Crown Com Tech 1600, Com Tech 200, Com Tech 400, Com Tech 800, CT-1600 Owners manual

COM-TE CH

®

ODEP

IOC

SPI

CH1 CH2

ODEP

IOC

SPI

CH1 CH2

ODEP

IOC

SPI

CH1 CH2

ODEP

IOC

SPI

CH1 CH2

ENABLE

POWER

OFF

ENABLE

POWER

OFF

ENABLE

POWER

OFF

ENABLE

POWER

OFF

Models:

Com-Tech 200, 400, 800 & 1600

Some models may be exported under the name

Amcron

Copyright ©1995 by Crown International, Inc., P.O. Box 1000, Elkhart, Indiana 46515-1000 U.S.A.
Telephone: [phone]. Com-Tech amplifiers are produced by the Professional Audio Division of
Crown International, Inc. Trademark Notice:

™

bridge

are trademarks and

and

®

TEF

are registered trademarks of Crown International, Inc. Other trademarks are the property of

Amcron

,®

Crown

SmartAmp

,®

Techron

,™

MPX-6

,®

Com-Tech

,™

,®

SMX-6

IOC

,™

,®

ODEP

AMB-5

their respective owners.

Approved for
THX Theatre

Systems

(CT-400 & 800)

120 VAC

North

American

Units:

Commercial
Audio

®

E106377

®

Fire Protective
Signaling
S5206

®

.

™

and

,®

IQ System

Grounded

,®

P.I.P.

®

Commercial

®

Audio
LL 32521C

K80636-2

3/95

3

YEAR

THREE YEAR

FULL WARRANTY

3

YEAR

WORLDWIDE

The Crown Audio Division of Crown International, Inc., 1718 West
Mishawaka Road, Elkhart, Indiana 46517-4095 U.S.A. warrants to you,
the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of
each NEW Crown
of purchase 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 Crown Warranty.

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 intentional 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.

We will remedy any defect, regardless of the reason for failure (except as
excluded), by repair, replacement, or refund. We may not elect refund
unless you agree, or unless we are unable to provide 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 interest, insurance, closing
costs, and other finance charges less a reasonable depreciation on the
product from the date of original purchase. Warranty work can only be
performed at our authorized service centers. We will remedy the defect
and ship the product from the service center within a reasonable time
after receipt of the defective product at our authorized service center. All
expenses in remedying the defect, including surface shipping costs to
the nearest authorized service center, will be borne by us. (You must
bear the expense of all taxes, duties and other customs fees when
transporting the product.)

You must notify us of your need for warranty service not later than ninety
(90) days after expiration of the warranty period. All components must be
shipped in a factory pack. 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
center are not satisfactory, notify our authorized 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 RESULTING FROM SUCH A
DEFECT.

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.

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.

No action to enforce this Crown Warranty shall be commenced later than
ninety (90) days after expiration of the warranty period.

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS

CONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.

Telephone: [phone]. Facsimile: 219-294-8301

SUMMARY OF WARRANTY

1

product, for a period of three (3) years from the date

WHAT THE WARRANTOR WILL DO

HOW TO OBTAIN WARRANTY SERVICE

WARRANTY ALTERATIONS

DESIGN CHANGES

LEGAL REMEDIES OF PURCHASER

9/90

NORTH AMERICA

The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka
Road, Elkhart, Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL
PURCHASER and ANY SUBSEQUENT 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, and we further warrant the new Crown product
regardless of the reason for failure, except as excluded in this Crown
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 intentional 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.

We will remedy any defect, regardless of the reason for failure (except as
excluded), by repair, replacement, or refund. We may not elect refund unless
you agree, or unless we are unable to provide 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 interest, insurance, closing costs, and other finance charges less
a reasonable depreciation on the product from the date of original purchase.
Warranty work can only be performed at our authorized service centers or at
the 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 defective
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 foreign country and the port of entry in the United States and all
taxes, duties, and other customs fees for such foreign shipments.)

You must notify us of your need for warranty service not later than ninety (90)
days after expiration of 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 reasonable 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 authorized 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 RESULTING FROM SUCH A DEFECT. SOME STATES DO

NOT ALLOW THE EXCLUSION OR LIMITATIONS OF INCIDENTAL OR
CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR
EXCLUSION MAY NOT APPLY TO YOU.

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.

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.

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 later
than ninety (90) days after expiration of the warranty period.

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS

CONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.

Telephone: [phone]. Facsimile: 219-294-8301

SUMMARY OF WARRANTY

WHAT THE WARRANTOR WILL DO

HOW TO OBTAIN WARRANTY SERVICE

WARRANTY ALTERATIONS

DESIGN CHANGES

LEGAL REMEDIES OF PURCHASER

9/90

The information furnished in 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. If your unit bears the name “Amcron,” please substitute it for the name “Crown” in this manual.
If you need special assistance beyond the scope of this manual, please contact our T echnical Support Group.

Crown Audio Division Technical Support Group

57620 C.R. 105, Elkhart, Indiana 46517 U.S.A.

Phone: [phone] Fax: [phone]

Toll Free in Canada, Puerto Rico, the United

States & Virgin Islands: 1-800-342-6939

FIRE PROTECTIVE SIGNALING

THIS AMPLIFIER IS UL-LISTED FOR FIRE

PROTECTIVE SIGNALING SYSTEMS.

REFER TO SECTION 9 FOR DETAILS

CAUTION

CLASS 1 OUTPUT WIRING REQUIRED.

C A U T I O N

RISK OF ELECTRIC SHOCK

DO NOT OPEN

TO PREVENT ELECTRIC SHOCK DO

NOT REMOVE TOP OR BOTTOM
COVERS. NO USER SERVICEABLE
PARTS INSIDE. REFER SERVICING

TO QUALIFIED SERVICE PERSON­NEL. DISCONNECT POWER CORD

BEFORE REMOVING REAR INPUT

MODULE TO ACCESS GAIN SWITCH.

