Crown D Series User manual

Operation Manual
D-45
Obtaining Other Language Versions: To obtain information in another language about the use of this product, please contact your
local Crown Distributor. If you need assistance locating your local distributor, please contact Crown at 574-294-8000.
This manual does not include all of the details of design, production, or variations of the equipment. Nor does it cover every possible
situation which may arise during installation, operation or maintenance.
The information provided in this manual was deemed accurate as of the publication date. However, updates to this information may have
occurred. To obtain the latest version of this manual, please visit the Crown website at www.crownaudio.com.
Trademark Notice: Crown, Crown Audio, Amcron and IOC are registered trademarks of Crown International. Other trademarks are the
property of their respective owners.
Some models may be exported under the name Amcron.®
©2007 by Crown Audio®Inc., 1718 W. Mishawaka Rd., Elkhart, Indiana 46517-9439 U.S.A. Telephone: [phone] 125243-10
10/07
D Series
D-75A
SIGNAL
IOC
CHANNEL 1 CHANNEL 2
HEADPHONES POWER
OFF ON
LEVEL
30
50
40
0
10
20
LEVEL
30
50
40
0
10
20

Operation Manual
D Series Power Amplifiers
page 2
1) Read these instructions.
2) Keep these instructions.
3) Heed all warnings.
4) Follow all instructions.
5) Do not use this apparatus near water.
6) Clean only with a dry cloth.
7) Do not block any ventilation openings. Install in accor-
dance with the manufacturer’s instructions.
8) Do not install near any heat sources such as radiators,
heat registers, stoves, or other apparatus (including
amplifiers) that produce heat.
9) Do not defeat the safety purpose of the polarized or
grounding-type plug. A polarized plug has two blades
with one wider than the other. A grounding-type plug has
two blades and a third grounding prong. The wide blade
or the third prong is provided for your safety. If the pro-
vided plug does not fit into your outlet, consult an electri-
cian for replacement of the obsolete outlet.
10) Protect the power cord from being walked on or pinched,
particularly at plugs, convenience receptacles, and the
point where they exit from the apparatus.
11) Only use attachments/accessories specified by the manu-
facturer.
12) Use only with a cart, stand, tripod, bracket, or table speci-
fied by the manufacturer, or sold with the apparatus.
When a cart is used, use caution when moving the cart/
apparatus combination to avoid injury from tip-over.
13) Unplug this apparatus during lightning storms or when
unused for long periods of time.
14) Refer all servicing to qualified service personnel. Servic-
ing is required when the apparatus has been damaged in
any way, such as power-supply cord or plug is damaged,
liquid has been spilled or objects have fallen into the
apparatus, the apparatus has been exposed to rain or
moisture, does not operate normally, or has been
dropped.
15) WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK, DO NOT EXPOSE THIS APPARATUS TO RAIN
OR MOISTURE.
16) DO NOT EXPOSE TO DRIPPING OR SPLASHING. DO
NOT PLACE OBJECTS FILLED WITH LIQUID, SUCH AS
VASES, ON THIS APPARATUS.
TO COMPLETELY DISCONNECT THIS EQUIPMENT FROM
THE AC MAINS, DISCONNECT THE POWER SUPPLY CORD
PLUG FROM THE AC RECEPTACLE. THE MAINS PLUG OF
THE POWER SUPPLY CORD SHALL REMAIN READILY
OPERABLE.
POUR DÉMONTER COMPLÈTEMENT L'ÉQUIPEMENT DE
L'ALIMENTATION GÉNÉRALE, DÉMONTER LE CÂBLE D'ALI-
MENTATION DE SON RÉCEPTACLE. LA PRISE D'ALIMEN-
TATION RESTERA AISÉMENT FONCTIONNELLE.
PARA DESCONECTAR COMPLETAMENTE EL EQUIPO DEL
SUMINSTRO ELECTRICO, DESCONECTE EL CABLE DE ALI-
MENTACION DE LA TOMA DE CA. LAS PATAS DEL CONEC-
TOR DEL CABLE DE ALIMENTACIÓN DEBERAN
MANTENERSE EN BUEN ESTADO.
TO PREVENT ELECTRIC SHOCK DO NOT REMOVE TOP OR
BOTTOM COVERS. NO USER SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
À PRÉVENIR LE CHOC ÉLECTRIQUE N’ENLEVEZ PAS LES
COUVERCLES. IL N’Y A PAS DES PARTIES SERVICEABLE À
L’INTÉRIEUR. TOUS REPARATIONS DOIT ETRE FAIRE PAR
PERSONNEL QUALIFIÉ SEULMENT.
PARA PREVENIR UN CHOQUE ELÉCTRICO, NO RETIRE LAS
CUBIERTAS SUPERIOR O INFERIOR. NO EXISTEN PARTES
QUE PUEDAN SER REPARADAS POR EL USUARIO AL INTE-
RIOR. REMITA EL SERVICICO AL PERSONAL TÉCHNICAL
CALIFICADO.
WATCH FOR THESE SYMBOLS:
The lightning bolt triangle is used to alert the user to the risk
of electric shock.
The exclamation point triangle is used to alert the user to
important operating or maintenance instructions.
REGARDEZ CES SYMBOLES
La triangle avec le sigle ‘’foudre’’ est employée pour alerter
l'utilisateur au risque de décharge électrique. Le triangle avec
un point d'exclamation est employée pour alerter l'utilisateur
d’instruction importantes pour lors opérations de mainte-
nance.
ATENCION CON ESTOS SÍMBOLOS
El triángulo con el símbolo de rayo eléctrico es usado para
alertar al usuario de el riesgo de un choque eléctrico.
El triángulo con el signo de admiración es usado para alertar
al usuario de instrucciones importantes de operación o man-
tenimiento.
Important Safety Instructions
FCC COMPLIANCE NOTICE
This device complies with part 15 of the FCC rules. Operation is subject to the following
two conditions: (1) This device may not cause harmful interference, and (2) this device
must accept any interference received, including interference that may cause undesired
operation.
CAUTION: Changes or modifications not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
NOTE: This equipment has been tested and found to comply with the limits for a Class B
digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This
equipment generates, uses, and can radiate radio frequency energy and, if not installed
and used in accordance with the instruction manual, may cause harmful interference to
radio communications. However, there is no guaranteethat interferencewill not occur in a
particular installation. If this equipment does cause harmful interference to radio or televi-
sion reception, which can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the
receiver is connected.
• Consult the dealer or an experienced radio/TV technician for help.
IMPORTANT
D Series amplifiers require Class 2 output wiring.
Les amplificateurs de série de D exigent des câbles de sortie de
classe 2.
D-Reihe-Verstärker verlangen Klasse die 2 Produktionsverdrah-
tung.
Los amplificadores de la Serie D requieren de un cableado de salida
Clase 2.
MAGNETIC FIELD
CAUTION! Do not locate sensitive high-gain equipment such as
preamplifiers or tape decks directly above or below the unit.
Because this amplifier has a high power density, it has a strong
magnetic field which can induce hum into unshielded devices that
are located nearby. The field is strongest just above and below the
unit.
If an equipment rack is used, we recommend locating the ampli-
fier(s) in the bottom of the rack and the preamplifier or other sensi-
tive equipment at the top.

