Crown Com-Tech CT-1600, Com-Tech CT-400, Com-Tech CT-200, Com-Tech CT-800, Com-Tech 200 Reference Manual

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Page 1

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

Com-Tech 200, 400, 800 & 1600

Some models may be exported under the name

Copyright ©1995 by Crown International, Inc., P.O. Box 1000, Elkhart, Indiana 46515-1000 U.S.A. Telephone: 219-294-8000. Com-Tech amplifiers are produced by the Professional Audio Division of Crown International, Inc. Trademark Notice:

™

bridge

are trademarks and and their respective owners.

TEF

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

Approved for THX Theatre

Systems

(CT-400 & 800)

American

120 VAC

North

Units:

Amcron

Models:

Crown

SmartAmp

,®

Techron

Commercial Audio E106377

,®

,™

MPX-6

,®

Com-Tech

,™

SMX-6

,®

IOC

,®

Fire Protective Signaling S5206

Amcron

,™

AMB-5

ODEP

™

and

,®

IQ System

Grounded

,®

P.I.P.

Commercial

Audio LL 32521C

K80636-2

3/95

Page 2

YEAR

THREE YEAR

FULL WARRANTY

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.

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: 219-294-8200. Facsimile: 219-294-8301

SUMMARY OF WARRANTY

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

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

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

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: 219-294-8200. 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

Page 3

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: 219-294-8200 Fax: 219-294-8301

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.

Page 4

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

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

Page 5

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

Page 6

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

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

Page 6

ODEP

IOC

SPI

CH1 CH2

ENABLE

POWER

OFF

Page 7

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

Page 8

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).

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).

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

400s

, and a 14 gauge cord with

1600s

. Other units have an ap-

POWER

OFF

Page 8

Page 9

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

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

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

CH-2 INPUT

910

∞

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).

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

17 19 21 25

∞

8/4

OHM

4 3 2

BRIDGE-MONO:

OFF. 2) SET DUAL/MONO SWITCH TO

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

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).

VOLT

IMPORTANT:

CLASS 1 OUTPUT

WIRING REQUIRED.

” TERMINALS

Page 9

Page 10

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

16 in

(40.6 cm

)

Page 10

Fig. 3.1 Mounting Dimensions

: 3

)

: 5

: 7

)

Page 11

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

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

Page 12

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

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

VOLT

7 0 V O L T

Page 12

Page 13

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

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

Programmable Input Processor (P.I.P.)

910

∞

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

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

8/4

OHM

CH2

–+

910

∞

8/4

VOLT

OHM

CH1

TURN OFF THE AMPLIFIER

VOLT

OUTPUT MODE SWITCHES.

CHANNEL 1

CHANNEL 2

BEFORE CHANGING THE

–

LOUDSPEAKERS

–

Fig. 3.4 Wiring for Dual 8/4 Ohm Mode

Page 13

Page 14

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

CHANNEL 1

CHANNEL 2

DUAL

Programmable Input Processor (P.I.P.)

910

∞

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

∞

Fig. 3.5 Wiring for Dual 70 Volt Mode

8/4

VOLT

OHM

CH1

TURN OFF THE AMPLIFIER

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

Page 15

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

COM

–

140 VOLT STEP-DOWN

TRANSFORMERS

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

Programmable Input Processor (P.I.P.)

–+

CH-2 INPUT–+CH-1 INPUT

VOLT

8/4

OHM

8/4

OHM

CH1

CH2

CH-2 CH-1

910

17 19 21 25

∞

910

17 19 21 25

∞

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

Page 16

MIXER

PARALLEL-MONO 70 VOLT MODE

Com-Tech Amplifier

MIXER

PARALLEL

MONO

PUSH TO RESET

CHANNEL 1

DUAL

NOT USED

CH-2 INPUT–+CH-1 INPUT

BRIDGE

MONO

Programmable Input Processor (P.I.P.)

–+

910

∞

CH-2 CH-1

CHANNEL 2 IS NOT USED

IN PARALLEL-MONO MODE.

TURN OFF THE AMPLIFIER

BEFORE CHANGING

THE DUAL/MONO SWITCH.

CHANNEL 1

DO NOT

USE

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

TURN OFF THE AMPLIFIER

BEFORE CHANGING THE

8/4 OHM

CH2

910

∞

8/4

VOLT

OHM

CH1

70 VOLT LINE

8/4

OHM

CH2

OUTPUT MODE SWITCHES.

VOLT

WARNING: BOTH CHAN-

8/4

VOLT

OHM

CH1

NELS MUST BE SET

TO 70 VOLT MODE.

ADD A 14 GAUGE OR

LARGER JUMPER

BETWEEN THE CHAN-

NEL 1 AND 2 POSI-

TIVE (+) TERMINALS.

COM

70 VOLT STEP-DOWN

TRANSFORMERS

COM

TURN OFF THE AMPLIFIER

BEFORE CHANGING THE

OUTPUT MODE SWITCHES.

VOLT

WARNING: BOTH CHAN-

NELS MUST BE SET TO

8/4 OHM MODE.

16, 8, OR 4 OHM

–

LOUDSPEAKERS

–

BRIDGE-MONO 8/4 OHM MODE

MIXER

PARALLEL-MONO 8/4 OHM MODE

Com-Tech Amplifier

PUSH TO RESET

PARALLEL

MONO

PUSH TO RESET

PARALLEL

MONO

CH-2 INPUT–+CH-1 INPUT

Programmable Input Processor (P.I.P.)

DUAL

BRIDGE

MONO

CHANNEL 1

Programmable Input Processor (P.I.P.)

–+

910

∞

CH-2 CH-1

TURN OFF CHANNEL 2 (CCW)

IN BRIDGE-MONO MODE.

TURN OFF THE AMPLIFIER

BEFORE CHANGING

THE DUAL/MONO SWITCH.

17 19 21 25

NOT USED

CH-2 INPUT–+CH-1 INPUT

–+

910

∞

CH-2 CH-1

17 19 21 25

910

∞

8/4

OHM

910

∞

6 5

4 3 2

DO NOT USE THE

OUTPUT GROUND

TERMINALS.

CH2

6 5

4 3 2

–

LOUDSPEAKER

TURN OFF THE AMPLIFIER

BEFORE CHANGING THE

8/4

VOLT

OHM

CH1

OUTPUT MODE SWITCHES.

VOLT

WARNING: BOTH CHAN-

NELS MUST BE SET

TO 8/4 OHM MODE.

ADD A 14 GAUGE OR

LARGER JUMPER

BETWEEN THE CHAN-

NEL 1 AND 2 POSI-

TIVE (+) TERMINALS.

DUAL

CHANNEL 2 IS NOT USED

IN PARALLEL-MONO MODE.

TURN OFF THE AMPLIFIER

BRIDGE

MONO

BEFORE CHANGING

THE DUAL/MONO SWITCH.

–

LOUDSPEAKER

Fig. 3.7 Wiring for Parallel-Mono 70 Volt, Bridge-Mono 8/4 Ohm and Parallel-Mono 8/4 Ohm Modes

Page 16

Page 17

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

tween the positive (+) terminals of both channels.

CAUTION: When Parallel-Mono wiring is installed, do not attempt to operate in Dual or Bridge-Mono mode until the wiring is removed (especially the jumper wire). Failure to do so will result in high distortion and excessive heating.