WARNING

TO REDUCE THE RISK OF ELECTRIC

SHOCK, DO NOT EXPOSE THIS

EQUIPMENT TO RAIN OR MOISTURE!

A V I S

RISQUE DE CHOC ÉLECTRIQUE

N’OUVREZ PAS

À PRÉVENIR LE CHOC

ÉLECTRIQUE N’ENLEVEZ

PAS LES COUVERCLES.

RIEN DES PARTIES

UTILES À L’INTÉRIEUR.

DÉBRANCHER LA BORNE

AVANT D’OUVRIR LA

MODULE EN ARRIÈRE.

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 amplifier(s) in the bottom of the rack and the pream­plifier or other sensitive equipment at the top.

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.

Printed on

recycled paper.

Com-Tech 200/400/800/1600 Power Amplifiers

CONTENTS

1 Welcome ........................................................................... 7

1.1 Unpacking................................................................. 7

1.2 Features .................................................................... 7

2 Facilities ............................................................................ 8

3 Installation ....................................................................... 10

3.1 Mounting.................................................................. 10

3.2 Cooling .................................................................... 10

3.2.1 Cooling for Units without Internal Fans ........... 11

3.2.2 Additional Cooling for Units with Internal Fans 11

3.3 Wiring ...................................................................... 12

3.3.1 Mode of Operation........................................ 12

3.3.2 Input Connection .......................................... 17

3.3.3 Output Connection ....................................... 18

3.3.4 Additional Load Protection ........................... 20

3.4 AC Mains Power...................................................... 21

4 Operation ........................................................................ 22

4.1 Precautions ............................................................. 22

4.2 Indicators ................................................................ 22

4.3 Protection Systems ................................................. 23

4.3.1

ODEP ............................................................

4.3.2 Standby Mode .............................................. 24

4.3.3 Transformer Thermal Protection ................... 24

4.3.4 Circuit Breaker.............................................. 24

4.4 Controls................................................................... 25

4.5 Filter Cleaning ......................................................... 25

23

5 Technical Information...................................................... 26

5.1 Overview ................................................................. 26

5.2 Circuit Theory.......................................................... 26

5.2.1 Dual Operation ............................................. 26

5.2.2 Bridge-Mono Operation................................ 28

5.2.3 Parallel-Mono Operation............................... 28

6 Specifications .................................................................. 29

7 AC Power Draw and Thermal Dissipation ....................... 42

8 Accessories..................................................................... 44

8.1

P.I.P.

Modules ......................................................... 44

8.2 Cooling Fan Option (120 VAC, 60 Hz only)............. 46

8.3 Constant Voltage Computer.................................... 46

9 Fire Protective Signaling ................................................. 47

10 Service ............................................................................ 48

10.1 Worldwide Service ................................................. 48

10.2 North American Service ......................................... 48

10.2.1 Service at a North American Service Center 48

10.2.2 Factory Service ............................................ 48

Page 4

Com-Tech 200/400/800/1600 Power Amplifiers

1.1

Com-Tech

2.1 Front Facilities ........................................................................... 8

2.2 Rear Facilities............................................................................ 9

3.1 Mounting Dimensions.............................................................. 10

3.2 Top View of a Rack-Mounted Unit........................................... 11

3.3 Extra Cooling with a Rack-Mounted Blower ............................ 12

3.4 Wiring for Dual 8/4 Ohm Mode................................................ 13

3.5 Wiring for Dual 70 Volt Mode................................................... 14

3.6 Wiring for Bridge-Mono 70 Volt Mode (140 Volt Output)......... 15

3.7 Wiring for Parallel-Mono 70 Volt, Bridge-Mono 8/4 Ohm

and Parallel-Mono 8/4 Ohm Modes......................................... 16

3.8 Unbalanced Input Wiring ........................................................ 17

3.9 Balanced Input Wiring............................................................. 17

3.10 Subsonic Filter Capacitor Values ............................................17

3.11 Unbalanced RFI Filters............................................................ 18

3.12 Balanced RFI Filters ................................................................ 18

3.13 Wire Size Nomograph ............................................................. 19

3.14 Inductive Load (Transformer) Network.................................... 20

3.15 Loudspeaker Fuse Nomograph .............................................. 20

4.1

ODEP, IOC

4.2 Input Sensitivity Switch............................................................ 25

5.1 Circuit Block Diagram ............................................................. 27

6.1

Com-Tech 200

6.2

Com-Tech 400

6.3

Com-Tech 800

6.4

Com-Tech 1600

6.5

Com-Tech 200

6.6

Com-Tech 400

6.7

Com-Tech 800

6.8

Com-Tech 1600

6.9 Typical Frequency Response ................................................. 40

6.10 Typical Damping Factor .......................................................... 40

6.11 Typical Output Impedance...................................................... 40

6.12 Typical Phase Response......................................................... 41

6.13 Typical Crosstalk ..................................................................... 41

7.1

Com-Tech 200

Thermal Dissipation at Various Duty Cycles........................... 42

7.2

Com-Tech 400

Thermal Dissipation at Various Duty Cycles........................... 43

7.3

Com-Tech 800

Thermal Dissipation at Various Duty Cycles........................... 43

Com-Tech 1600

7.4

Thermal Dissipation at Various Duty Cycles........................... 43

8.1 Installing a

8.2 Cooling Fan Option ................................................................. 46

8.3 Cooling Fan Assembly ............................................................ 46

Amplifiers (120 VAC, 60 Hz Units)........................... 6

and Signal Presence Indicator States .................. 23

Minimum Power Matrix ................................... 32

Minimum Power Matrix ................................... 33

Minimum Power Matrix ................................... 34

Minimum Power Matrix ................................. 35

Maximum Power Matrix .................................. 36

Maximum Power Matrix .................................. 37

Maximum Power Matrix .................................. 38

Maximum Power Matrix ................................ 39

Power Draw, Current Draw and
Power Draw, Current Draw and
Power Draw, Current Draw and

P.I.P.