page 3
D Series Power Amplifiers
Operation Manual DUE TO LINE CURRENT HARMONICS, WE RECOMMEND THAT YOU CONTACT YOUR SUPPLY AUTHORITY BEFORE CONNECTION.
DECLARATION of CONFORMITY
Crown International, Inc.
Sue Whitfield
574-294-8289
[email protected]
European Representative's Name and Address:
Nick Owen
35, Bassets Field
Thornhill
Cardiff. South Glamorgen
CF14 9UG United Kingdom
Equipment Type: Commercial Audio Power Amplifiers
Family Name: D Family
Model Names: D-45, D-75A
EMC Standards:
EN 55103-1:1997 Electromagnetic Compatibility - Product Family Standard for Audio, Video, Audio-Visual and Entertainment Lighting Control Apparatus for Professional Use, Part 1: Emissions
EN 55103-1:1997 Magnetic Field Emissions-Annex A @ 10 cm and 20 cm
EN 61000-3-2:2001 Limits for Harmonic Current Emissions (equipment input current less than or equal to 16 A per phase)
EN 61000-3-3:2002 Limitation of Voltage Fluctuations and Flicker in Low-Voltage Supply Systems Rated Current less than or equal to16A
EN 55022:2003 Limits and Methods of Measurement of Radio Disturbance Characteristics of ITE: Radiated, Class B Limits; Conducted, Class A
EN 55103-2:1997 Electromagnetic Compatibility - Product Family Standard for Audio, Video, Audio-Visual and Entertainment Lighting Control Apparatus for Professional Use, Part 2: Immunity
EN 61000-4-2:2001 Electrostatic Discharge Immunity (Environment E2-Criteria B, 4k V Contact, 8k V Air Discharge)
EN 61000-4-3:2001 Radiated, Radio-Frequency, Electromagnetic Immunity (Environment E2, criteria A)
EN 61000-4-4:2001 Electrical Fast Transient/Burst Immunity (Criteria B)
EN 61000-4-5:2001 Surge Immunity (Criteria B)
EN 61000-4-6:2003 Immunity to Conducted Disturbances Induced by Radio-Frequency Fields (Criteria A)
EN 61000-4-11:2001 Voltage Dips, Short Interruptions and Voltage Variation
Safety Standard:
IEC 60065: 2001 7th Ed. Safety Requirements - Audio Video and Similar Electronic Apparatus
I certify that the product identified above conforms to the requirements of the EMC Council Directive 89/336/EEC as amended by 92/31/EEC, and the Low Voltage Directive 73/23/EES as amended by 93/68/EEC.
Larry Coburn
Signed
Title: Senior Vice President of Manufacturing
Date of Issue: Jan. 1, 2006
Issued By: Crown International, Inc.
1718 W. Mishawaka Road
Elkhart, Indiana 46517 U.S.A.
COMPLIANCE QUESTIONS ONLY:

Operation Manual
D Series Power Amplifiers
page 4
Important Safety Instructions .......................................................2
Declaration of Conformity ............................................................3
1 Welcome ..................................................... 5
1.1 Features ...........................................................................5
1.2 How to Use This Manual ..................................................5
2 Setup ......................................................... 6
2.1 Unpack Your Amplifier......................................................6
2.2 Install Your Amplifier .......................................................6
2.3 Ensure Proper Cooling ....................................................6
2.4 Choose Input Wire and Connectors .................................7
2.5 Choose Output Wire and Connectors ...............................7
2.6 Wire Your System ............................................................8
2.6.1 Dual Mode ..............................................................8
2.6.2 Bridge-Mono Mode ................................................8
2.7 Connect to AC Mains .......................................................9
2.7.1 AC Mains Voltage Configuration ............................9
2.8 Startup Procedure ............................................................9
3 Operation .................................................... 10
3.1 Precautions ......................................................................10
3.2 Controls, Indicators and Connectors ...............................11
3.3 Indicators .........................................................................12
3.4 Controls ..........................................................................12
3.5 Fuse Replacement ...........................................................12
4 Advanced Features and Options ......................... 13
4.1 Protection .......................................................................13
4.2 Options ...........................................................................13
4.2.1 Bridge-Mono Option ..............................................13
4.2.2 Input-Sensitivity Option ..........................................13
5 Troubleshooting ............................................ 14
6 Specifications .............................................. 15
7 Service ....................................................... 17
7.1 International and Canada Service ....................................17
7.2 US Service .......................................................................17
7.2.1 Service at a US Service Center ...............................17
7.2.2 Factory Service .......................................................17
7.2.3 Factory Service Shipping Instructions.....................17
7.2.4 Packing Instructions................................................17
7.2.5 Estimate Approval....................................................17
7.2.6 Payment of Non-Warranty Repairs...........................17
8 Warranty ..................................................... 18
Product Registration.....................................................................21
Crown Factory Service Information Form ....................................23
Table of Contents

