuse Tjpe:

Power Requirements:

'// phone (x 2),
Female XLR (x 2),
Octal accessory socket (x

2), powered with ±15
volts DC at 25 ma.

Barrier strip
6 ft (1.83 m), 3-wire, 18

GA power cord with
NEMA 5-15 plug/IEC

T 4 A/250 V Slo-Blo or
equivalent (for 120 Vac
use)

120 Vac, 50/60HZ, 300
watts (configurable to
220/240 Vac). 100 Vac.
50/60 Hz model avail
able.

Shipping Weight:
Net Weight:
Color:
Enclosure;

Standard Accessories:

22 lbs (9.97 kg)
18 lbs (8.16 kg)
Black
Rack mount chassis, 16

GA steel, 3/16 i:; 5052
aluminum alloy front
panel

4 - “U” jumper idugs for
octal sockets '3 per
socket, installetl'

1 - Operating instruct

ions mid Service Manual

1 - 1'2 A/250 V ni.se (for

220/240 V ac '

ALTEC LANSING^ CORPORATION o a Mark TV Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

Optional Accessories:

1^9 )V

Power Limiter

put Bridging

mer
15515A Input Bridging
Transformer with Pad
15170 100 watt Auto
former
* 15581A 24 dB/oct
Li nkwitz-Riley Crossover
15594A-XXX 18 dB/oct
Low Pass Filters

15595A-XXX 18 dB/oct
High Pass Filters
15509A Bass Boost
module

The “-xxx” represents various corner frequencies
available for the corresponding filter.

* Note: Tlie 14712A, and the 15581A will

extend above and below the back panel

0.625 inches (1.58 cm).

ALTEC LANSING CORPORATION continually
strives to improve products and performance.
Tlierefore, the specifications are subject to ch.mge
witliout notice.

V

ALTEC LANSING* CORPORATION • a Mark IV Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

off

9441A Power Amplifier

SERVICE INSTRUCTIONS

* * * CAUTION * * *

NO USER SERVICEABLE PARTS INSIDE. EXTREMELY ILAZ­ARDOUS VOLTAGES AND CURRENTS MAY BE ENCOUNTERED
WITHIN THE CHASSIS. THE SERVICING INFORMATION CON

TAINED \VITHIN THIS DOCUMENT IS ONLY FOR USE BY ALTEC
LANSING AUTHORIZED WARRANTY REPAIR STATIONS AND

QUALIFIED SERVICE PERSONNEL. TO AVOID ELECTRIC

SHOCK, DO NOT PERFORM ANY SERVICING OTHER THAN THAT

CONTAINED IN THE OPERATING INSTRUCTIONS UNLESS YOU
ARE QUALIFIED TO DO SO. OTHERWISE, REFER ALL SER
VICING TO QUALIFIED SERVICE PERSONNEL.

10

ALTEC LANSING* CORPORATION o a Mark IV Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

9 SERVICE INFORM

ATION

WARNING; No user serviceable

parts inside. Extremely hazardous

voltages and currents may be en
countered within the chassis. The
servicing information contained
within this document is only for
use by Altec iMusing authorized
warranty repair stations and
qualiped service personnel. To
avoid electric shock DO NOT per

form any servicing other than that

contained in the Operating Instr
uctions unless you are qualified to
do so. Otherwise, refer all servi

cing to qualified senice personnel.

NOTICE: Modifications to Altec

Lansing products are not recom

mended. Such modifications shall

be at the sole expense of the

pcrson(s) or company responsible,

and any damage resulting there

from shall not be covered under

warranty or otherwise.

9.2 Equipment Needocl
To precisely adjust the

trimpots, you must have tlie fol
lowing equipment:

1 — Digital DC volt meter
2 — 4 Cl load rated at 200
watts
1 — Small non-conducting
flat-blade screwdriver or
set of plastic TV
alignment tools

Miscellaireous handtools

(to remove the top cover)

NOTE; If you need to verify the

amplifier's performance against
the rated specipcations, you must
be able to maintain the ac line
voltage constant at 120 V ac (or

240 V ac if wired according to

Figure 2). Therefore, we recom
mend a suitably rated variac (50
ampere rating at 120 V ac).

9.2 Adjusting VR02 and
VR102, the BIAS
Trimpot

To adjust VR02 and VR102 for
the proper bias, follow the pro
cedures below:

1. Turn power off and dis
connect the unit from its
power source. Make sure
the unit is in the Dual

mode with 4 D loads con
nected to each channel.