ILLUSTRATIONS

Power Draw, Current Draw and

Module......................................................... 44

Page 5

Com-Tech 200/400/800/1600 Power Amplifiers

ODEP

IOC

SPI

CH1 CH2

ODEP

IOC

SPI

CH1 CH2

ODEP

IOC

SPI

CH1 CH2

ENABLE

POWER

OFF

ENABLE

POWER

OFF

ENABLE

POWER

OFF

Page 6

ODEP

IOC

SPI

CH1 CH2

Fig. 1.1 Com-Tech Amplifiers (120 VAC, 60 Hz Units)

ENABLE

POWER

OFF

Com-Tech 200/400/800/1600 Power Amplifiers

1 Welcome

Congratulations on your purchase of a
commercial power amplifier. The

Com-Tech

complete family of amplifiers with a wide range of
power output capabilities.

Com-Tech

directly drive “constant voltage” lines, so you can
avoid the expense, distortion and insertion loss associ­ated with step-up transformers for distributed
loudspeaker systems.
Crown’s patented

keeps the amplifier working

Com-Tech

ODEP

®

protection circuitry which

under severe conditions

amplifiers also utilize

that would shut down a lesser amplifier. All
amplifiers feature Crown’s exclusive
mable Input Processor) expansion system. The
expansion system makes it easy to tailor your amplifier
to a specific application or to add future technology as
it develops (see Section 8 for a list of available

This manual will help you successfully install and use
your new

Com-Tech

amplifier. Please read all instruc-

tions, warnings and cautions. Be sure to read Section

3.3.1 if you plan to use the amplifier in one of its two
mono modes, or if you plan to drive “constant voltage”
lines. Also for your protection, please send in your war­ranty registration card today and save your bill of sale
as it is your official proof of purchase.

1.1 Unpacking

Please unpack and inspect your new amplifier for any
damage that may have occurred during transit. If dam­age is found, notify the transportation company imme­diately. Only you, the consignee, may initiate a claim
for shipping damage. Crown will be happy to cooper­ate fully as needed. Save the shipping carton as evi­dence of damage for the shipper’s inspection.

Even if the unit arrived in perfect condition, as most do,
save all packing materials so you will have them if you
ever need to transport the unit. NEVER SHIP THE

UNIT WITHOUT THE FACTORY PACK.

1.2 Features

Com-Tech

miniaturized design to provide the highest power and
value for its size, weight and price. They offer numer­ous advantages over conventional designs and pro­vide benefits you can’t get in amplifiers from any other
manufacturer. For example, Crown’s patented

amplifiers use cutting edge technology and

Com-Tech

series is a

amplifiers can

Com-Tech

®

P.I.P.

(Program-

P.I.P.

P.I.P.s

ODEP

®

protection circuitry

and grounded bridge

stages combine to provide performance and reliability
that surpass the other more traditional designs. Here
are some more of your amplifier’s impressive features:

❏ Crown’s patented

Protection) circuitry detects and compensates for
overheating and overload to keep the amplifier working
when others would fail.

❏ Crown’s

voltage swings without using stressful output transistor
configurations like conventional amplifiers. The results
are lower distortion and superior reliability.

❏

IOC

alerts you if any type of distortion exceeds 0.05%. We

).

provide this feature so you will have real-time

distortion-free performance

❏

P.I.P.

accepts accessories that tailor the amplifier to suit
specific applications.

❏ Drives constant voltage lines without “lossy,” distortion-

producing step-up transformers.

❏ Two mono modes (Bridge-Mono and Parallel-Mono) for

driving a wide range of load impedances.

❏ Very low harmonic and intermodulation distortion give

the best

❏ Superior damping factor delivers maximum loud-

speaker motion control for a clean, accurate low end.

❏ Superb crosstalk characteristics and a separate

voltage supply for each channel make it possible to
treat each channel like a separate amplifier.

❏ Full protection from shorted, open and mismatched

loads, general overheating, DC and high-frequency
overloads. Full internal fault protection.

❏ Efficient heat sinks and three-speed fan dissipate heat

quickly and evenly for extra amplifier protection and
extended component life. (The fan is an option for
120 VAC, 60 Hz

❏ Barrier blocks are provided for input and output

connections.

❏ Internal three-position input sensitivity switch provides

settings of 0.775 volts for full standard 1 kHz 8/4 ohm
power, 0.775 volts for full standard 1 kHz 70 volt power,
and 26 dB voltage gain.

❏ Mounts in a standard 19 inch (48.3 cm) equipment rack

(units can also be stacked).

❏ Three year “No-Fault” full warranty completely protects

your investment and guarantees its specifications.

grounded bridge

®

(Input/Output Comparator) circuitry immediately

(Programmable Input Processor) connector

dynamic transfer function

Com-Tech 200s

®

ODEP

(Output Device Emulation

™

design delivers incredible

.

in the industry.

.)

™

output

proof of

Page 7

Com-Tech 200/400/800/1600 Power Amplifiers

ODEP

IOC

SPI

CH1 CH2

A B EDC CDE F G

Fig. 2.1 Front Facilities

ENABLE

2 Facilities

A. Filter Grille

A metal grille supports and protects the dust filter (B).
To clean the dust filter, detach the grille by removing
the screws that fasten it in place.