3.3.2 Input Connection

The balanced inputs have a nominal impedance of 20 K ohms (10 K ohms unbalanced) and will accept the line-level output of most devices. The factory-installed P.I.P.-BB provides a balanced three-terminal input barrier block for each channel (see Figure 2.2). Optional

P.I.P.

modules like the P.I.P.-FX, P.I.P.-FXQ and P.I.P.-FPX can provide female XLR connectors, phone jacks and phono (RCA) connectors. Various

P.I.P.s

are also available which provide a wide range

–

INPUT

–

INPUT

–

INPUT

Shield connected to both negative (–) and ground input terminals

–

INPUT

Twin-lead shielded cable

Floating

source

Output

Grounded

source

Output

Floating

source

Output

Grounded

source

Output

Shield connected to ground terminal

2-wire line cord

(or battery power)

Shield not connected at this end

3-wire grounded line cord

(or other ground connection)

2-wire line cord

(or battery power)

Single-conductor coax

3-wire grounded line cord

(or other ground connection)

Fig. 3.8 Unbalanced Input Wiring

Input ground terminal not used

Note: If two or more channels with

the same input ground reference

are driven from the same

Floating

source

floating source, connect

only one shield to the

source chassis.

INPUT

Output

–

2-wire line cord

(or battery power)

Grounded

source

Shield not connected at this end

INPUT

Output

–

3-wire grounded line cord

(or other ground connection)

Fig. 3.9 Balanced Input Wiring

of input signal processing features (see Section 8). Proper input wiring depends on two factors:

(1) whether the input signals are balanced or unbalanced, and (2) whether the signal source floats or has a ground reference. The following illustrations provide examples of recommended connection techniques for each type of signal source.

S O L V I N G I N P U T P R O B L E M S

–5

–10

1 f

–15

1 Hz 10 Hz 100 Hz 1 kHz 10 kHz

.1 f

.05 f

Fig. 3.10 Subsonic Filter Capacitor Values

Sometimes large subsonic (subaudible) frequencies are present in the input signal. These can damage loudspeakers or step-down transformers by overloading or overheating them. To attenuate such frequencies, place a capacitor in series with the input signal line. The graph in Figure 3.10 shows some capacitor values and how they affect frequency response. Use

or twisted pair

only low-leakage capacitors. Another problem to avoid is large levels of radio fre-

quencies or RF in the input signal. Although high RF levels may not pose a threat to the amplifier, they can burn out tweeters or other loads that are sensitive to

.01 f

Frequency

–

Page 17

Page 18

1.8 K

Ω

Source

600

Source

600

Source

Note: A low source impedance (R) can be

increased to 600 by an appropriate resistor.

.003

3.9 mH

.015

Ω

5 mH

.018

Ω

Amp

fµ

GND

Amp

GND

Amp

fµ

GND

4 kHz 10 kHz 40 kHz 100 kHz

12 dB/octave

Frequency

6 dB/octave

Fig. 3.11 Unbalanced RFI Filters

high frequencies. Extremely high RF levels can also cause your amplifier to prematurely activate its protection circuitry, resulting in inefficient operation. RF can be introduced into a signal by local radio stations and

0.47 Film

910Ω

1.8 mH

2.5 mH

1.8 mH

.003

.015

.018

.015

fµ

Balanced Out

–

fµ

Balanced Out

–

fµ

Balanced Out

–

fµ

Balanced Out

–

Balanced In

–

Balanced In

–

Balanced In

–

Balanced In

–

Fig. 3.12 Balanced RFI Filters

from the bias signal of many tape recorders. To prevent high levels of input RF, install an appropriate lowpass filter in series with the input signal. Some examples of unbalanced wiring for low-pass filters are shown in Figure 3.11.

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

Input Wiring Tips

1. Use only shielded cable. Cables with

–10

higher density shields are better. Spiral wrapped shield is not recommended.

–20

2. When using unbalanced lines, keep the cables as short as possible. Avoid cable lengths greater than 10 feet (3 meters).

3. Do not run signal cables together with high-level wiring such as loudspeaker wires or AC cords. This reduces the chance of hum or noise being induced into the input cables.

4. Turn the entire system off before changing connections. Turn level controls down before powering the system back up. Crown is not liable for damage incurred when any transducer or component is overdriven.

Tip:

The standard

P.I.P.-BB

has plenty of space on its

circuit board for the addition of input filter circuitry. Another problem to avoid is ground loops. These are

undesirable currents that flow in a grounded system and usually cause hum in the output. A common source of ground loop problems is the placement of input cables parallel to power cables or near power transformers. A ground loop can occur when the magnetic field generated by the 50/60 Hz alternating current in the power cable or transformer is induced into the input cables. To prevent this, you can lace the input cables along their length. (Lacing cables helps reduce magnetically induced current by minimizing the cross-sectional area between conductors which could bisect a magnetic field.) It is also very important to locate input cables away from power cables and transformers.

Ground loops often occur when the input and output grounds are tied together. DO NOT CONNECT THE INPUT AND OUTPUT GROUNDS TOGETHER. Tying the grounds together can also cause feedback oscilla- tion from the load current flowing in the loop. To avoid this problem, use proper grounding, isolate the inputs, and isolate other common AC devices.

For balanced input wiring, use an example from Figure

3.12. Filters A, B, and C correspond to the unbalanced filters shown in Figure 3.11. Filter D also incorporates the subsonic filter in Figure 3.10.

Page 18

3.3.3 Output Connection

Consider the power handling capacity of your load before connecting it to the amplifier. Crown is not liable for damage incurred at any time due to overpowering. Fusing loudspeaker lines is highly recommended (see Section 3.3.4). Also, please pay close attention to Sec-

Page 19

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

Use Good Connectors

1. To prevent possible short circuits, do not expose the loudspeaker cable connectors.

2. Do not use connectors that might accidentally tie two channels together when making or breaking connections (for example, a standard three-wire stereo phone plug).

3. Connectors that can be plugged into AC power receptacles should never be used.

4. Connectors with low current-carrying capacity should not be used.

5. Connectors with any tendency to short should never be used.

tion 4.1, You should always install loudspeaker cables of suffi-

cient gauge (wire thickness) for the length used. The resistance introduced by inadequate output cables will reduce the amplifier’s power to and motion control of the loudspeakers. The latter problem occurs because the damping factor decreases as the cable resistance increases. This is very important because the amplifier’s excellent damping factor can be easily negated by using insufficient cable.

Use the nomograph in Figure 3.13 and the following procedure to find the recommended wire gauge (AWG or American Wire Gauge) for your system.

1. Note the load resistance of the loudspeakers connected to each channel of the amplifier. If you are using 70 volt output, be sure to determine the load resistance of the step-down transformers (Crown’s constant voltage computer can help with this, see Section 8.3). Mark this value on the “Load Resistance” line of the nomograph.

2. Select an acceptable damping factor and mark it on the “Damping Factor” line. Your amplifier can provide an excellent damping factor of 1,000 from 10 to 400 Hz in Stereo mode with an 8 ohm load. In contrast, typical damping factors are 50 or lower. Higher damping factors yield lower distortion and greater motion control over the loudspeakers. A common damping factor for commercial applications is between 50 and 100. Higher damping factors may be desirable for live sound, but long cable lengths often limit the highest damping factor that can be achieved practically. (Under these circumstances, Crown’s ily monitored and controlled when they are located very near the loudspeakers.) In recording studios and home hi-fi, a damping factor of 500 or more is very desirable.

Precautions

IQ System

is often used so amplifiers can be eas-

.0002

SOURCE

RESISTANCE

(ohms)

.0004

.0006

.001

1.5

0.9

0.8

0.7

0.6

0.5

LOAD

RESISTANCE

(ohms)

DAMPING

FACTOR

20,000

10,000

5,000

2,000

1,000

500

200

100

Example Shown:

R = 8 ohms; R = 0.016 ohms or D.F. = 500;

Cable Length = 10 ft.; answer: #8 wire

.002

.004

.006

.01

.02

ANNEALED

2-COND.

CABLE

(feet)

1 2

5 10 20

100 200

500 1000 2000

5000

(ohms/1000 ft.)