2. Remove the ten screws se
curing the top cover.
Refer to Figure 1 for the
.screw locations.

3. Channel 1: Locate the
junction of Ql2’s emitter

and R37. Connect the pos
itive side of the digital DC
volt meter to the junction
of QI2’s emitter and R37.
Then locate the junction
of Ql4’s emitter and R38.
Connect the negative side
of the digital DC volt
meter to the junction of
Ql4’s emitter and R38.
Connect the unit to its
power source and turn the
power on. Adjust VR02 so
that the digital DC volt
meter reads 7 milli volts
DC (± .2 mVdc). Turn
power off and disconnect
the unit from its power
source.

Note; Adjust Bias im

mediately after turning

power on.

4. Channel 2: Locate the
junction of Qll2’s emitter

and R137. Connect the

positive side of the digital

DC volt meter to the

junction of Q112’s emitter

and R137. Tlien locate
the junction of Qll4’s
emitter and R138.
Connect the negative side
of the digital DC volt
meter to the junction of
Qll4’s emitter and R138.
Connect the unit to its
power source and turn the

power on. Adjust VR102
so that the digiUiI DC volt

meter reads 7 milli volts

DC (± .2 mVdc). furn

power off and disc'.'iinect

the unit from its pow'er
source.
Note: Adjust r.ias im

mediately after Lii ruing
power on.

0

Re-install the lop cover

.

with the ten screws pre
viously removed.

9.7

Oi'ilex'ing Replacement
Parts
To order replacvinent

parts, look up the <r.lering
number from the componen, parts

listing and call (405) 32-5-531L,
FAX [phone], or wrih-:

Altec I.ansing
Replacement Parts Sales
P.O. Box 26105
Oldahoma City, OK 73120-0105

9.8 Factory Service
If factory ser\ ice is

required, ship the unit ;;i its
original packing prepaid tv

Altec Lansing Customer

Service/Repair
10500 W. Reno
Oklalioma City, OK 73128

Enclose a note describing the pro
blem in as much detail as possible.
Include any additional helpful in
formation such as test conditions,
where used, how used, etc,

9.9 Technical Assisi anee

For applications assistance

or other technical information,

contact the Technical Services

Manager. You can call (405) 324­5311, FAX [phone], or

write:
Altec Lansing

Technical Services Manager
P.O. Box 26105

Oklalioma City, OK 73126-0105

ALTEC LANSING'^ CORPORATION • a Mark IV Company

11

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

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Figure 6 Schematic of 9441A, Sheet 1 of 2

ALTEC LANSING* CORPORATION ® a Mark IV Company

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operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

__

Figure 7 Schematic of 9441A, Sheet 2 of 2

ALTEC LANSING* CORPORATION • a Mark IV Company

13

operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

Component Parts Listing for the 9441A

Reference Ordering
Designator Number

Name and Description

(

ROl, R02, RlOl, R102 47-03-121532
R03, R103 47-03-122803
R04-07, R104-107 47-03-028238
R08, R108 47-03-037660
R09, R109 47-01-028011
RIO, RllO, 47-01-028530
Rll, R25, Rll, R125 47-01-102072
R12, R44, R45, R47, R51, 47-01-102106
R112, R144, R145, R147, R151,
R203
R13, R113 47-03-028274
R14, R30, R114, R130 47-01-102112
R15, R18, R115. R118 47-01-102080
R16, R19, R116, R119 47-01-102054
R17, R28, R32, R117, R128, 47-03-038030
R132
R20, R33, R120, R133 47-03-028694
R21, R121, 47-03-038031
R22, R122, 47-03-122953
R23, R123,— 47-03-038032
R24, R124 47-01-102085
R26 47-01-102111
R27, R127, R202, R206, R207 47-01-102102
R29, R129 47-01-102110
R31, R131 47-01-102129
R34, R134 47-01-038033
R35, R36, R135, R136 47-01-038034
R37, R38, R137, R138 47-01-037992
R39, R43, R139, R143, 47-01-038035
R40, R140 47-01-038030
R41, R141 47-01-102098
R42, R142 47-01-102094
R46, R56, R146, R152 47-01-102119
R48, R58, R14S 47-01-102114
R49, R50-53, R59, R149, R150 47-01-102121
R54 47-01-107013
R55 47-01-102109
R57 47-01-102108
R63 47-01-038038
R126, R154 47-01-102082
R153, R201 47-01-102127
R204, R205 47-01-124444
R208, R208 47-01-102066
R210, R211 47-01-102046
R212, R213 47-01-113781
COI, C04, C19, GIOÌ, C104, 15-06-037215
C119
C02, C03, C102, C103 15-02-038039
C05, C105 15-01-038040

Resistor, 1.0 Kii, 0.25 watt, 1%, metal film
Resistor, 10 n, 0.25 watt, 1%, metal film
Resistor, 15.0 Kil, 0.25 watt, 1%, metal film
Resistor, 3.32 kil, 0.25 w'att, 1%, metal film
Resistor, 240 kfl, 0.25 watt, 5%, metal film
Resistor, 30 kfì, 0.25 watt, 5%, metal film
Resistor, 560 fl, 0.25 watt, 5%, metal film
Resistor, 15 Kfl, 0.25 watt, 5%, metal film