B. Dust Filter

The dust filter removes large particles from air drawn
by the cooling fan. (The fan is an option for 120 VAC,
60 Hz
prevent clogging (see Section 4.5).

C.

During normal operation of the Output Device Emula­tion Protection circuitry, these green indicators glow
brightly to show the presence of reserve thermal-dy­namic energy. They dim proportionally as energy re­serves decrease. In the rare event that energy
reserves are depleted, the indicators turn off and

ODEP

can safely continue operating even under severe con­ditions. These indicators can also help to identify more
unusual operating problems (see Section 4.2).

D.

The yellow
serve as sensitive distortion indicators to provide

of distortion-free performance

tions, the indicators remain off. They light up if the out­put waveform differs from the input by 0.05% or more
(see Section 4.2).

will stay on in Parallel-Mono mode.

Com-Tech 200s

ODEP

Indicators

.) Check the filter regularly to

proportionally limits output drive so the amplifier

IOC

Indicators

IOC

(Input/Output Comparator) indicators

. Under normal condi-

Note: The channel 2 IOC indicator

proof

E. Signal Presence Indicators (SPI)

The signal presence indicators flash synchronously
with the amplifier’s audio output (see Section 4.2).

F. Enable Indicator

This indicator lights when the amplifier has been “en­abled” or turned on, and AC power is available (see
Section 4.2).

G. Enable Switch

This rocker switch is used to turn the amplifier on and
off. When turned on, the output is muted for about four
seconds to protect your system from turn-on tran­sients. Delay times vary slightly from one unit to the
next, so there is always a certain amount of “random­ness” in the turn-on timing of multiple units. In addition,
turn-on occurs at zero crossing of the AC waveform, so

Com-Tech

amplifiers rarely need a power sequencer.
(To change the turn-on delay time, contact Crown’s
Technical Support Group.) See Section 4.4.

H. Power Cord

All 120 VAC, 60 Hz North American units have a
NEMA 5-15P plug with an integral voltage presence
lamp. These units include a 16 gauge power cord with

Com-Tech 200s
Com-Tech 800s

propriate power cord and plug for the required AC
voltage. Refer to Section 7 for more information on
power usage.

and

and

400s

, and a 14 gauge cord with

1600s

. Other units have an ap-

POWER

OFF

Page 8

Com-Tech 200/400/800/1600 Power Amplifiers

REG. U.S. PAT. OFF.

4,330,809
4,611,180

MODEL: COM-TECH 200
AC VOLTS: 120 AMPS: 3.5 60 Hz

RATED OUTPUT: 150 W/CH INTO 4 OHMS
AT 1 KHz WITH 0.1% OR LESS THD.

REFER TO OWNER'S MANUAL K80636-2
FOR FIRE PROTECTIVE SIGNALING USE.

CAUTION:

BOTH CHANNELS MUST
BE CONFIGURED THE SAME (8/4 OHM
OR 70 VOLT) BEFORE USING EITHER
BRIDGE- OR PARALLEL-MONO MODE.

PUSH TO RESET

S

E

S

R

P

R

T

E

E

S

MODEL: COM-TECH 400 SERIES

®

INTERNATIONAL, INC.

AC VOLTS: 120 AMPS: 5.5 60 Hz

ELECTRONIC EQUIPMENT

MAXIMUM OUTPUT: 200 W/CH INTO 4

ELKHART, IN 46517

OHMS AT 1 KHz WITH 0.1% OR LESS THD.

MADE IN U.S.A.

000000

SERIAL NUMBER

REFER TO USER'S MANUAL K80548-9
FOR FIRE PROTECTIVE SIGNALING USE.

DUAL

PARALLEL

MONO

CAUTION:

TURN OFF AMPLIFIER

BEFORE CHANGING THIS SWITCH!

0000

BRIDGE

MONO

BB

Programmable
Input Processor (P.I.P.)

THIS AMPLIFIER IS EQUIPPED WITH SELECTABLE INPUT SENSITIVITY. REMOVE P.I.P. MODULE TO ACCESS SENSITIVITY SWITCH.

15
17
19
21
25

32

CH-2 INPUT

910

8

11

13

7

6

5

4

3

2

1

.5

0

dB

∞

CH-2 CH-1INPUT ATTENUATION

HJ LKOMI L N

Fig. 2.2 Rear Facilities

I. Reset Switch

This reset switch is used to reset the circuit breaker
that protects the power supplies from overload (see
Sections 4.3.4 and 4.4).

J. Dual/Mono Switch

Slide this switch to the center for Dual (two-channel)
mode, to the left for Parallel-Mono mode or to the right
for Bridge-Mono mode. WARNING: Do not change this

switch unless the amplifier is turned off. Do not attempt
to use the Bridge-Mono or Parallel-Mono modes unless
both output mode switches (N) are set the same. Also,

be sure to follow the installation requirements for each
mode (see Section 3.3.1).

K.

P.I.P.

The standard
It provides barrier block input connectors. Other
modules can be used in place of the

Module

P.I.P.-BB

is included with your amplifier.

P.I.P.

P.I.P.-BB

to pro­vide additional features that customize the amplifier for
different applications (see Section 8 for available

P.I.P.

modules).

❑ Input Sensitivity Switch

The three position input sensitivity switch located in­side the amplifier is accessed by removing the
module. It is set at the factory to 0.775 volts for stan­dard 1 kHz power into 8 ohms. It can also be set to

0.775 volts for standard 1 kHz output in 70 volt mode,
or a standard voltage gain of 26 dB (see Section 4.4).

P.I.P.

–+

CH-1 INPUT

–+

910

11

13

15

17
19
21
25

32

dB

∞

8/4

OHM

8

7

6

5

4
3
2

BRIDGE-MONO:

1

OFF. 2) SET DUAL/MONO SWITCH TO

.5

0

BRIDGE-MONO. 3) OUTPUT ACROSS “
TERMINALS ONLY (CH-1 IS POSTIVE).