page 5
D Series Power Amplifiers
Operation Manual
1 Welcome
Reliability is the first thing you get with your
purchase of a Crown®power amplifier. The D-
45 and D-75A both deliver dependable opera-
tion with a wide variety of loads. Because of
their exceptional reliability, these amplifiers
have become the leading choice of profession-
als for use in recording studios, laboratories
and public facilities. You can even find them on
the road. Their sonic excellence also makes
them a very good choice for your personal lis-
tening pleasure.
The D-45 and D-75A amplifiers are compact
and provide ultra-low distortion for medium
power applications. Crown’s advanced AB+B
circuitry ensures efficient operation and pro-
tects against shorted, open, mismatched or
low-impedance loads that can affect any ampli-
fier’s performance.
Modern power amplifiers are sophisticated
pieces of engineering capable of producing
extremely high power levels. They must be
treated with respect and correctly installed if
they are to provide the many years of reliable
service for which they were designed.
In addition, D Series amplifiers include a num-
ber of features which require some explanation
before they can be used to their maximum
advantage.
Please take the time to study this manual so
that you can obtain the best possible service
from your amplifier.
1.1 Features
Your dual-channel (stereo) amplifier can
optionally be configured to deliver double the
power from a single (mono) channel. It also
provides the following features:
• Powerful AB+B class circuitry yields maxi-
mum efficiency with minimum crossover
“notch” distortion.
•IOC®(Input/Output Comparator) alerts of
any distortion that exceeds 0.05% to pro-
vide proof of distortion-free performance.
• Signal presence indicators verify the pres-
ence of amplifier output.
• Detented level controls for precise repeat-
ability.
• Ultra-low harmonic and intermodulation
distortion result in the best dynamic trans-
fer function in the industry.
• Very low noise and wide dynamic range.
• High damping factor provides exceptional
loudspeaker motion control.
• Convection cooling system eliminates fan
noise and maintenance.
• Mounts in a standard 19-inch (48.3-cm)
rack.
• Front-panel headphone jack.
• Three Year, No-Fault, Fully-Transferable
Warranty completely protects your invest-
ment and guarantees its specifications.
1.2 How to Use This Manual
This manual provides you with the necessary
information to safely and correctly setup and
operate your amplifier. It does not cover every
aspect of installation, setup or operation that
might occur under every condition. For addi-
tional information, please consult Crown’s
Amplifier Application Guide (available online at
www.crownaudio.com), Crown Technical Sup-
port, your system installer or retailer.
We strongly recommend you read all instruc-
tions, warnings and cautions contained in this
manual. Also, for your protection, please send
in your warranty registration card today. And
save your bill of sale — it’s your official proof
of purchase.
SIGNAL
IOC
CHANNEL 1 CHANNEL 2
HEADPHONES POWER
OFF ON
LEVEL
30
50
40
0
10
20
LEVEL
30
50
40
0
10
20

Operation Manual
D Series Power Amplifiers
page 6
2.1 Unpack Your Amplifier
Please unpack and inspect your amplifier for any
damage that may have occurred during transit. If
damage is found, notify the transportation company
immediately. Only you can initiate a claim for ship-
ping damage. Crown will be happy to help as
needed. Save the shipping carton as evidence of
damage for the shipper’s inspection.
We also recommend that you save all packing mate-
rials so you will have them if you ever need to trans-
port the unit. Never ship the unit without the
factory pack.
YOU WILL NEED (not supplied):
• Input wiring cables
• Output wiring cables
Rack for mounting amplifier (or a stable surface for
stacking)
WARNING: Before you start to set up your
amplifier, make sure you read and observe
the Important Safety Instructions found at
the beginning of this
manual.
2.2 Install Your Amplifier
CAUTION: Before you begin, make sure your
amplifier is disconnected from the power
source, with the power switch in the “off”
position and all level controls turned com-
pletely down (counterclockwise).
Use a standard 19-inch (48.3 cm) equipment rack
(EIA RS-310B). See Figure 2.1 for amplifier dimen-
sions.
You may also stack amps without using a
cabinet.
NOTE: When transporting, amplifiers should be
supported at the front.
2.3 Ensure Proper Cooling
When using an equipment rack, do not mount units
directly on top of each other. Allow some air space
between units for convection cooling. The side
walls of the rack should be a minimum of two
inches (5.1 cm) away from the amplifier sides, and
the back of the rack should be a minimum of four
inches (10.2 cm) from the amplifier back panel.
Figure 2.2 illustrates D Series amplifier
installation.
Figure 2.1 D-45 and D-75A Dimensions
Figure 2.2 Installation
2 Setup

page 7
D Series Power Amplifiers
Operation Manual
2.4 Choose Input Wire
and Connectors
Figure 2.3 shows connector pin assignments for
balanced wiring, and Figure 2.4 shows connec-
tor pin assignments for unbalanced wiring.
NOTE: Custom wiring should only be per-
formed by qualified personnel.
2.5 Choose Output Wire and
Connectors
Crown recommends using professionally con-
structed, high-
quality, two- or four-conductor, heavy gauge
speaker wire and connectors. You may use ter-
minal forks or bare wire for your output connec-
tors (see Figure 2.5). To prevent the possibility
of short-circuits, wrap or otherwise insulate
exposed loudspeaker cable and connectors.
Using the guidelines below, select the appropri-
ate size of wire based on the distance from
amplifier to speaker.
CAUTION: Never use shielded cable for
output wiring.
Distance Wire Size
up to 25 ft. 16 AWG
26-40 ft. 14 AWG
41-60 ft. 12 AWG
Over 60 ft. 10 AWG
Figure 2.3 Balanced
Input Connector
Wiring
Figure 2.4 Unbalanced
Input Connector
Wiring
2 Setup
Figure 2.5 Output Connector Wiring