8000 5000

1000

COPPER

WIRE

(AWG)

500

#28

100

#26

#24 #22 #20 #18

#16 #14

#12 #10 #8

#6 #4

#2 #0 #00

#0000

.05

.01

.04

.06

Fig. 3.13 Wire Size Nomograph

3. Draw a line through the two points with a pencil, and continue until it intersects the “Source Resistance” line.

4. On the “2-Cond. Cable” line, mark the length of the cable run.

5. Draw a pencil line from the mark on the “Source Resistance” line through the mark on the “2-Cond. Cable” line, and on to intersect the “Annealed Copper Wire” line.

6. The required wire gauge for the selected wire length and

Page 19

Page 20

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

damping factor is the value on the “Annealed Copper Wire”

Note: Wire size increases as the AWG gets smaller

line.

7. If the size of the cable exceeds what you want to use, (1) find a way to use shorter cables, like using the

IQ System

(2) settle for a lower damping factor, or (3) use more than one cable for each line. Options 1 and 2 will require the substitution of new values for cable length or damping factor in the nomograph. For option 3, estimate the effective wire gauge by subtracting 3 from the apparent wire gauge every time the number of conductors of equal gauge is doubled. So, if #10 wire is too large, two #13 wires can be substituted, or four #16 wires can be used for the same effect.

SOLVING OUTPUT PROBLEMS

High-frequency oscillations can cause your amplifier

to prematurely activate its protection circuitry. The effects of this problem are similar to the RF pr oblems described in Section 3.3.2. T o prevent high-frequency oscillations, follow these guidelines:

1. Bundle together each pair of loudspeaker conductors when using long cable runs or when different amplifiers use a common cable tray or jacket. (Do NOT bundle wires from different amplifiers.) This reduces the chance of conductors acting like antennas to transmit or receive the high frequencies that can cause oscillation.

2. Avoid using shielded loudspeaker cable.

3. Never tie together input and output grounds.

4. Never tie together the output of different amplifiers.

5. Keep output cables separated from input cables.

6. Install a low-pass filter in series with each input (see Section 3.3.2).

7. Install the input wiring according to the instructions in Section 3.3.2.

Another problem to avoid is the presence of large sub- sonic currents when primarily inductive loads are used. Examples of inductive loads are 70 volt transformers and electrostatic loudspeakers.

Inductive loads can appear as a short circuit at low frequencies. This can cause the amplifier to produce

4 ohm, 20 watt

Resistor

From

Amplifier

Output

–

590 to 708 µf Capacitor

120 VAC, N.P.

Inductive

Load

–

large low-frequency currents and activate its protection circuitry. Always take the precaution of installing a high-pass filter in series with the amplifier’s input when inductive loads are used. A three-pole, 18 dB per oc-

tave filter with a –3 dB frequency of 50 Hz is recommended (some applications may benefit from an even higher –3 dB frequency). Such a filter is described with subsonic frequency problems in Section 3.3.2.

Another way to protect inductive loads from large lowfrequency currents and prevent the amplifier from prematurely activating its protective systems is to parallel a 590 to 708 µF nonpolarized motor start capacitor and a 4 ohm, 20 watt resistor in series with the amplifier output and the positive (+) transformer lead. This circuit is shown in Figure 3.14. It uses components that are available from most electrical supply stores.

3.3.4 Additional Load Protection

Com-Tech

amplifiers can generate enormous power output. Using 8/4 ohm output, if your loudspeakers do not have built-in protection from excessive power, it’s a good idea to protect them. Loudspeakers are subject to thermal damage from sustained overpowering and

1.0

1.2

1.4

1.6

2.5

14 16

Example: Z = 8 ohms.

Peak Power = 75 W

Answer: Fuse = 1.5 A

(ohms)

SPEAKER Z

FUSE

(amps)

6 5

1.5

.6 .5 .4

.15

.08

SPEAKER RATING

3000

2000

1500 1000

800 600

400 300

200

150 100

80 60

40 30

(Typically 4 times the continuous average power)

8 6

(watts)

PEAK MUSIC POWER

1.5 1

Page 20

Fig. 3.15 Loudspeaker Fuse NomographFig. 3.14 Inductive Load (Transformer) Network

Page 21

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

mechanical damage from large transient voltages. In both cases, special fuses may be used to protect your loudspeakers, or you may opt for the convenience of a

P.I.P.

module that provides loudspeaker protection.

Two different types of fuses are required for thermal protection and voltage protection. Slow-blow fuses are usually selected to protect loudspeakers from thermal damage because they are similar to loudspeakers in the way they respond to thermal conditions over time. In contrast, high-speed instrument fuses like the Littlefuse 361000 series are used to protect loudspeakers from large transient voltages. The nomograph in Figure 3.15 can be used to select the properly rated fuse for either type of loudspeaker protection.

There are mainly two different approaches used when installing fuses for loudspeaker protection. A common practice is to put a single fuse in series with the output of each channel. This makes installation easy because there is only one fuse per channel to install, but it can also lead to problems. The biggest disadvantage becomes apparent if the fuse blows because power to all connected loads will be removed.

A better approach is to fuse each driver independently. This allows you to apply the most appropriate protection for the type of driver being used. In general, low-frequency drivers (woofers) are most susceptible to thermal damage and high-frequency drivers (tweeters) are usually damaged by large transient voltages.

This means that your loudspeakers will tend to have better protection when the woofers are protected by slow-blow fuses and high-frequency drivers are protected by high-speed instrument fuses.

Depending on the application, you may want to use a

P.I.P.

module to protect your loudspeakers. When properly configured, all driven compression can provide loudspeaker protection. Some of the compression include the P.I.P.-AMCb, P.I.P.-EDCb and P.I.P.-PA. While the P.I.P.-EDCb is most commonly used for general loudspeaker protection, the P.I.P.AMCb is very popular in systems that require a highquality crossover, and the P.I.P.-PA is the processor of choice for applications that require a microphone and line level input for each channel. For more information on

P.I.P.

modules, see Section 8.

P.I.P.

modules with signal-

P.I.P.

modules with signal-driven

3.4 AC Mains Power

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

200s

and

400s

, and a 14 gauge cord with

800s

and

1600s

. Other

nished with an appropriate AC cord and plug. Use an isolated wall outlet whenever possible with the

correct voltage and adequate current. Voltages greater than 10% above the specified AC mains voltage for the amplifier may damage the ±15 volt regulator, filter capacitors and output transistors. See Section 7 for power requirements under various conditions.

Com-Tech

amplifiers are fur-

Com-Tech Com-Tech

All specifications in this manual were measured using 120 VAC, 60 Hz power mains unless otherwise noted. Specifications are derived using a mains voltage that is accurate to within 0.5% with THD less than 1.0% under all testing conditions. Performance variations can occur at other AC voltages and line frequencies. In addition, line regulation problems will directly affect the output power available from the amplifier.

Page 21

Page 22

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

4 Operation

4.1 Precautions

Although your amplifier is protected from internal and external faults, you should still take the following precautions for optimum performance and safety:

1. Improper wiring for the Dual, Bridge-Mono and Parallel-Mono modes, as well as the 8/4 ohm and 70 volt output modes can result in serious operating difficulties. Refer to Section 3.3.1 for details.

2. WARNING: Never attempt to operate the amplifier in either Bridge-Mono or Parallel-Mono mode unless both output channels are configured the same (8/4 ohm or 70 volt).

3. When driving an inductive load (like a 70 volt stepdown transformer) use a high-pass filter or protective network to prevent premature activation of the amplifier’s protection circuitry (see Section 3.3.3).

4. WARNING: Do not change the position of the dual/ mono switch or the output mode switches unless the amplifier is first turned off.