Resistor. 39.2 Kfl, 0.25 watt, 17c, metal film
Re.sistor, 27 Kfl, 0.25 watt, 5%, metal film
Resistor, 1.2 Kfl, 0.25 watt, 5%, metal film
Resistor, 100 fl 0.25 watt, 5%, metal film
Resistor, 91 fl, 0.25 watt, 1%, metal film

Resistor, 150 Í1, 0.25 watt, 1%, metal film
Resistor, 47 Kfl, 0.25 watt, 1%, metal film
Resistor, 22.1 Kfl, 0.25 watt, 1%, metal film
Resistor, 820 fl, 0.25 watt, 1%, metal film
Resistor, 2 Kfl, 0.25 watt, 5%, meUd film
Resistor, 24 kfl, 0.25 watt, 5%, metal film
Resistor, 10 Kfl, 0.25 watt, 5%, metal film
Resistor, 22 kfl, 0.25 watt,
Resistor, 120 Kfl, 0.25 watt, 57c, metal film
Resistor, 300 fl, 2 watt, 5%, metal oxide
Resistor, 68 fl, 2 watt, 5%, metal oxide
Resistor, 0.330 fl, 5 watt, 5%, cement
Resistor, 10 fl, 2 watt, 5%, metal oxide
Resistor, 80 Kfl, 0.25 watt, 57c, metal film
Resistor, 6.8 Kfl, 0.25 watt, 57c, metal film
Resistor, 4.7 Kfl, 0.25watt, 5%, metal film
Resistor, 47 Iffl, 0.25 watt, 5%, metal film
Resistor, 33 KD, 0.25 watt, 5%, metal film
Resistor, 56 Kfl, 0.25 watt, 5%, metal film
Resistor, 220 Kfl, 0.25 watt, 50c, metal film
Resistor, 20 Kfl, 0.25 watt, 5%, metal film
Resistor, IS Iffl, 0.25 watt, 57c, metal film
Resistor, 1.5 Kfl, 0.25 watt, 57c, metal oxide
Resistor, 1.5 Kfl, 0.25 watt, 5%, metal film
Resistor, 100 Kfl, 0.25 watt, 5%, metal film
Resistor, 4.7 Kfl, 2 watt, 5%, metal oxide
Resistor, 330 fl, 0.25 w'att, 5%, metal film
Resistor, 47 fl, 0.25 watt, 57c, metal film
Resistor, 330 fl, 2 watt, 5%, metal oxide
Capacitor, 0.1 pF, 100 volt, 5%, mylar

Capacitor, 100 pF, 100 volt, 57c ceramic
Capacitor, 0.1 pF, 50 VDC. electrolytic

5%, metal film

14

ALTEC LANSING^ CORPORATION ® a Mark W Company

operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

Reference Ordering
Designator Number

Name and Description

C06, C106 15-06-038041
C07, C17, C18, C107, C117, 15-06-038042

Capacitor, 680 pF, 100 volt, 5%, polypropylene
Capacitor, 200 pF, 100 volt, 5%, polypx-opylene

C118
C08, C09, C108. C109 15-02-038043
CIO, C13, Clio, C113 15-01-038002

Cll, cm 15-01-038044

C12, Cl 12 15-02-038006
C14, Cl5, C21, Cl 14, C115, 15-01-037907

Capacitor, 10 pF, 200 volt, 5%, ceramic
Capacitor, 47 pF, 63 VDC, electrolytic
Capacitor, 22 pF, 25 VDC, electrolytic (B.P.)
Capacitor, 30 pF, 200 volt, 6%, ceramic
Capacitor, 4.7 pF, 50 VDC, electrolytic

C121
C16, C116 15-01-038045
C20 C22, C120, C122 15-01-038046
C23, C24, C123, C124 15-01-038047
C25, C125 15-01-038048
C26 15-01-038049
C27, C28 15-01-038050
C201, C202 15-01-038005
C203, C204 15-01-038001

C205, C206 15-01-038000
C207 15-01-038051
LOl, LlOl 56-01-038052
DOl, D05, D06, DlOl, D105, 48-01-038053