Operation Manual
D Series Power Amplifiers
page 8
2.6 Wire Your System
2.6.1 Dual Mode
Typical input and output wiring is shown in Figure 2.5.
INPUTS: Connect input wiring for each channel.
OUTPUTS: Maintain proper polarity (+/-) on output connec-
tors.
Connect Channel 1 positive (+) speaker load to Channel 1
positive terminal of amp; repeat for negative (-). Repeat each
channel wiring as for Channel 1. Refer to Section 2.5 for out-
put connector pin assignments.
2.6.2 Bridge-Mono Mode
Your amplifier is factory-configured for dual (stereo) opera-
tion. As an option, the unit can be configured for higher
power, single-channel, bridge-mono mode by an authorized
Crown Service Center. To prevent damage to the
amplifier, do not operate the unit in bridge-mono
mode without the Service Center modification.
Typical input and output wiring is shown in Figure 2.7.
INPUTS: Connect input wiring only to CH 1.
OUTPUTS: Connect the speaker across the positive output
terminals. Do not use the negative terminals when the ampli-
fier is being operated in Bridge-Mono mode.
NOTE: Crown provides a reference of wiring pin assign-
ments for commonly used connector types in the Crown
Amplifier Application Guide available at www.crownau-
dio.com.
NOTE: When operating in Bridge-Mono mode, turn
down (full CCW) the CH 2 level control. The CH 1
level control works both channels.
If your loudspeakers don’t need the additional volt-
age, and you only have one input signal to drive mul-
tiple loudspeakers, you can use bridge-mono mode
without actually bridging the outputs. Bridge-mono
mode is like dual mode except the channel 1 input
feeds both outputs, and the channel 2 output is
inverted. To use bridge-mono mode without bridging
the outputs, wire your loudspeakers as you would for
dual mode, but invert the polarity of the channel 2
output wiring (positive goes to negative, and negative
goes to positive).
2 Setup
Figure 2.6
System Wiring
for Dual Mode
Figure 2.7
System Wiring
for Bridge-Mono
Mode
Do not wire the amplifier in bridge-mono
mode without having it modified by an
authorized Crown Service Center.

page 9
D Series Power Amplifiers
Operation Manual
2.7 Connect to AC Mains
Connect your amplifier to the AC mains power
source (power outlet) with the supplied AC
power cordset.
WARNING: The third prong of this con-
nector (ground) is an important safety
feature. Do not attempt to disable this
ground connection by using an adapter
or other methods.
Amplifiers don’t create energy. The AC mains
voltage and current must be sufficient to deliver
the power you expect. You must operate your
amplifier from an AC mains power source with
not more than a 10% variation above or a 15%
variation below the amplifier’s specified line
voltage and within the specified frequency
requirements (indicated on the amplifier’s back
panel label). If you are unsure of the output
voltage of your AC mains, please consult your
electrician.
2.7.1 AC Mains Voltage Configura-
tion
North American 120 VAC, 60 Hz units have a
standard three wire, grounded AC plug as
specified by UL requirements. The 120 volt
models and the European models have the
appropriate plug. The other 200, 220 and 240
volt models have a North American 120 volt
plug. The installer must cut off the plug and
supply and install a plug appropriate for the
installation. Note: Crown assumes no liability
whatsoever for ungrounded operation, nor for
violation of UL or local electrical codes.
120 VAC, 60 Hz North American units do not
have a convertible transformer, and cannot be
used at other voltages and frequencies. Interna-
tional units can be operated with an AC mains
frequency of 50 to 400 Hz, and can be config-
ured by an authorized Crown Service Center for
five different line voltages: 100, 120, 200, 220
and 240 VAC. The back panel sticker indicates
the unit’s factory configuration.
To alter your amplifier’s AC mains voltage con-
figuration, take the unit to an authorized Crown
Service Center.
2.8 Startup Procedure
Use the following procedure when first turning
on your amplifier:
1. Turn down the level of your audio source.
2. Turn down the Level controls of the ampli-
fier.
3. Turn on the “Power” switch. The Power
indicator should glow.
4. Turn up the level of your audio source to
an optimum level.
5. Turn up the Level controls on the amplifier
until the desired loudness or power level is
achieved.
6. Turn down the level of your audio source
to its normal range.
If you ever need to make any wiring or installa-
tion changes, don’t forget to disconnect the
power cord.
For help with determining your system’s opti-
mum gain structure (signal levels) please refer
to the Crown Amplifier Application Guide,
available online at www.crownaudio.com.
2 Setup

Operation Manual
D Series Power Amplifiers
page 10
3.1 Precautions
Your amplifier is protected from internal and exter-
nal faults, but you should still take the following
precautions for optimum performance and safety:
1. Before use, your amplifier first must be config-
ured for proper operation, including input and
output wiring hookup. Improper wiring can
result in serious operating difficulties. For
information on wiring and configuration, please
consult the Setup section of this manual or, for
advanced setup techniques, consult Crown’s
Amplifier Application Guide available online at
www.crownaudio.com.
2. Use care when making connections, selecting
signal sources and controlling the output level.
The load you save may be your own!
3. Do not short the ground lead of an output cable
to the input signal ground. This may form a
ground loop and cause oscillations.
4. IMPORTANT: Headphone jack supplies
full output voltage. Always turn level
down (full CCW) before listening
through headphones; otherwise head-
phone or hearing damage may result.
3 Operation
5. WARNING: Never connect the output to
a power supply, battery or power main.
Electrical shock may result.
6. Tampering with the circuitry, or making unau-
thorized circuit changes may be hazardous and
invalidates all agency listings.
7. Do not operate the amplifier with the IOC LEDs
constantly flashing.
8. Do not overdrive the mixer, which will cause
clipped signal to be sent to the amplifier. Such
signals will be reproduced with extreme accu-
racy, and loudspeaker damage may result.
9. Do not operate the amplifier with less than the
rated load impedance. Due to the amplifier’s
output protection, such a configuration may
result in premature clipping and speaker dam-
age.
Remember: Crown is not liable for damage that
results from overdriving other system components.

page 11
D Series Power Amplifiers
Operation Manual
3.2 Controls, Indicators and Con-
nectors
Figure Figure 3.1 shows the controls, indica-
tors and connectors on the front panel and back
panel of the D-75A. The D-45 layout is similar.
Figure 3.1 Front and Back Views
3 Operation
WARNING: HEADPHONE JACK
SUPPLIES FULL OUTPUT POWER AND
MAY DAMAGE HEADPHONES OR
CAUSE HEARING DAMAGE.