70

8/4

VOLT

OHM

+ +

CH-2 OUTPUT CH-1 OUTPUT

1) TURN AMPLIFIER

PARALLEL-MONO:

OFF. 2) SET DUAL/MONO SWITCH TO
PARALLEL-MONO. 3) ADD JUMPER (14 GAGE

+

”

OR LARGER) ACROSS THE “

4) OUTPUT ACROSS CH-1 TERMINALS ONLY.

1) TURN AMPLIFIER

+

L. Level Controls

Each channel’s output level can be adjusted accu­rately using the 22 position detented level controls on
the back panel. A Lexan cover is also included that
can be used to prevent tampering (see Section 4.4).

M. Balanced Barrier Block Inputs

The

P.I.P.-BB

is included in the standard configuration.
It provides a balanced barrier block with three termi­nals for each input channel. (XLR connectors are also
available—see Section 8.1.)

N. Output Mode Switches

The output mode switches are used to configure each
channel independently for either 8/4 ohm loads or
70 volt (“constant voltage”) lines. WARNING: Do not

change these switches unless the amplifier is off. Do
not attempt to use the Bridge-Mono or Parallel-Mono
modes unless these switches are set the same. Also,

be sure to follow the special installation requirements
for each mode (see Section 3.3.1).

O. Output Barrier Block

A barrier block with four terminals is provided for out­put connection. Output wiring will vary depending on
the selected dual/mono mode and whether 70 volt out­put will be used (see Section 3.3.1).

70

VOLT

IMPORTANT:

CLASS 1 OUTPUT

WIRING REQUIRED.

” TERMINALS

Page 9

Com-Tech 200/400/800/1600 Power Amplifiers

3 Installation

This section covers basic
cedures. If your amplifier will be used in a Fire Protec­tive Signaling application, refer to Section 9 as well.

3.1 Mounting

Com-Tech

19 inch (48.3 cm) rack mounting or stacking without a
cabinet. In a rack, it is best to mount units directly on
top of each other. This provides the most efficient air
flow and support. If the rack will be transported, we
recommend that you fasten the amplifier’s back panel
securely to the rack to help support the unit’s weight.

All

Com-Tech

16 inches (40.6 cm) deep, and 0.25 inches (0.6 cm) in
front of the mounting surface. As you can see in Fig­ure 3.1,
mensions. Figure 3.1 labels the different heights as A,
B and C. These letters correspond to the list that fol­lows showing
mensions.

Height A: 3.5 inches (8.9 cm)

amplifiers are designed for standard

amplifiers are 19 inches (48.3 cm) wide,

Com-Tech

amplifiers vary in their vertical di-

Com-Tech

Models: Com-Tech 200 (All)

Com-Tech 400 (North American)

Com-Tech

installation pro-

models and their vertical di-

Height B: 5.25 inches (13.3 cm)

Models: Com-Tech 400 (100/120 VAC, 50/60 Hz)

Com-Tech 400 (220/240 VAC, 50/60 Hz)
Com-Tech 800 (All)

Height C: 7 inches (17.8 cm)

Model: Com-Tech 1600 (All)

3.2 Cooling

It is important to understand cooling considerations
when installing a
block the amplifier’s front or side air vents. This can
cause poor air flow and may result in overheating. If
the amplifier is rack-mounted, its sides should be at
least 2 inches (5 cm) away from the cabinet (see
Figure 3.2). Also, open spaces in the front of the rack
should be covered with blank panels to prevent
improper air flow. Otherwise, heated air from the side
exhaust vents can be drawn into the front air intake
which may greatly reduce the cooling system’s
effectiveness.

The real air flow requirement for a
depends on many things, but the most important factor
is average (RMS) output power. Air flow requirements
increase as output power increases, so anything that

Com-Tech

amplifier. First, never

Com-Tech

amplifier

Page 10

16 in

(40.6 cm

in

.5

: 3

)

A

m

R

E

W

O

E

L

B

A

N

E

P

E

D

O

C

IO

I

2

P

H

S

C

1

H

C

in

9

1

)

)

m

c

.3

8

(4

P

F

F

O

c

.9

(8

in

5

.2

)

: 5

m

B

c

.3

3

(1

in

: 7

)

C

m

c

.8

7

(1

Fig. 3.1 Mounting Dimensions

Com-Tech 200/400/800/1600 Power Amplifiers

17 in

43.2 cm

IMPORTANT: Be sure the back of

the amplifier is supported.

AIR

FLOW

16 in

40.6 cm

2 in

(5 cm)

MIN.

Fig. 3.2 Top View of a Rack-Mounted Unit

AMPLIFIER

(TOP VIEW)

AIR FLOW

AIR

FLOW

RACK

CABINET

affects output power also affects the required air flow.
Average output power is mainly affected by three

things: (1) duty cycle of the input signal, (2) load im­pedance, and (3) rated output power. First, as the duty
cycle of the input signal increases, the average output
power level increases. For example, the amplifier will
need more air flow with a rock ‘n’ roll input signal than
with infrequent paging. Second, as the load imped­ance of a connected loudspeaker gets smaller, more
current will flow across the load which effectively in­creases output power. This means you can expect the
amplifier to require more air flow with a 2 ohm load than
with a 4 ohm load. Finally, an amplifier that is rated for
higher power output is usually used at higher average
output levels. So a
put will require more air flow than a

Com-Tech 1600

delivering full out-

Com-Tech 200

These relationships and the resulting thermal dissipa­tion levels are defined mathematically in Section 7.