5. CAUTION: In Parallel-Mono mode, a jumper must be installed between the channel 1 and 2 positive (+) output terminals. Be sure to remove this jumper for Dual or Bridge-Mono modes, otherwise high distortion and excessive heating will occur. Check the

dual/mono switch on the back panel for proper position.

6. Turn off the amplifier and unplug it from the AC mains before removing a dust filter.

7. Use care when making connections, selecting signal sources and controlling the output level. The load you save may be your own!

8. Do not short the ground lead of an output cable to the input signal ground. This may form a ground loop and cause oscillations.

9. Operate the amplifier from AC mains of not more than 10% above or below the selected line voltage and only the specified line frequency.

10. Never connect the output to a power supply output, battery or power main. Such connections may result

in electrical shock.

11. Tampering with the circuitry by unqualified personnel, or making unauthorized circuit changes may be hazardous and invalidates all agency listings.

Remember: Crown is not liable for damage that results from overdriving other system components.

P.I.P.

card or before removing the

4.2 Indicators

The front panel of a helpful indicators. The amber Enable indicator is pro- vided to show the amplifier has been turned on (or enabled) and that its low-voltage power supply is working. It does not indicate the status of the high-voltage power supplies. For example, the Enable indicator will remain lit in the unlikely event that one of the amplifier’s protection systems (described in Section 4.3) removes power from one (or both) high-voltage supplies to put the channel in “standby” mode. The Enable indicator will be illuminated for all conditions shown in Figure 4.1 except for the first example, “There is no power to the amplifier.”

The green tion of Crown’s patented Output Device Emulation Protection circuitry. During normal operation, they glow brightly to confirm the presence of reserve thermal-dynamic energy. They dim proportionally as the energy reserve decreases. In the rare event that there is no reserve, the indicators will turn off and portionally limit the drive level of the output stages so the amplifier can continue safe operation even when conditions are severe. (For a more detailed description of

ODEP

A channel’s voltage power supply is put in “standby” mode or the amplifier’s circuit breaker is tripped. The standby mode is activated if DC or heavy common-mode current is detected at the output, if the transformer thermal protection system is activated, or if a P.I.P.-UL1711 or the IQ-P.I.P. is used to shut down a high-voltage power supply. (For more information, see Section 4.3.3 and the table in Figure 4.1.)

The yellow meters to provide The pares the incoming signal’s waveform to that of the output. Any difference between the two is distortion. The

0.05% or more. It is normal for them to light momentarily when the amplifier is first turned on.

ODEP

, see Section 4.3.1.)

ODEP

IOC

(Input/Output Comparator) circuitry com-

IOC

indicators flash if there is a difference of

channel 2 IOC indicator will stay on in Parallel-Mono mode.

The green Signal Presence Indicators (SPI) flash syn- chronously with the output audio. The SPI detector circuit is connected in the signal path after the input gain stages and level controls, so a flashing indicator tells you that there is audio in and out of the amplifier.

The Signal Presence Indicators may not report signal presence if the output signal level is too low.

Com-Tech

indicators confirm the normal opera-

indicator also turns off if its high-

indicators act as sensitive distortion

amplifier has several

ODEP

will pro-

P.I.P.

like the

proof of distortion-free performance

Note: the

Note:

Page 22

Page 23

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

Indicator Status Amplifier Condition

ODEP

IOC

SPI

ODEP

IOC

SPI

ODEP

IOC

SPI

ODEP

IOC

SPI

ODEP

IOC

SPI

ODEP

IOC

SPI

OFF OFF OFF

ON OFF OFF

OFF ON OFF

OFF OFF Active

ON ON OFF

ON OFF Active

There is no power to the amplifier. Possible reasons: (1) The amplifier’s Enable switch is off. (2) The amplifier is not plugged into the power receptacle. (3) The AC mains circuit breaker has been tripped. (4) The amplifier’s back panel circuit breaker has been tripped. (5) The amplifier’s low-voltage power supply fuse has blown.

Normal operation for a channel with NO output. Possible reasons: (1) There is no input signal. (2) The channel’s level control is turned down.

No output: The amplifier channel is in standby mode. Possible reasons: (1) The amplifier has just been turned on and is still in the four second turn-on delay. (2) A P.I.P. module such as an IQ-P.I.P. or the P.I.P.-UL1711 has turned off the channel’s high-voltage supply.

ODEP limiting is about to begin. Possible reasons: (1) The amplifier’s air filters are blocked and need to be cleaned. (2) There is insufficient cooling because of inadequate air flow or air that is too hot. (3) The load impedance for the channel is too low because the output is shorted or the amplifier is driving too many loudspeakers for the selected dual/mono mode. (4) The amplifier channel is continuously being driven to very high output levels.

No output: The amplifier channel is in standby mode. Possible reasons: (1) The DC/low-frequency protection circuitry has been activated. (2) The fault protection circuitry has been activated after sensing heavy common-mode current. (3) The transformer thermal protection circuitry has been activated.

Channel 2 only: The amplifier is in Parallel-Mono mode with no output. The channel 2 IOC indicator always turns on when the amplifier’s dual/mono switch is moved to the Parallel-Mono position.

Normal operation with an input signal. The signal presence indicator (SPI) will flash to show that an audio signal is present.

ODEP

IOC

SPI

ODEP

IOC

SPI

OFF ON Active

ON ON Active

ODEP limiting has been activated. Possible reasons: (1) The amplifier’s air filters are blocked and need to be cleaned. (2) There is insufficient cooling because of inadequate air flow or air that is too hot. (3) The load impedance for the channel is too low because the output is shorted or the amplifier is driving too many loudspeakers for the selected dual/mono mode. (4) The amplifier channel is continuously being driven to very high output levels.

The channel’s output is exceeding 0.05% distortion. The input signal level is too high, and IOC is reporting either an input overload or output clipping.

Channel 2 only: The amplifier is in Parallel-Mono mode and has output. The channel 2 IOC indicator always turns on when the amplifier’s dual/mono switch is moved to the Parallel-Mono position.

Fig. 4.1 ODEP, IOC and Signal Presence Indicator States

4.3 Protection Systems

Com-Tech

diagnostics capabilities. Protection systems include

ODEP

features provide protection under any conditions.

4.3.1

Crown invented problems in amplifier design: to prevent amplifier shutdown during demanding operation, and to increase the efficiency of the output circuitry.

amplifiers provide extensive protection and

, “standby” and an AC circuit breaker. These

ODEP

to solve two long-standing

To do this, Crown established a rigorous program to measure the

safe operating area

(SOA) of each output device before installing it in an amplifier. Next, Crown designed intelligent circuitry to simulate the instantaneous operating conditions of the output devices. Its name describes what it does: Output Device Emula-

ODEP

tion Protection or

. In addition to simulating the operating conditions of the output devices, it also compares their operation to their known SOA. If

ODEP

sees that more power is about to be asked of the output devices than they are capable of delivering under the

Page 23

Page 24

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

present conditions,

ODEP

immediately limits the drive level until it falls within the SOA. Limiting is proportional and kept to an absolute minimum—only what is required to prevent output device damage.

This level of protection enables Crown to increase output efficiency to never-before-achieved levels while greatly increasing amplifier reliability.

The on-board intelligence is monitored in two ways. First, the front panel the amplifier is functioning correctly or if ing the drive level. Second, connector inside the amplifier’s back panel partment so advanced

ODEP

indicators show whether

ODEP

data is fed to the

P.I.P.

modules like the IQ-P.I.P.

ODEP

P.I.P.

is limit-

com-

can use it to monitor and control the amplifier. This is how

ODEP

keeps the show going with maxi-

mum power and maximum protection at all times.

4.3.2 Standby Mode

An important part of a

Com-Tech

amplifier’s protection systems is standby mode. Standby protects the amplifier during potentially catastrophic conditions. It temporarily removes power from the high-voltage supplies to protect the amplifier and its loads. Standby mode can be identified using the indicator table in Figure 4.1.