Operation Manual
D Series Power Amplifiers
page 12
the unit’s fuse, you should be sure to fix the
source of the problem. If the problem is not
immediately apparent, the unit probably needs
to be serviced by a qualified technician.
WARNING: Always unplug the amplifier
from the AC mains before removing the
fuse.
To replace the fuse, turn off the power switch
and disconnect the power plug from the AC
mains. Unscrew the fuse holder cap (shown in
Figure 3.1, back view) and remove the fuse.
Install appropriate fuse:
100 or 120 volt mains: 2 Amp type 3AG.
North American 200, 220 and 240 volt mains: 1
Amp type 3AG.
European 220 or 240 volt mains: 1 Amp IEC
type T, time lag, low breaking capacity.
Then, simply resecure the fuse holder cap and
reconnect the AC mains.
IMPORTANT: Never install a fuse that
has a higher current rating than the rec-
ommended value.
IMPORTANT: The 3AG and IEC fuses are
different physical sizes and require dif-
ferent holder caps. The 3AG and IEC
fuses should not be exchanged even
though they are the same value.
.
Figure 3.2
Indicators and Level
Controls
3.3 Indicators
Your amplifier has five front panel indicators.
First, a power indicator behind the front panel
becomes visible when the unit is turned on and
has power. A signal indicator for each channel
(Figure 3.2) flashes when there is output from
the amplifier. The IOC (Input/Output Compara-
tor) indicators work like sensitive distortion
meters and flash when the amplifier causes any
distortion of 0.05% or more. The IOC indica-
tors typically glow for about one minute after
the AC power is turned off.
3.4 Controls
A power switch and detented level controls are
located on the front panel. When you power up
the amplifier, remember that the unit does not
have a turn-on delay. Each channel has its own
level control which is used to adjust the desired
output level. Both level controls (Figure 3.2)
are used in dual mode, but only the channel 1
control should be used in bridge-mono mode.
Channel 2 control should be fully counter-
clockwise in bridge-mono mode.
3.5 Fuse Replacement
The AC mains fuse is located on the back panel
beside the power cord. This fuse will not blow
unless something is wrong. Before replacing
3 Operation

page 13
D Series Power Amplifiers
Operation Manual
NOTE: For detailed information about
these Crown amplifier features, please
consult the Crown Amplifier Application
Guide, available on the Crown website
at www.crownaudio.com.
4.1 Protection
Your amplifier is protected against all common
hazards that plague high-power amplifiers,
including shorted, open or mismatched loads;
overloaded power supplies, chain destruction
phenomena, input overload and high-frequency
blowups.
Protection against shorted and mismatched
loads is provided by an instantaneous limiter
that automatically limits current to the maxi-
mum safe value for the output transistors. With
a loudspeaker, you can tell the amplifier has
activated load protection because it causes
audible distortion. The noise might be com-
pared to crossover notch distortion or a snap-
ping sound, depending on the load
characteristics. Loudspeaker systems with
impedances of 4 ohms or higher should not
activate the protection system.
All voltage amplification circuitry is designed to
limit current. So in the extremely unlikely event
of a device failure, the amplifier will prevent fur-
ther damage. The input stages are protected
from overload damage by series resistors. The
unit also features a controlled slew rate and a
V-I limiter that protect the amplifier from high-
frequency (RF) blowups.
4.2 Options
4.2.1 Bridge-Mono Option
Your amplifier is factory-set for dual (stereo)
operation. As an option, you may have the unit
configured for higher-power, single-channel,
bridge-mono operation. If you want the bridge-
mono modification, take the unit to an autho-
rized Crown Service Center.
IMPORTANT: Critical differences
between dual and mono wiring are
described in Section 2.6.2.
4.2.2 Input-Sensitivity Option
The input sensitivity of your amplifier is fac-
tory-set to 26 dB gain. As an option, the unit
can be set to an input sensitivity of 0.775 volt
by an authorized Crown Service center.
For most applications, the amplifier’s default
setting of 26 dB gain will be ideal. With this
default setting, full output power is achieved
with an input signal of 0.632 volts for the D-45,
and 0.837 volts for the D-75A.
Some applications may require the gain struc-
ture to be calculated based on a sensitivity of
0.775 volts. And although the 26 dB gain set-
ting provides a sensitivity for each amplifier
that is very near 0.775 volts, the 0.775-volt
sensitivity setting is provided for applications
that demand this sensitivity with a high level of
precision.
A Crown Service Center can activate the 0.775
volt input sensitivity without voiding the war-
ranty.
4 Advanced Features
and Options

Operation Manual
D Series Power Amplifiers
page 14
CONDITION: Power indicator is off.
POSSIBLE REASON
• The amplifier has lost AC power.
• The amplifier’s Power switch is off.
• The amplifier is not plugged into the
power receptacle.
• The amplifier output level is so high that
the power supply fuse has blown. Verify
that input levels and output impedances
are within safe ranges. Refer the unit to
an authorized Crown service center for
fuse replacement.
CONDITION: Distorted sound.
POSSIBLE REASON:
• Load is wired incorrectly.
• Input signal level is too high. Turn down
your amplifier level controls, or turn
down the input signal, until the clip light
goes out.
Note: If the signal sounds distorted even
though the Clip LED is off, the input signal is
distorted. Check gain staging and output lev-
els of the mixer or preamp.
5 Troubleshooting
CONDITION: No sound, even though
the amp has power. Power LED is on and
the amp is receiving an input signal. Signal
indicator is flashing.
POSSIBLE REASON:
• Speakers not connected.
• Open circuit due to speaker failure.
• There is a short on the amplifier
output. First disconnect your speakers
from the affected channel(s) one by one
to determine if one of the loads is
shorted.
CONDITION: No input signal.
(Signal indicator is not flashing even though
audio is applied).
POSSIBLE REASON:
• Input signal level is very low.
• Level controls are turned down.