3.2.1 Cooling for Units without Internal Fans

All units have a three-speed on-demand cooling fan
except for the North American

Com-Tech 200

. Forced­air cooling may not be needed for applications with a
low duty cycle such as paging or background music.
This is why the North American

Com-Tech 200

is

usually provided without a fan.
If you will be using a North American

Com-Tech 200

in
a high temperature environment, or at full power for
sustained periods, you can anticipate that additional
cooling will be needed. It may also be helpful to use
the information in Section 7 to estimate the amplifier’s
thermal dissipation for your application. In general, a
North American

Com-Tech 200

that dissipates more

than 400 btu (100 kcal) per hour per unit will need ad­ditional cooling. If you want to test your amplifier for
sufficient cooling in the real world, an easy way is to
observe the

ODEP

indicators while the amplifier is op­erating under worst-case conditions. If the indicators
dim, additional cooling is recommended.

There are at least three ways to provide extra cooling
for an amplifier that does not have an internal fan. The
most effective method is to install an internal fan which
is available from Crown as an accessory (see Sec­tion 8.2). If you know in advance that an internal fan is
needed, you can order the

Com-Tech 200BF

cludes a factory-installed fan.
A rack-mounted blower or an air conditioner can also

be used to provide extra cooling. In some situations,
you may find it practical to use these methods without
installing a fan in each amplifier. However, we gener­ally recommend that you use the internal fans because
they provide the most efficient cooling, and are active
only when needed. Amplifiers that already have inter­nal fans can also take advantage of a rack-mounted
blower or air conditioner, so these approaches will be
discussed in the section that follows.

3.2.2 Additional Cooling for Units with Internal Fans

If multiple amplifiers will be operated under demand­ing conditions (such as driving loads less than
4 ohms), or if air flow through the rack will be restricted,
you should verify that the total air flow through the rack
will be sufficient. As described in Section 3.2.1, suffi­cient air flow can be tested in the real world by observ­ing the
worst-case conditions. If the indicators dim, cooling

.

can be improved by reducing air restrictions, installing

ODEP

indicators while operating under

a rack-mounted blower, or using an air conditioner.
Many things can cause air flow restrictions, including

improper mounting, bunched up power cords, closed
rack doors, and clogged dust filters. A

Com-Tech

plifier should be mounted in a way that allows sufficient
air flow into the front intakes, out the side exhaust
vents, and out the back of the rack. If your rack has a
front door, it is usually best to leave it open and avoid
blocking the air intakes. If this is impossible, supple­ment the air flow by mounting a grille in the door or with
a rack-mounted blower. If you install a grille in the door,
we recommend wire grilles over perforated panels be­cause wire tends to cause less air restriction (perfo­rated panels cause a minimum air restriction of 40%).

A better choice for increasing the air flow behind a
rack cabinet door is to use a “squirrel cage” blower.

which in-

am-

Page 11

Com-Tech 200/400/800/1600 Power Amplifiers

AIR

FLOW

AIR

FLOW

Fig. 3.3 Extra Cooling with a Rack-Mounted Blower

BLOWER

(OPTION 2)

EQUIPMENT

RACK

(SIDE VIEW)

BLOWER

(OPTION 1)

FRONT

OF

RACK

DOOR

Mount the blower at the bottom of the rack so it blows
outside air into the space between the door and the
front of the amplifiers, pressurizing the “chimney” be­hind the door (Figure 3.3, Option 1). The blower should
not blow air into or take air out of the space behind the
amplifiers. For racks without a front door, you can
evacuate the rack by mounting the blower at the top of
the rack, so that air blows out the back (Figure 3.3,
Option 2).

You can estimate the required air flow for a rack by
adding together the maximum required air flow ratings
of the individual units. The internal fan in a

200

(if installed),

400

and

800

can move up to 35 cu-

Com-Tech

bic feet (1 cubic meter) of air per minute, while the in­ternal fan in a

Com-Tech 1600

can move up to 65
cubic feet (1.8 cubic meters) per minute. If you
mounted one of each

Com-Tech

model in a rack,
worst-case conditions would require 170 cubic feet
(4.7 cubic meters) of air flow through the rack every
minute (3 x 35 cubic feet + 65 cubic feet = 170 cubic
feet).

Air flow restrictions may also result if the air filter be­comes clogged. If the air supply is unusually dusty,
you can help prevent rapid loading of the unit’s air filter
by pre-filtering the air using commercial furnace filters.
And when needed, the unit's filter can be cleaned with
mild dish detergent and water (see Section 4.5).

The final method for increased cooling is to use air
conditioning. Air conditioning is rarely a necessity be­cause internal fans and rack-mounted blowers almost
always provide enough air flow for even the most ex­treme conditions. Still, air conditioning can help by re-

ducing the temperature of the air circulated through
the rack. If you intend to install air conditioning for your
amplifiers, you may want to use Section 7 to determine
the hourly thermal dissipation of your system.

3.3 Wiring

Figures 3.4 through 3.7 show common ways to install a

Com-Tech

put terminals are located on the back panel. Please
use care when making connections, selecting signal
sources and controlling the output level. The load you
save may be your own! Crown assumes no liability for
damaged loads resulting from careless amplifier use
or deliberate overpowering.

CAUTION: Always disconnect the AC power and turn
the level controls off when making or breaking connec­tions. This is very important when loudspeakers are

connected because it reduces the chance of loud
blasts that can cause loudspeaker damage.

3.3.1 Mode of Operation

Proper wiring depends on how you configure your am­plifier. First, each output channel can be indepen­dently configured to drive step-down transformers in a
distributed “constant voltage” loudspeaker system
(70 volt mode) or loudspeakers that do not have step­down transformers (8/4 ohm mode). Second, the am­plifier can be configured for Dual, Bridge-Mono or
Parallel-Mono modes. Various combinations of these
modes are possible, so be sure to note any special
wiring requirements for the mode you will be using.