When you turn on the Enable switch, standby mode is activated to provide turn-on protection. This power-up delay lets other system components settle before any signals are amplified, and it provides some “randomness” to the power-up sequence of multiple units which reduces the system’s current demand during start-up.

If dangerous subsonic frequencies or direct current (DC) is detected in the amplifier’s output, the unit will activate its DC /low-frequency protection circuitry and put the affected channels in standby. This protects the loads and prevents oscillations. The unit resumes normal operation as soon as the amplifier no longer detects dangerous low-frequency or DC output. Although it is extremely unlikely that you will ever activate the amplifier’s DC /low-frequency protection system, improper source materials such as subsonic square waves or input overloads that result in excessively clipped input signals can activate this system.

The amplifier’s fault protection system will put an amplifier channel into standby mode in rare situations where heavy common-mode current is detected in a channel’s output. The amplifier should never output heavy common-mode current unless its circuitry is damaged in some way, and putting the channel in

standby mode helps to prevent further damage. The amplifier’s transformer thermal protection circuitry

is activated in very unusual circumstances where the unit’s transformer temperature rises to unsafe levels. Under these abnormal conditions, the amplifier will put both channels into standby mode. In addition, the cooling fan will run at full speed. The amplifier will return to normal operation after the transformer cools to a safe temperature. (For more information on transformer thermal protection, refer to the section that follows.)

4.3.3 Transformer Thermal Protection

All

Com-Tech

amplifiers have transformer thermal protection which protects the power supplies from damage under rare conditions where the transformer temperature rises too high. A thermal switch embedded in the power transformer removes power to the high-voltage power supplies if it detects excessive heat. The switch automatically resets itself as soon as the transformer cools to a safe temperature.

If your amplifier is operated within rated conditions, it is extremely unlikely that you will ever see it activate transformer thermal protection. One reason is that

ODEP

keeps the amplifier working under very severe conditions. Even so, higher than rated output levels, excessively low-impedance loads and unreasonably high input signals can generate more heat in the transformer than in the output devices. This can overheat the transformer and activate its protection system.

Com-Tech

amplifiers are designed to keep working under conditions where other amplifiers would fail. But even when the limits of a

Com-Tech

are exceeded, it still

protects itself—and your investment—from damage.

4.3.4 Circuit Breaker

A circuit breaker is provided to prevent excessive current draw by the high-voltage power supplies. A reset switch for the circuit breaker is provided on the back panel. The rating of the circuit breaker for each amplifier model and each AC mains voltage is provided with the specifications in Section 6. When operating with rated loads and output levels, this breaker should only trip in the incredibly rare instance of a catastrophic amplifier failure. Other protection systems such as

ODEP

keep the amplifier safe and operational under most other severe conditions. The breaker can also trip in situations where extremely low-impedance loads and high output levels result in current draw that exceeds the breaker’s rating. Again, this should only be possible when operating

outside rated conditions

Page 24

Page 25

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

like when the amplifier is used to drive a 1 ohm load, or when an input signal is clipped severely.

4.4 Controls

The Enable switch is located on the front panel so you can easily turn the amplifier on and off. If you ever need to make any wiring or installation changes, don’t forget to disconnect the power cord. Please follow these steps when first turning on your amplifier:

1. Turn down the level of your audio source. For example, set your mixer’s volume to –.

2. Turn down the level controls of the amplifier.

3. Turn on the Enable switch. The Enable indicator beside the switch should glow. During the four second turn-on delay which immediately follows, the indicators will flash as described in Figure 4.1.

ODEP

After the delay, the on with full brilliance and the Presence Indicators should function normally.

4. After the turn-on delay, turn up the level of your audio source to the maximum desired level.

5. Turn up the level controls on the back panel of the amplifier until the maximum desired loudness or power level is achieved.

6. Turn down the level of your audio source to its

normal range.

A 22-position detented level control is provided for each channel. For security, the level controls are located on the back panel. To prevent tampering from the rear, a Lexan cover is provided that can be attached to the back panel with the included 1¦2" 8-32 screws.

Com-Tech

amplifiers have a back panel reset switch for the AC mains circuit breaker. If the circuit breaker trips for some reason, the Enable indicator will turn off. In this situation, turn off the Enable switch and reset the circuit breaker. Then turn the Enable switch back on. If the breaker trips again or if the unit fails to operate properly, contact an authorized service center or Crown’s Technical Support Group.

A three-position input sensitivity switch is located inside the amplifier’s

P.I.P.

factory to a sensitivity of 0.775 volts (8/4 ohm mode). Please notice that there is a separate 0.775 volt position for 70 volt mode. If desired, the sensitivity can be switched to a voltage gain of 26 dB. With 26 dB gain and 70 volt output, the input sensitivity for all models is

3.5 volts. With 26 dB gain and 8/4 ohm output, the input sensitivity varies among the different amplifier

indicators should come

compartment. It is set at the

IOC

and Signal

SENSITIVITY SWITCH INSIDE ACCESS HOLE

sen

itiv

ity

26 dB

ain

0.77

sensitivity

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

910

17 19 21 25

∞

CH-2 CH-1INPUT ATTENUATION

8/4 ohm

910

17 19 21 25

∞

Fig. 4.2 Input Sensitivity Switch

models. To generate standard 1 kHz power, the input voltage required is 1.48 volts for the

2.12 volts for the

Com-Tech 800

Com-Tech 400

and 3.29 volts for the

Com-Tech 200

, 2.47 volts for the

Com-Tech 1600

It is also possible to configure the amplifier with one channel set to 8/4 ohm output and the other set to 70 volt. With this configuration, the input sensitivity switch should be set to 0.775 volts (70 volt), and the level control for the 8/4 ohm channel can be adjusted to compensate for the additional gain.

To change the input sensitivity:

1. Turn off the amplifier and disconnect the power cord from the receptacle.

2. Remove the

P.I.P.

module.

3. Locate the access hole for the sensitivity switch inside the chassis opening (Figure 4.2).

Note: The sensitivity switch will not be visible because it is mounted below the hole. Use your little finger to reach it.

4. Set the switch to the desired position noted on the access hole label.

5. Replace the

P.I.P.

module and restore power.

4.5 Filter Cleaning

A dust filter is provided on the amplifier’s air intake (Figure 2.1). If this filter becomes clogged, the unit will not cool as efficiently as it should and high heat sink temperatures may produce lower-than-normal output.

To clean the filter, use a phillips screwdriver to remove the screws that hold the front panel grille in place. Use mild dishwashing detergent and warm water for best cleaning results. Replacement filters may be ordered from the factory.

Dust filters are not 100% efficient—long term this may require internal heat sink cleaning by a qualified technician. Internal cleaning information is available from our Technical Support Group.

Page 25

, .

Page 26

5 Technical Information

5.1 Overview

Com-Tech

logical advancements including real-time computer simulation, low-stress output stages, an advanced heat sink embodiment and the Programmable Input Processor (

Custom circuitry is incorporated to limit temperature and current to safe levels making it highly reliable and tolerant of faults. Unlike many lesser amplifiers, it can operate at its voltage and current limits without self-destructing.

Real-time computer simulation is used to create an analogue of the junction temperature of the output transistors (hereafter referred to as the output devices). Current is limited only when the device temperature becomes excessive (and by the minimum amount required). This patented approach called Output Device Emulation Protection (or the available output power and protects against overheating—the major cause of device failure.

The amplifier is protected from all common hazards that plague high-power amplifiers, including shorted, open or mismatched loads; overloaded power supplies, excessive temperature and chain-destruction phenomenon; input overload, high-frequency blowups, internal faults, and input and output DC.