Capacitor, 4.7 pF, 50 VDC, electrolytic (B.P.)
Capacitor, 100 pF, 100 VDC, electrolytic
Capacitor, 0.22 pF, 100 VDC, electrolytic
Capacitor, .47 pF, 50 VDC, electrolytic
Capacitor, 22 pF, 50 VDC, electrolytic
Capacitor, 47 pF, 50 VDC, electrolytic
Capacitor, 1000 pF, 63 VDC, electrolytic
Capacitor, 47 pF, 16 VDC, electrolytic
Capacitor, 22 pF, 16 VDC, electrolytic
Capacitor, 1 pF, 50 VDC, electrolytic
Inductor, 0.7 pF, coil
Diode, 1S155, switching

D106
D02, D04, D102, D104, D107,

48-02-042787 Diode, 1N4004, rectifier
D202, D203
D03, D103
D201
D204, D205
TCOl, ICIOI
IC02
QOl-03, Q17, QlOl-103, Q117

Q04, Q05, Q08, Q16, Q104,

48-01-122601

48-02-037985

48-01-037984

17-01-124804

48-03-026634

48-03-124824

Diode, 1N4148, switching
Diode, KBPC15-04, bridge
Zener Diode, 15 v(dt, 0.5 watt
1C, NJM 5532S ( ^. Г, рЛ
IC, ТЛ 7317P
Transistor, 2SA 970 GR, PNP

Transistor, 2SC 2240 GR, NPN
Q105, Q108, Q116, Q118
Q06, Q09, Q106, Q109 48-03-038054
Q07, QlO, Q107, QUO 48-03-037237

Qll, Qlll 48-03-038055
Q12, Q112 48-03-038056
Q03, Q04, Q103, Q104 48-03-026634
Q13, Q113 48-03-038057
Q14, Q114 48-03-038058
Q15, Q115 48-03-037983
Q201 48-03-124822
Q202 48-03-037236

53-02-038017

TSl, TS2 53-01-038061

56-08-038059
FI 51-04-038060
SWl 51-02-038066

у

SW2 53-01-038061

VROl, VRIOI 47-01-038063

Transistor, 2SC 2235 Y, NPN
Transistor, 2SA 965 Y, PNP
Transistor, 2SC 4381 Y, NPN
Transistor, 2SC 3519 Y, NPN
Transistor, 2SA 970 GR, PNP
Transistor, 2SA 1667 Y, PNP
Transistor, 2SA 1386 Y, PNP
Transistor, 2SC 2229 Y, NPN
Transistor, KTC 223SA Y, NPN
Transistor, KTA 968 Y, PNP
Thermister, NTC B57364-S209-M
Thermal switch, 115N
Transformer, 9441A (UB)
Fuse, T4 amp, 250 volt, SB-UL-GLS
Switch, power, H 8650 VB (250V lOA)
Switch, bridge, SS22F22-G9
Potentiometer, volume, 18PN01 C41 15SKA5K

ALTEC LANSING^ CORPORATION • a Mark IV Company

15

operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

Reference
Designator

VR02, VR102
LED 01, 101, 102, 201

Ordering
Number

47- 06-038064
45-01-038065
48- 04-038018
21-03-038019
28-13-026422

Neime and Description
Potentiometer, bias, 422Z BlK

Relay, AW 8812
L.E.D., KLR-124 3 mm
Dual Binding Post, TB-301D RED/Black
Hardware, rack mount

21-01-013567 Jumper, Octal Socket, gold flash

r
l

16

ALTEC LANSING* CORPORATION o o Mark IV Company

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifiei

ADDENDUM

TO THE ALTEC LANSING 9441A

OPERATING AND SERVICE INSTRUCTIONS

The following is a change to the Electrical Instructions of the Altec Lansing 944lA Power Amplifier found on pages

1 and 2 of the Operating and Service Instructions (Part Number 42-02-037980).

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 line

voltages, or in series to meet 220/240 V ac requirements. Use the following procedures to re-strap the i-i-imary of
the power transformer for 220/240 V ac applications.

1. Make sure the amplifier is not connected to any power source.

2. Remove and save the ten screws securing the top cover. Refer to Figure 1 for the exact screw locations.

3. Locate terminal block TBl located behind the AC main power switch. Reconnect the leads as showr- in Figure

2.

4. Install the top cover with the ton screws previously removed.

5. Install the 2.0A fuse, T2.0A /250V slo-blo or equivalent.

6. Install the 230 Vac 50/60Hz and the '1'2.0A/250V decals in the proper positions.

Figure 2 Primary wiring Configuration for 120 V ac and 220 V uc

Printed in U.S.A. 7/92

Revision 1 42-02-038412

operating and Service Instructions for the Altec Lansing 9441A Power Amplifier

P.O. Box 26105 * Oklahoma City, OK • 73120-0105 • USA * Tol; [phone] • FAX; (405] 324-8961

Printed in U.S.A. 04/92

a Maik IV 05tn|)an/

© 1992 by Altee Lansing Corporation. Ail liglils reserved worldwide.

42-02-037980