page 15
D Series Power Amplifiers
Operation Manual
6 Specifications
Minimum Guaranteed Power D-45 D-75A
120V/60 Hz Units, Dual mode, per channel, both channels driven
1 kHz with 0.1% THD
4 ohms
8 ohms
16 ohms
35W
25W
20W
55W
40W
25W
120V/60 Hz Units, Bridge mono mode
1 kHz with 0.1% THD
8 ohms
16 ohms
70W
50W
110W
80W
Performance D D-455D- D-75AA
Frequency Response (at 1 watt, 20Hz - 20 kHz) ± 0.1 dB ± 0.1 dB
Phase Response (at 1 watt, 20Hz - 20 kHz) +10° to -15° +10° to -15°
Signal to Noise Ratio (below rated power, 20 Hz to 20 kHz) 106 dB unweighted 106 dB unweighted
Total Harmonic Distortion (THD) at 1 watt, from 20 Hz to 20 kHz < 0.05% < 0.05%
Intermodulation Distortion (IMD) 60 Hz and 7 kHz at 4:1,
from.25 watts to full bandwidth power < 0.01% < 0.01%
Damping Factor: DC to 400 Hz > 400 > 400
Crosstalk (below rated power, 100 Hz to 1 kHz) >100 dB > 100 dB
Input Impedance nominally balanced, nominally unbalanced 20 kilohms, 10 kilohms 20 kilohms, 10 kilohms
Load Impedance (Note: Safe with all types of loads)
Stereo
Bridge Mono
4-16 ohms
8-16 ohms
4-16 ohms
8-16 ohms
Required AC Mains
North American units
International units
120 VAC, 60 Hz
100, 120, 200, 220, and 240 VAC (± 10%), 50 to 400 Hz
depending on the transformer configuration
120 VAC, 60 Hz
100, 120, 200, 220, and 240 VAC (± 10%), 50 to 400 Hz
depending on the transformer configuration
Power Draw at Idle 15 W or less 15 W or less
Cooling Convection cooled through chassis and front panel Convection cooled through chassis and front panel
Dimensions: Width, Height, Depth 19 in. (48.3 cm) x 1.75 in. (4.5 cm) x 8.5 in. (21.6 cm) 19 in. (48.3 cm) x 1.75 in. (4.5 cm) x 8.5 in. (21.6 cm)
Net Weight, Shipping Weight 8 lb. 11 oz. (3.9 kg), 10 lb. 9 oz. (4.8 kg) 9 lb. 7 oz. (4.3 kg), 11 lb. 4 oz. (5.1 kg)

Operation Manual
D Series Power Amplifiers
page 16
D-45
Configuration and Load
(ohms)
FTC Continuous
Average Power at 0.1% THD
(See note 1)
Max. Aver-
age Power at
0.1% THD
(See note 2)
Single-Cycle Tone Burst
Watts at < 0.05% THD
(See note 3)
40 mS Tone Burst
Watts at < 0.05% THD
(See note 4)
EIA Watts at
1% THD
(See note 5)
20Hz-20kHz 1 kHz 1 kHz 20 Hz 50 Hz 1 kHz 20 Hz 50 Hz 1 kHz 1 kHz
Dual
(both channels
driven)
4 3540507555606035
820252525303540404025
16 20 20 20 20 20 20 20 20 20 20
Bridge-Mono
(balanced output)
8 70 85 105 145 85 85 85 70
16 40 50 50 50 60 70 50 50 55 50
6 Specifications
D-75A
Configuration and Load
(ohms)
FTC Continuous
Average Power at 0.1% THD
(See note 1)
Max. Aver-
age Power at
0.1% THD
(See note 2)
Single-Cycle Tone Burst
Watts at < 0.05% THD
(See note 3)
40 mS Tone Burst
Watts at < 0.05% THD
(See note 4)
EIA Watts at
1% THD
(See note 5)
20Hz-20kHz 1 kHz 1 kHz 20 Hz 50 Hz 1 kHz 20 Hz 50 Hz 1 kHz 1 kHz
Dual
(both channels
driven)
4 45 50 55 65 85 120 65 70 70 55
835404045506045454540
16 25 25 25 25 30 30 25 25 25 25
Bridge-Mono
(balanced output)
8 95 105 110 140 165 235 140 140 140 105
16 70 75 80 90 100 130 90 90 95 75
Figure 6.1 D-45 Power Matrix
Figure 6.2 D-75A Power Matrix
Notes:
All power matrix specifications are based on a 0.1% regulated 120 VAC, 60 Hz power mains and an ambient room temperature of 70° F (21° C).
1. Continuous power in the context of Federal Trade Commission testing is understood to be a minimum of five minutes of operation. Harmonic distortion is measured at the RMS sum total as a percentage of the fundamental output voltage. This applies for
all wattages greater than 0.25 watts.
2. A 1 kHz sine wave is presented to the amplifier and the output monitored for nonlinear distortion. The level is increased until the THD reaches 0.1%. At this level the average power per channel is reported.
3. A single cycle sine wave is presented to the amplifier and monitored for nonlinear distortion. The average power during the burst is reported. Loudspeakers must be able to withstand this level if they are to be safely used with this amplifier.
4. A 40 millisecond burst or a two cycle sine wave (whichever is of greater duration) is used and the power computed as the average power during the burst. The duty cycle of this test is 10 percent. This power level is a measure of how loud an amplifier is
as perceived by the human ear.
5. EIA standard RS-490 (both channels driven).