The four-quadrant topology used in a amplifier’s output stages is called the

bridge

power supply providing peak-to-peak voltages to the load that are twice the voltage seen by the output devices (see Figure 5.1).

As its name suggests, the is referenced to ground. Composite devices are constructed to function as gigantic NPN and PNP devices to handle currents which exceed the limits of available devices. Each output stage has two composite NPN devices and two composite PNP devices.

The devices connected to the load are referred to as “high-side NPN and PNP” and the devices connected to ground are referred to as “low-side NPN and PNP.” Positive current is delivered to the load by increasing conductance simultaneously in the high-side NPN and low-side PNP stage, while synchronously decreasing conductance of the high-side PNP and low-side NPN.

The two channels may be used together to double the voltage (Bridge-Mono) or current (Parallel-Mono) pre-

amplifiers incorporate several new techno-

P.I.P.

) expansion system.

ODEP

) maximizes

Com-Tech

grounded

. This patented topology makes full use of the

grounded bridge

topology

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

sented to the load. This feature gives you flexibility to maximize power available to the load.

A wide bandwidth, multiloop design is used for stateof-the-art compensation. This produces ideal behavior and results in ultra-low distortion values.

Aluminum extrusions have been widely used for heat sinks in power amplifiers due to their low cost and reasonable performance. However, measured on a watts per pound or watts per volume basis, the extrusion technology doesn’t perform nearly as well as the heat sink technology developed for

Our heat sinks are fabricated from custom convoluted fin stock that provides an extremely high ratio of area to volume, or area to weight. All power devices are mounted directly to massive heat spreaders that are electrically at the Vcc potential. Electrifying the heat spreaders improves thermal performance by eliminating the insulating interface underneath each power device. The chassis itself is used as part of the thermal circuit to maximize utilization of the available cooling resources.

Com-Tech

amplifiers.

5.2 Circuit Theory

Each channel is powered by its own power transformer winding. Both channels share a common low-voltage supply. The secondary output of T100 is full-wave rectified by D109 and is filtered by a large computer grade capacitor. A thermal switch embedded in the power transformer protects it from overheating.

The low-voltage winding of the transformer is rectified by diodes D1, D2, D3 and D4 to generate an unregulated 24 volts. Monolithic regulators U1 and U2 provide a regulated ±15 volts.

5.2.1 Dual Operation

For simplicity, the discussion of Dual operation will refer to one channel only. Mono operation will be discussed in Sections 5.2.2 and 5.2.3.

Please refer to the block diagram in Figure 5.1 and the schematics provided at the back of this manual.

The signal at the into the balanced input stage (U104-A). The balanced input stage causes balanced to single-ended conversion using a difference amplifier. Next the variable gain stage (U104-B) amplifies or attenuates the signal. The gain of this stage is set by the position of the input sen-

P.I.P.

barrier block passes directly

Page 26

Page 27

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

+Vcc

(ODEP)

OUTPUT

NPN LOW

NPN HI

OUTPUT

+Vcc

+24

ENABLE

+Vcc

STAGE

SUPPLY

POWER

DC/LF

TIMER

FAULT

POWER

SUPPLY

CONTROL

–Vcc

BRIDGE

BALANCE

BIAS

(DISPLAY)

(ODEP)

OUTPUT

(DISPLAY)

–Vcc

–24

OUTPUT

PNP LOW

PNP HI

OUTPUT

STAGE

TEMP

STAGE

(ODEP)

–Vcc

+Vcc

LVA

TRANSLATOR

AMP

ERROR

VARIABLE

GAIN STAGE

BALANCE

INPUT STAGE

LIMIT

CURRENT

BIAS

ODEP

P.I.P.

BARRIER

BALANCED

INPUT

BLOCK

–Vcc

LVA

TRANSLATOR

DISPLAY

ONLY ONE CHANNEL SHOWN

Fig. 5.1 Circuit Block Diagram

Page 27

Page 28

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

sitivity switch and the back panel level control. The error amp (U104-C) amplifies the difference between the output signal and the input signal from the gain pot, and drives the voltage translator stage.

From the error amp, the voltage translator stage channels the signal to the Last Voltage Amplifiers (LVAs), depending on the signal polarity. The +LVA (Q105) and the –LVA (Q110), with their push-pull effect through the bias servo Q318, drive the fully complementary output stage.

The bias servo Q318 is thermally coupled to the heat sink, and sets the quiescent bias current in the output stage to lower the distortion in the crossover region of the output signal. D301, D302, D303, and D304 are used to remove the charge on the unused portion of the output stage, depending on the polarity of the output signal.

With the voltage swing provided by the LVAs, the signal then gains current amplification through the Darlington emitter-follower output stage.

The bridge-balanced circuit (U104-D) receives a signal from the output of the amplifier, and differences it with the signal at the Vcc supply. The bridge-balanced circuit then develops a voltage to drive the bridge-balanced output stage. This results in the Vcc supply having exactly one half of the output voltage added to their quiescent voltage. D309, D310, D311 and a trimmer resistor set the quiescent current point for the bridgebalanced output stage.

The protection mechanisms that affect the signal path are implemented to protect the amplifier under real world conditions. These conditions are high instantaneous current, excessive temperature, and output device operation outside safe conditions.

Q107 and Q108 act as a conventional current limiter, sensing current in the output stage. When current at any one instant exceeds the design criteria, the limiters remove the drive from the LVAs, thus limiting current in the output stage to a safe level.

To further protect the output stages, the patented

ODEP

circuitry is used. It produces an analog output

proportional to the always changing

area

of the output transistor. This output controls the

safe operating

translator stage previously mentioned, removing any further drive that may exceed the

safe operating area

of the output stage.

Thermal sensors S100 and S200 give the

ODEP

circuits vital information on the operating temperature of the heat sink on which the output devices are mounted.

Should the amplifier fail in a way that would cause DC across the output lead, the DC protection circuit senses this on the negative feedback loop and shuts down the power supply until the DC is removed.

5.2.2 Bridge-Mono Operation

By setting the dual/mono switch on the back panel to Bridge-Mono, the user can convert the

Com-Tech

into a bridge-mono amplifier. With a signal applied to the channel 1 input jack, and the load between the positive (+) output terminals on the back panel, twice the voltage can be output.

The channel 1 output feeds the channel 2 error amp U204-A. Because there is a net inversion, the channel 2 output is out of polarity with channel 1. This produces twice as much voltage across the load. Each of the channel’s protection mechanisms work independently if a fault occurs.

5.2.3 Parallel-Mono Operation

With the dual/mono switch set to Parallel-Mono, the output of channel 2 is paralleled with the output of channel 1. A suitable high current-handling jumper must be connected across the positive (+) output terminals to gain the benefits of this operating mode.

The signal path for channel 1 is the same as previously discussed, except that channel 1 also drives the output stage of channel 2. The channel 2 balanced input, error amp, translators and LVAs are disconnected and no longer control the channel 2 output stage. Disconnecting the front-end stages from the output causes the channel 2 IOC circuit to note that the input waveform (which is absent) does not match the output waveform (which is driven by the channel 1 input). This is why the channel 2 IOC light is activated any time the amplifier is switched into Parallel-Mono mode. The channel 2 output stage and protection mechanisms are also coupled through S1 and function as one.

In Parallel-Mono mode, twice the current of a single

ODEP

channel is available. Because the channel 2

circuit is coupled through S1, you have added protection if a fault occurs in the channel 2 output stage. The channel 2

ODEP

circuit will limit the output of both output stages by removing the drive from the channel 1 translator stages.

Page 28

Page 29

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

Approved for THX Theatre

Systems

(CT-400 & 800)

120 VAC

North

American

Units:

6 Specifications

The following specifications apply to all models in Dual mode with 8 ohm loads and an input sensitivity of 26 dB unless otherwise specified. In Fire Protective Signaling Applications, the specifications in Section 9 supersede several of the specifications that follow.