The 70 volt output mode is used to drive constant volt­age lines without expensive step-up transformers.
Avoiding the use of step-up transformers not only
saves money, but it also eliminates the distortion and
insertion loss caused by this type of transformer.

Setting up 70 volt mode is easy. Turn off the amplifier,
then slide the recessed output mode switches to the
right (as you face the back panel).

If Bridge-Mono mode is used with 70 volt output, the
amplifier will actually deliver 140 volts (more informa­tion is provided later in this section). To effectively use
this mode, you may need to cross-reference power rat­ings for the step-down transformer taps using Crown’s
constant voltage computer (see Section 8.3).

amplifier in a sound system. Input and out-

8/4

OHM

70

VOLT

7 0 V O L T

Page 12

Com-Tech 200/400/800/1600 Power Amplifiers

WARNING: The output mode switches must be set the
same (8/4 ohm or 70 volt mode) when operating in
Bridge-Mono or Parallel-Mono mode.

When connecting a 70 volt step-down transformer, do
not exceed its power rating. Too much power can
saturate a transformer and cause it to appear as a
short circuit to the amplifier. If this happens, no dam­age should occur, but the amplifier may run less effi­ciently.

8/4

OHM

70

VOLT

8 / 4 O H M

8/4 ohm mode is commonly used to drive loudspeak­ers with impedances from 2 to 16 ohms. When using
this output mode, appropriate load impedances will
depend on the dual/mono mode that you select. The
available dual/mono modes (Dual, Bridge-Mono and
Parallel-Mono) will be described in sections that follow.

Configuring your amplifier for 8/4 ohm mode is
straightforward. Turn off the amplifier, then slide the
output mode switches to the left (as you face the back
panel).

this, the input sensitivity should be set to 0.775 volts for
70 volt output (see Section 4.4). Again, you must al­ways configure both channels the same when using
Bridge-Mono or Parallel-Mono modes.

Because of the way

Com-Tech

amplifiers are de­signed, they can actually be used to directly drive con­stant voltage lines in 8/4 ohm mode. Being able to use
lower constant voltage levels can be very convenient if
building codes or other obstacles do not permit higher
constant voltage levels. When 8/4 ohm mode is used
to drive a distributed loudspeaker system, the constant
voltage output varies with the output power rating of
the amplifier. With 8/4 ohm output in Dual or Parallel­Mono mode, the
line, the

Com-Tech 400
Com-Tech 800
Com-Tech 1600

Com-Tech 200

can drive a 25 volt

can drive a 35 volt line, the

can drive a 50 volt line, and the

can drive a 70 volt line. Using Bridge­Mono mode, these voltage levels are doubled for a
single channel. Again, to effectively use different con­stant voltage levels, you may need to cross-reference
the ratings for the step-down transformers’ taps using
Crown’s constant voltage computer (see Section 8.3).

DUAL

PARALLEL

MONO

BRIDGE

MONO

When the amplifier is set up for two-channel (Dual
mode) operation, it is possible to configure one output
channel for 8/4 ohm operation and the other for 70 volt
operation. If you plan to use different output modes like

CHANNEL 1

CHANNEL 2

MIXER

CH-2 INPUT–+CH-1 INPUT

BB

Programmable
Input Processor (P.I.P.)

910

8

11

13

7

6

15

5

17

4

19

3

21

2

25

1

32

.5

0

dB

∞

CH-2 CH-1

TURN OFF THE AMP LIFIER

BRIDGE

MONO

THE DUAL/MONO SWITCH.

BEFORE CHANGING

Com-Tech Amplifier

DUAL 8/4 OHM MODE
(BOTH CHANNELS)

PARALLEL

MONO

PUSH TO RESET

R

P

R

E

S

E

S

T

E

S

DUAL

D U A L

Dual mode lets each amplifier channel work indepen­dently like a “dual mono” or stereo amplifier. And if you
select both Dual mode and 70 volt output, each output

70

8/4

OHM

CH2

–+

910

8

11

13

7

6

15

5

17

4

19

3

21

2

25

1

32

.5

0

dB

∞

8/4

VOLT

OHM

CH1

TURN OFF THE AMPLIFIER

70

VOLT

OUTPUT MODE SWITCHES.

CHANNEL 1

CHANNEL 2

BEFORE CHANGING THE

+

–

LOUDSPEAKERS

–

+

Fig. 3.4 Wiring for Dual 8/4 Ohm Mode

Page 13

Com-Tech 200/400/800/1600 Power Amplifiers

channel can be used to drive a 70 volt line. Installation
is intuitive: input channel 1 feeds output channel 1,
and input channel 2 feeds output channel 2.

To put the amplifier into Dual mode, turn it off, slide the
dual/mono switch to the center position, and properly
connect the output wiring. Be sure to observe correct
loudspeaker polarity (see Figure 3.4) and be careful
not to short the two outputs.

CAUTION: Never tie an amplifier’s outputs together di­rectly, and never parallel them with the output of an­other amplifier. Such connections do not result in

increased output power, but may cause overheating
and premature activation of the protection circuitry.

Note: To parallel multiple amplifiers for fail-safe redun­dancy, contact Crown’s Technical Support Group.

DUAL

PARALLEL

MONO

BRIDGE

MONO

B R I D G E - M O N O

Bridge-Mono mode is used to drive loads with a total
impedance of at least 4 ohms (see

Parallel-Mono

if the
load is less than 4 ohms). If Bridge-Mono mode and
70 volt output are used together, twice the normal out­put voltage is produced from a single channel to drive

140 volt distributed loudspeaker systems. If you will be
using 140 volt output, you may need to cross-refer­ence the ratings of the step-down transformer taps
with Crown’s constant voltage computer (see Section

8.3). If you need a single channel with higher power to
drive a 70 volt line, use Parallel-Mono mode.