page 17
D Series Power Amplifiers
Operation Manual
Crown amplifiers are quality units that rarely require ser-
vicing. Before returning your unit for service, please con-
tact Crown Technical Support to verify the need for
servicing.
This unit has very sophisticated circuitry which should
only be serviced by a fully trained technician. This is one
reason why each unit bears the following label:
CAUTION: To prevent electric shock, do not
remove covers. No user serviceable parts
inside. Refer servicing to a qualified technician.
Complete the Crown Audio Factory Service Information
form, in the back of this manual, when returning a Crown
product to the factory or authorized service center. The
form must be included with your product inside the box
or in a packing slip envelope securely attached to the
outside of the shipping carton. Do not send this form
separately.
Warranty is only valid within the country in which the
product is purchased.
7.1 International and Canada Service
Service may be obtained from an authorized service cen-
ter. (Contact your local Crown/Amcron representative or
our office for a list of authorized service centers.) To
obtain service, simply present the bill of sale as proof of
purchase along with the defective unit to an authorized
service center. They will handle the necessary paperwork
and repair.
Remember to transport your unit in the original factory
pack.
7.2 US Service
Service may be obtained in one of two ways: from an
authorized service center or from the factory. You may
choose either. It is important that you have your copy of
the bill of sale as your proof of purchase.
7.2.1 Service at a US Service Center
This method usually saves the most time and effort. Sim-
ply present your bill of sale along with the defective unit
to an authorized service center to obtain service. They
will handle the necessary paperwork and repair. Remem-
ber to transport the unit in the original factory pack. A list
of authorized service centers in your area can be obtained
from Crown Factory Service, or online from
http://www.crownaudio.com/support/servcent.htm.
7.2.2 Factory Service
Crown accepts no responsibility for non-serviceable
product that is sent to us for factory repair. It is the
owner’s responsibility to ensure that their product is ser-
viceable prior to sending it to the factory. Serviceable
product list is available at
http://crownweb.crownintl.com/crownrma/.
For more information, please contact us direct.
A Service Return Authorization (SRA) is required for
product being sent to the factory for repair. An SRA can
be completed online at www.crownaudio.com/support/
factserv.htm. If you do not have access to the web, please
call Crown’s Customer Service at 574.294.8200 or
800.342.6939 extension 8205.
For warranty service, we will pay for ground shipping
both ways in the United States. Contact Crown Customer
Service to obtain prepaid shipping labels prior to send-
ing the unit. Or, if you prefer, you may prepay the cost of
shipping, and Crown will reimburse you. Send copies of
the shipping receipts to Crown to receive reimbursement.
Your repaired unit will be returned via UPS ground.
Please contact us if other arrangements are required.
7.2.3 Factory Service Shipping Instruc-
tions:
1. Service Return Authorization (SRA) is required for
product being sent to the factory for service. Please
complete the SRA by going to
www.crownaudio.com/support/factserv.htm. If you
do not have access to our website, call
1.800.342.6939, extension 8205 and we'll create the
SRA for you.
2. See packing instructions that follow.
3. Ship product to:
CROWN AUDIO FACTORY SERVICE
1718 W MISHAWKA RD.
ELKHART, IN 46517
4. Use a bold black marker and write the SRA number
on three sides of the box.
5. Record the SRA number for future reference. The
SRA number can be used to check the repair status.
7.2.4 Packing Instructions
Important: These instructions must be followed. If they
are not followed, Crown Audio, Inc. assumes no respon-
sibility for damaged goods and/or accessories that are
sent with your unit.
1. Fill out and include the Crown Audio Factory Ser-
vice Information sheet in the back of this manual.
2. Do not ship any accessories (manuals, cords, hard-
ware, etc.) with your unit. These items are not
needed to service your product. We will not be
responsibility for these items.
3. When shipping your Crown product, it is important
that it has adequate protection. We recommend you
use the original pack material when returning the
product for repair. If you do not have the original
box, please call Crown at 800.342.6939 or
574.294.8210 and order new pack material. See
instructions for “foam-in-place” shipping pack. (Do
not ship your unit in a wood or metal cabinet.)
4. If you provide your own shipping pack, the mini-
mum recommended requirements for materials are
as follows:
a. 275 P.S.I. burst test, Double-Wall carton that allows
for 2-inch solid Styrofoam on all six sides of unit or
3 inches of plastic bubble wrap on all six sides of
unit.
b. Securely seal the package with an adequate carton
sealing tape.
c. Do not use light boxes or “peanuts”. Damage caused
by poor packaging will not be covered under war-
ranty.
Using your 'foam-in-place' shipping pack
Note: The foam-in-place packing is molded so that there
is only one correct position for your product.
1. Open carton and lift center cushion leaving both
end-cushions in place.
7 Service
2. Carefully place your product with the product's front
panel facing the same direction as arrows indicate.
3. Reset center cushion down over top of product's
chassis. The foam-in-place packing was molded to
accommodate different chassis depth sizes. If your
product's chassis does not completely fill the foam-
in-place cavity, you may use a soft but solid packing
material (such as paper or bubble wrap) behind the
chassis.
4. Enclose the completed Crown Audio Factory Service
Information form (or securely attach it to the outside
of carton) and re-seal the shipping pack with a
sturdy carton sealing tape.
7.2.5 Estimate Approval
Approval of estimate must be given within 30 days after
being notified by Crown Audio Inc. Units still in the pos-
session of Crown after 30 days of the estimate will
become the property of Crown Audio Inc.
7.2.6 Payment of Non-Warranty Repairs
Payment on out-of-warranty repairs must be received
within 30 days of the repair date. Units unclaimed after
30 days become the property of Crown Audio Inc.
If you have any questions, please contact Crown Factory
Service.
Crown Factory Service
1718 W. Mishawaka Rd.,
Elkhart, Indiana 46517 U.S.A.
Telephone:
574.294.8200
800.342.6939 (North America,
Puerto Rico, and Virgin Islands only)
Facsimile:
574.294.8301 (Technical Support)
574.294.8124 (Factory Service)
Internet:
http://www.crownaudio.com