Standard 1 kHz Power: This term refers to maximum average power in watts at 1 kHz with 0.1% THD.

Full Bandwidth Power: This term refers to maximum average power in watts from 20 Hz to 20 kHz with 0.1% THD.

120 VAC, 60 Hz Units: These North American units have dedicated transformers for 120 VAC, 60 Hz power mains.

100/120 VAC Units: These units have two-tap transformers that accept a 50 or 60 Hz AC line, and can be configured for 100 or 120 VAC mains.

220/240 VAC Units: These units have two-tap transformers that accept a 50 or 60 Hz AC line, and can be configured for 220 or 240 VAC mains.

Commercial Audio E106377

Fire Protective

Signaling S5206

Commercial

Audio LL 32521C

Slew Rate: Greater than 17 volts per microsecond. Voltage Gain: (At the maximum level setting) 20:1 ±3%

or 26 dB ±0.25 dB. 90:1 ±12% or 39 dB ±1 dB with the input sensitivity set to 0.775 volts for 70 volt output. The following voltage gain specifications are for units with the input sensitivity set to 0.775 volts for 8/4 ohm output:

Com-Tech 200 Com-Tech 400 Com-Tech 800 Com-Tech 1600

: 38:1 ±12% or 32 dB ±1 dB. : 55:1 ±12% or 35 dB ±1 dB. : 64:1 ±12% or 36 dB ±1 dB.

: 85:1 ±12% or 39 dB ±1 dB.

Power

Output Power:

for standard 1 kHz power from 120 VAC, 60 Hz North American units. For more information or specs on international units, see the power matrices that follow.

The following are guaranteed minimums

Performance

Frequency Response: ±0.1 dB from 20 Hz to 20 kHz at 1 watt (see Figure 6.9).

Phase Response: ±10 degrees from 10 Hz to 20 kHz at 1 watt (see Figure 6.12).

Hum and Noise: A-weighted, 105 dB below full bandwidth power; No weighting, 100 dB below full bandwidth power.

Total Harmonic Distortion (THD): Less than 0.05% at full bandwidth power from 20 Hz to 1 kHz increasing linearly to less than 0.1% at 20 kHz.

Intermodulation Distortion (IMD): (60 Hz and 7 kHz 4:1) Less than 0.05% from less than 166 milliwatts to full bandwidth power.

Damping Factor: Greater than 1000 from 10 Hz to 400 Hz (see Figure 6.10).

Crosstalk: See Figure 6.13. Common Mode Rejection Ratio (CMRR): Better than

70 dB.

Com-Tech 200

Dual mode (with both channels driven):

150 watts into 4 ohms. 110 watts into 8 ohms. 110 watts with 70 volt output.

Bridge-Mono mode:

300 watts into 8 ohms. 220 watts into 16 ohms. 205 watts in 70 volt mode (140 volt output).

Parallel-Mono mode:

295 watts into 2 ohms. 215 watts into 4 ohms. 210 watts with 70 volt output.

Com-Tech 400

Dual mode (with both channels driven):

240 watts into 4 ohms. 220 watts into 8 ohms. 225 watts with 70 volt output.

Bridge-Mono mode:

475 watts into 8 ohms. 450 watts into 16 ohms. 455 watts in 70 volt mode (140 volt output).

Page 29

Page 30

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

Parallel-Mono mode:

440 watts into 2 ohms. 440 watts into 4 ohms. 455 watts with 70 volt output.

Com-Tech 800

Dual mode (with both channels driven):

490 watts into 4 ohms. 305 watts into 8 ohms. 460 watts with 70 volt output.

Bridge-Mono mode:

975 watts into 8 ohms. 610 watts into 16 ohms. 920 watts in 70 volt mode (140 volt output).

Parallel-Mono mode:

965 watts into 2 ohms. 610 watts into 4 ohms. 915 watts with 70 volt output.

Com-Tech 1600

Dual mode (with both channels driven):

870 watts into 4 ohms. 540 watts into 8 ohms. 960 watts with 70 volt output.

Bridge-Mono mode:

1,745 watts into 8 ohms. 1,080 watts into 16 ohms. 1,805 watts in 70 volt mode (140 volt output).

Parallel-Mono mode:

1,745 watts into 2 ohms. 1,080 watts into 4 ohms. 1,780 watts with 70 volt output.

It is extremely important to supply the amplifier with adequate AC power. Power amplifiers cannot create energy—they need the required voltage and current to deliver the undistorted rated wattages you expect.

Load Impedance: Safe with all types of loads. With 8/4 ohm output, all Dual mode, 8 to 16 ohms in Bridge-Mono mode, and 2 to 4 ohms in Parallel-Mono mode. With 70 volt output, rated loads vary among the different models for each dual/mono mode (see the power matrices that follow).

Required AC Mains: All units draws 90 watts or less at idle. See Section 7 for detailed information on AC power draw, current draw and thermal dissipation.

Low-Voltage Power Supply: ±15 VDC regulated supplies are provided by a winding on the AC mains power transformer.

Power Cord: An appropriate AC line cord is provided with a minimum cable length of 5 feet (see Section 2).

Com-Techs

are rated for 4 to 8 ohms in

Controls

Enable: A front panel rocker switch used to turn the amplifier on and off.

Level: A detented 22-position back panel level control for each channel.

Output Mode: A back panel switch for each channel used to select 8/4 ohm or 70 volt output.

Dual/Mono: A three-position back panel switch used to select Dual, Bridge-Mono or Parallel-Mono operation.

Reset: A back panel push button used to reset the amplifier’s AC mains breaker.

Sensitivity: A three-position switch inside the partment used to select an input sensitivity for both channels: 0.775 volts for standard 1 kHz power in 8/4 ohm mode, 0.775 volts for standard 1 kHz power in 70 volt mode, or a voltage gain of 26 dB (see Section 4.4).

P.I.P.

com-

Indicators

Enable: This amber indicator shows the on/off status of the unit’s low-voltage power supply.

Signal Presence (SPI): Each channel has a green indi- cator that flashes to show audio output.

IOC

: Each channel has a yellow indicator that flashes if

the output waveform differs from the input waveform by

0.05% or more. The LEDs act as sensitive distortion indicators to provide Parallel-Mono mode, the channel 2 on.

ODEP

: Each channel has a green multifunction indi-

cator that shows the channel’s reserve energy status. Normally, the LEDs are brightly lit to show that reserve energy is available. In the rare event that a channel has no reserve, its indicator will dim in proportion to limiting. An other more unusual circumstances (see Section 4.2).

proof of distortion-free performance

IOC

indicator stays

ODEP

indicator may also turn off under

. In

ODEP

Input/Output

Input Connector: A barrier block on the standard

with three-terminal balanced connections for input

to each channel. Input Impedance: Nominally 20 K ohms, balanced.

Nominally 10 K ohms, unbalanced. Input Sensitivity: Settings include 0.775 volts for 8/4

ohm output, 0.775 volts for 70 volt output, and a voltage gain of 26 dB.

Output Connector: A back panel barrier block with two-

P.I.P.-

Page 30

Page 31

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

terminal connections for each output channel. Output Impedance: Less than 10 milliohms in series

with less than 2 microhenries (see Figure 6.11). DC Output Offset: Less than ±10 millivolts.

Output Signal

Dual: Unbalanced, two-channel. Bridge-Mono: Balanced, single-channel. Channel 1

controls are active; channel 2 should be turned down. Parallel-Mono: Unbalanced, single-channel. Chan-

nel 1 controls are active; channel 2 is bypassed.