WARNING: Both channels must be configured for the
same output mode (8/4 ohm or 70 volt) before switch­ing to Bridge-Mono mode.

Bridge-Mono wiring is very different from the other
modes and requires special attention. First, turn the
amplifier off. Then select Bridge-Mono mode by sliding
the dual/mono switch to the right (as you face the back
panel). Both outputs will receive the signal from chan­nel 1 with the output of channel 2 inverted so it can be
bridged with the channel 1 output. DO NOT USE THE
CHANNEL 2 INPUT or the signal level and quality may
be greatly degraded. Also, keep the channel 2 level
control turned down completely (counterclockwise).

Note: The channel 2 input jack and level control are not
defeated in Bridge-Mono mode. A signal feeding
channel 2 will work against the channel 1 signal, and
usually results in distortion and inefficient operation.

Connect the load across the two positive (+) output ter-

MIXER

Com-Tech Amplifier

DUAL 70 VOLT MODE
(BOTH CHANNELS)

Page 14

PARALLEL

MONO

PUSH TO RESET

R

P

R

E

E

S

S

S

T

E

CHANNEL 1

CHANNEL 2

DUAL

BB

Programmable
Input Processor (P.I.P.)

910

8

11

13

7

6

15

5

17

4

19

3

21

2

25

1

32

.5

0

dB

∞

CH-2 CH-1

TURN OFF THE AMPLIFIER

BRIDGE

MONO

THE DUAL/MONO SWITCH.

CH-2 INPUT–+CH-1 INPUT

–+

BEFORE CHANGING

8/4

OHM

CH2

910

8

11

13

7

6

15

5

17

4

19

3

21

2

25

1

32

.5

0

dB

∞

Fig. 3.5 Wiring for Dual 70 Volt Mode

70

8/4

VOLT

OHM

CH1

TURN OFF THE AMPLIFIER

70

BEFORE CHANGING THE

VOLT

OUTPUT MODE SWITCHES.

Use Dual 70 volt mode
for Fire Protective Sig­naling applications (see
Section 9).

+

–

LOUDSPEAKERS

–

+

CHANNEL 1

70 VOLT LINE

CHANNEL 2

+

COM

70 VOLT STEP-DOWN

TRANSFORMERS

COM

+

16, 8, OR 4 OHM

16, 8, OR 4 OHM

Com-Tech 200/400/800/1600 Power Amplifiers

COM

+

–

+

140 VOLT STEP-DOWN

TRANSFORMERS

16, 8, OR 4 OHM

16, 8, OR 4 OHM

140 VOLT LINE

MIXER

LOUDSPEAKERS

Com-Tech Amplifier

CHANNEL 1

BRIDGE-MONO
70 VOLT MODE
(140 VOLT OUTPUT)

TURN OFF THE AMPLIFIER

BEFORE CHANGING

THE DUAL/MONO SWITCH.

TURN OFF THE AMPLIFIER

BEFORE CHANGING THE

OUTPUT MODE SWITCHES.

WARNING: BOTH CHAN-

NELS MUST BE SET TO

70 VOLT MODE.

COM

+

–

+

DO NOT

USE

TURN OFF CHANNEL 2 (CCW)

IN BRIDGE-MONO MODE.

DO NOT USE

THE GROUND

TERMINALS

BRIDGE

MONO

DUAL

PARALLEL

MONO

BB

Programmable
Input Processor (P.I.P.)

–+

CH-2 INPUT–+CH-1 INPUT

70

VOLT

70

VOLT

8/4

OHM

8/4

OHM

CH1

CH2

CH-2 CH-1

0

dB

.5

1

2

3

4

5

6

7

8

910

11

13

15

17
19
21
25

32

∞

0

dB

.5

1

2

3

4

5

6

7

8

910

11

13

15

17
19
21
25

32

∞

P

R

E

S

S

R

E

S

E

T

PUSH TO RESET

minals (see Figure 3.6 and the middle illustration in
Figure 3.7). The positive lead from the load connects to
the positive channel 1 terminal, and the negative (or
ground) lead from the load connects to the positive
channel 2 terminal. Do not connect the output
grounds ( ). Also, the load must be balanced (neither
side shorted to ground).

CAUTION: Only connect balanced equipment (meters,
switches, etc.) to the Bridge-Mono output. Both sides of
the line must be isolated from the input grounds or os­cillations may occur.

DUAL

PARALLEL

MONO

BRIDGE

MONO

P A R A L L E L - M O N O

Parallel-Mono mode is used to drive loads with a total
impedance of less than 4 ohms when using 8/4 ohm
output mode (see

Bridge-Mono

if the load is greater

than 4 ohms). This mode can also be used to drive a

single high-powered 70 volt constant voltage line.
Parallel-Mono installation is very different from the

other modes and requires special attention.

WARNING: Both channels must be configured for the
same output mode (8/4 ohm or 70 volt) before switch­ing to Parallel-Mono mode.

To select Parallel-Mono mode, turn off the amplifier
and slide the dual/mono switch to the left (as you face
the back panel). Connect the input signal to channel 1
only. The channel 2 input jack and level control are by­passed in this mode, so they should not be used.

Note: It is normal for the channel 2 IOC indicator to stay
on in Parallel-Mono mode.

Connect the load to the channel 1 output as shown in
Figure 3.7 (top and bottom illustrations). The positive
lead from the load connects to the positive (+) terminal
of channel 1, and the negative (or ground) lead from
the load connects to the ground ( ) terminal of channel

1. Finally, install a jumper wire of at least 14 gauge be-

Fig. 3.6 Wiring for Bridge-Mono 70 Volt Mode (140 Volt Output)

Page 15