Operation Manual
D Series Power Amplifiers
page 18
8 Warranty
SUMMARY OF WARRANTY
Crown International, 1718 West Mishawaka Road,
Elkhart, Indiana 46517-4095 U.S.A. warrants to
you, the ORIGINAL PURCHASER and ANY SUB-
SEQUENT OWNER of each NEW Crown product,
for a period of three (3) years from the date of
purchase by the original purchaser (the “warranty
period”) that the new Crown product is free of
defects in materials and workmanship. We further
warrant the new Crown product regardless of the
reason for failure, except as excluded in this War-
ranty.
Warranty is only valid within the country in which
the product was purchased.
ITEMS EXCLUDED FROM THIS
CROWN WARRANTY
This Crown Warranty is in effect only for failure of
a new Crown product which occurred within the
Warranty Period. It does not cover any product
which has been damaged because of any inten-
tional misuse, accident, negligence, or loss which
is covered under any of your insurance contracts.
This Crown Warranty also does not extend to the
new Crown product if the serial number has been
defaced, altered, or removed.
WHAT THE WARRANTOR WILL DO
We will remedy any defect, regardless of the rea-
son for failure (except as excluded), by repair,
replacement, or refund. We may not elect refund
unless you agree, or unless we are unable to pro-
vide replacement, and repair is not practical or
cannot be timely made. If a refund is elected, then
you must make the defective or malfunctioning
product available to us free and clear of all liens
or other encumbrances. The refund will be equal
to the actual purchase price, not including inter-
est, insurance, closing costs, and other finance
charges less a reasonable depreciation on the
product from the date of original purchase. War-
ranty work can only be performed at our autho-
rized service centers or at the factory. Warranty
work for some products can only be performed at
our factory. We will remedy the defect and ship
the product from the service center or our factory
within a reasonable time after receipt of the defec-
tive product at our authorized service center or
our factory. All expenses in remedying the defect,
including surface shipping costs in the United
States, will be borne by us. (You must bear the
expense of shipping the product between any for-
eign country and the port of entry in the United
States including the return shipment, and all
taxes, duties, and other customs fees for such for-
eign shipments.)
HOW TO OBTAIN WARRANTY
SERVICE
You must notify us of your need for warranty ser-
vice within the warranty period. All components
must be shipped in a factory pack, which, if
needed, may be obtained from us free of charge.
Corrective action will be taken within a reason-
able time of the date of receipt of the defective
product by us or our authorized service center. If
the repairs made by us or our authorized service
center are not satisfactory, notify us or our autho-
rized service center immediately.
DISCLAIMER OF CONSEQUENTIAL
AND INCIDENTAL DAMAGES
YOU ARE NOT ENTITLED TO RECOVER FROM
US ANY INCIDENTAL DAMAGES RESULTING
FROM ANY DEFECT IN THE NEW CROWN
PRODUCT. THIS INCLUDES ANY DAMAGE TO
ANOTHER PRODUCT OR PRODUCTS RESULT-
ING FROM SUCH A DEFECT. SOME STATES DO
NOT ALLOW THE EXCLUSION OR LIMITATIONS
OF INCIDENTAL OR CONSEQUENTIAL DAM-
AGES, SO THE ABOVE LIMITATION OR EXCLU-
SION MAY NOT APPLY TO YOU.
WARRANTY ALTERATIONS
No person has the authority to enlarge, amend, or
modify this Crown Warranty. This Crown War-
ranty is not extended by the length of time which
you are deprived of the use of the new Crown
product. Repairs and replacement parts provided
under the terms of this Crown Warranty shall
carry only the unexpired portion of this Crown
Warranty.
DESIGN CHANGES
We reserve the right to change the design of any
product from time to time without notice and with
no obligation to make corresponding changes in
products previously manufactured.
LEGAL REMEDIES OF PURCHASER
THIS CROWN WARRANTY GIVES YOU SPECIFIC
LEGAL RIGHTS, YOU MAY ALSO HAVE OTHER
RIGHTS WHICH VARY FROM STATE TO STATE.
No action to enforce this Crown Warranty shall be
commenced after expiration of the warranty
period.
THIS STATEMENT OF WARRANTY SUPERSEDES
ANY OTHERS CONTAINED IN THIS MANUAL
FOR CROWN PRODUCTS. 9/07
UNITED STATES & CANADA

page 19
D Series Power Amplifiers
Operation Manual
8 Warranty WORLDWIDE EXCEPT USA & CANADA
SUMMARY OF WARRANTY
Crown International, 1718 West Mishawaka Road,
Elkhart, Indiana 46517-4095 U.S.A. warrants to
you, the ORIGINAL PURCHASER and ANY SUB-
SEQUENT OWNER of each NEW Crown1 product,
for a period of three (3) years from the date of pur-
chase by the original purchaser (the “warranty
period”) that the new Crown product is free of
defects in materials and workmanship, and we
further warrant the new Crown product regardless
of the reason for failure, except as excluded in this
Warranty.
Warranty is only valid within the country in which
the product is purchased.
1 Note: If your unit bears the name “Amcron,” please substitute
it for the name “Crown” in this warranty.
ITEMS EXCLUDED FROM THIS CROWN-
WARRANTY
This Crown Warranty is in effect only for failure of
a new Crown product which occurred within the
Warranty Period. It does not cover any product
which has been damaged because of any inten-
tional misuse, accident, negligence, or loss which
is covered under any of your insurance contracts.
This Crown Warranty also does not extend to the
new Crown product if the serial number has been
defaced, altered, or removed.
WHAT THE WARRANTOR WILL DO
We will remedy any defect, regardless of the rea-
son for failure (except as excluded), by repair,
replacement, or refund. We may not elect refund
unless you agree, or unless we are unable to pro-
vide replacement, and repair is not practical or
cannot be timely made. If a refund is elected, then
you must make the defective or malfunctioning
product available to us free and clear of all liens
or other encumbrances. The refund will be equal
to the actual purchase price, not including inter-
est, insurance, closing costs, and other finance
charges less a reasonable depreciation on the
product from the date of original purchase. War-
ranty work can only be performed at our autho-
rized service centers. We will remedy the defect
and ship the product from the service center
within a reasonable time after receipt of the defec-
tive product at our authorized service center.
HOW TO OBTAIN WARRANTY SERVICE
You must notify your local Crown importer of
your need for warranty service within the warranty
period. All components must be shipped in the
original box. Corrective action will be taken within
a reasonable time of the date of receipt of the
defective product by our authorized service center.
If the repairs made by our authorized service cen-
ter are not satisfactory, notify our authorized ser-
vice center immediately.
DISCLAIMER OF CONSEQUENTIAL AND
INCIDENTAL DAMAGES
YOU ARE NOT ENTITLED TO RECOVER FROM US
ANY INCIDENTAL DAMAGES RESULTING FROM
ANY DEFECT IN THE NEW CROWN PRODUCT.
THIS INCLUDES ANY DAMAGE TO ANOTHER
PRODUCT OR PRODUCTS RESULTING FROM
SUCH A DEFECT.
WARRANTY ALTERATIONS
No person has the authority to enlarge, amend, or
modify this Crown Warranty. This Crown Warranty
is not extended by the length of time which you are
deprived of the use of the new Crown product.
Repairs and replacement parts provided under the
terms of this Crown Warranty shall carry only the
unexpired portion of this Crown Warranty.
DESIGN CHANGES
We reserve the right to change the design of any
product from time to time without notice and with
no obligation to make corresponding changes in
products previously manufactured.
LEGAL REMEDIES OF PURCHASER
No action to enforce this Crown Warranty shall be
commenced after expiration of the warranty
period.
THIS STATEMENT OF WARRANTY SUPERSEDES
ANY OTHERS CONTAINED IN THIS MANUAL FOR
CROWN PRODUCTS. 9/07

Operation Manual
D Series Power Amplifiers
page 20
NOTES