Protection

Com-Tech

open or mismatched loads; overloaded power supplies; excessive temperature, chain destruction phenomena, input overload damage and high-frequency blow-ups. They also protect loudspeakers from input/ output DC and turn-on/turn-off transients.

If unreasonable operating conditions occur, the patented level to protect the output devices, particularly in the case of elevated temperature. Transformer overheating will result in a temporary shutdown of both channels; when it has cooled to a safe temperature, the transformer will automatically reset itself. Controlled slew rate voltage amplifiers protect against RF burnouts, and input overload protection is provided by current-limiting resistance at the input.

Turn On: The four second turn-on delay prevents dangerous turn-on transients. Turn-on occurs at zero crossing of the AC waveform, so power sequencers are rarely needed with multiple units.

delay time may be changed. Contact Crown’s Technical Support Group for details.

Circuit Breaker: Circuit breaker current ratings vary based on the

All 100/120 VAC Units:

All 220/240 VAC Units:

amplifiers are protected against shorted,

ODEP

circuitry will proportionally limit the drive

Note: The turn-on

Com-Tech

Com-Tech 200 Com-Tech 400 Com-Tech 800 Com-Tech 1600

Com-Tech 200 Com-Tech 400

model and AC mains voltage.

: 8 amperes. : 15 amperes. : 20 amperes.

: 30 amperes.

: 4 amperes. : 8 amperes.

Com-Tech 800 Com-Tech 1600

: 10 amperes.

: 20 amperes.

Construction

Durable black finish on the steel chassis, front panel Lexan overlay, and specially-designed flow-through ventilation from front to side panels.

Cooling: Internal heat sinks with on-demand forced air cooling (fan is optional for the North American

Tech 200

Dimensions: 19 inch (48.3 cm) standard rack mount width (EIA RS-310-B), 16 inch (40.6 cm) depth behind mounting surface, and 0.25 inches (0.6 cm) in front of mounting surface. Amplifier height varies among the available models and with different AC mains voltage requirements (see Section 3.1).

Approximate Weight: Center of gravity is 6 inches (15.2 cm) behind the front mounting surface.

120 VAC, 60 Hz North American Units:

100/120 VAC, 50/60 Hz Units:

220/240 VAC, 50/60 Hz Units:

; see Sections 3.2.1 and 8.2).

Com-Tech 200

33 pounds, 14 ounces (15.4 kg) shipping weight.

Com-Tech 400

36 pounds, 6 ounces (16.5 kg) shipping weight.

Com-Tech 800

50 pounds, 8 ounces (22.9 kg) shipping weight.

Com-Tech 1600

net; 66 pounds, 10 ounces (30.2 kg) shipping weight.

Com-Tech 200

35 pounds, 8 ounces (16.1 kg) shipping weight.

Com-Tech 400

43 pounds, 4 ounces (19.6 kg) shipping weight.

Com-Tech 800

49 pounds, 10 ounces (22.5 kg) shipping weight.

Com-Tech 1600

net; 64 pounds, 3 ounces (29.1 kg) shipping weight.

Com-Tech 200

35 pounds, 14 ounces (16.3 kg) shipping weight.

Com-Tech 400

42 pounds, 12 ounces (19.4 kg) shipping weight.

Com-Tech 800

49 pounds, 13 ounces (22.6 kg) shipping weight.

Com-Tech 1600

64 pounds, 10 ounces (29.3 kg) shipping weight.

: 29 pounds, 7 ounces (13.4 kg) net;

: 31 pounds, 15 ounces (14.5 kg) net;

: 47 pounds, 4 ounces (21.5 kg) net;

: 57 pounds, 14 ounces (26.3 kg)

: 31 pounds, 6 ounces (14.2 kg) net;

: 38 pounds, 15 ounces (17.7 kg) net;

: 45 pounds, 1 ounces (20.5 kg) net;

: 54 pounds, 11 ounces (24.8 kg)

: 31 pounds, 12 ounces (14.4 kg) net;

: 38 pounds, 7 ounces (17.5 kg) net;

: 45 pounds, 4 ounces (20.5 kg) net;

: 55 pounds, 2 ounces (25.0 kg) net;

Com-

Page 31

Page 32

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

Crown specifications are guaranteed for three years.

In an effort to provide you with as much information as possible about the high power-producing capabilities of your amplifier, we have created the following power matrices.

Minimum Guaranteed Power Specifications

Crown’s minimum power specifications represent the absolute smallest amount of output power you can expect from your amplifier when it is driven to full output under the given conditions. Some spaces in each matrix may be left blank because the same guarantee is not provided for those conditions—however, your amplifier will perform well under each matrix.

When measuring power, 0.1% THD appears to be the industry standard for distortion. Two of the maximum average power specifications shown in each minimum power matrix are measured at 0.1% THD so you can easily compare Crown specifications to those of other manufacturers. But this high level of distortion actually allows for some clipping which is undesirable. Because of this, a maximum average power specification at 0.05% THD is included in each minimum power matrix which represents non-clipped conditions. Although most manufacturers do not give you power specifications at 0.05% THD, we encourage them to provide these specifications so you will have a more realistic representation of the way amplifiers should be used in the real world—without a clipped output signal.

Many manufacturers publish power specs with a tolerance of ±1 dB or worse. This means their amplifier can deviate more than 20% in output! A 100 watt amplifier would meet their specification if it only produced 79.4 watts. Other manufacturers qualify

their specs by saying they are “typical,” “sub-

Com-Tech 200 – Minimum Guaranteed Power (Watts)

Dual/Mono

Mode

AC Mains120 VAC, 60 Hz

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

Parallel-Mono

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

100/120 VAC, 50/60 Hz

Parallel-Mono

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

220/240 VAC, 50/60 Hz

Parallel-Mono

1 00 ( 140V)

Load in Ohms

(Constant Voltage)

4 8

50 (70V)

2 4

25 (70V)

4 8

50 (70V)

2 4

25 (70V)

4 8

50 (70V)

2 4

25 (70V)

At 0.1% THD

(See note 1)

1 kHz

150 110 110 300 220 205 295 215 210 145 110 105 290 220 205 290 215 210 150 115 105 300 230 215 300 225 215

Maximum Average

At 0.1% THD (See note 2)

20Hz-20kHz

135 105 105 270 210 200

135 105

95 265 210 195

140 110 100 275 220 200

At 0.05% THD

(See note 3)

1 kHz

145 105 110 295 215 205 290 210 205 145 110 105 285 220 205 285 210 205 150 115 105 295 225 210 300 225 215

FTC Continuous Average

At 0.1% THD

(See note 4)

1 kHz 20Hz-20kHz

140 105 110 270 210 205 275 215 205 135 110 100 275 215 205 270 210 205 140 110 105 280 225 210 275 220 210

125 100 105 250 205 200

125 105

95 250 205 190

130 105

95 260 215 195

ject to manufacturing tolerances,” “single channel driven” or that they are specified with “fuses bypassed.” Each of these statements effectively removes any performance guarantee. In fact, some manufacturers use these tactics to generate large power numbers, and they don’t even print a disclaimer. We take a different approach at Crown—our amplifiers

guaranteed

are

to meet or exceed their specifications for three years. Further, because our published specs are set below our “in-house” measurements, you can expect amplifier to

exceed

power specs. We believe you should get what you pay for.

Minimum Power Notes:

All minimum power specifications are based on 0.5% regulated AC mains with THD of less than 1.0% and an ambient room temperature of 70° F (21° C). Standard EIA power (RS-490) is not shown here because it is identical to FTC Continuous Average Power.

1. A 1 kHz sine wave is presented to the amplifier

and the output monitored for nonlinear distortion. The level is increased until THD reaches 0.1%. At this point, average power per channel is reported.

2. A sine wave is presented to the amplifier over

the range from 20 Hz to 20 kHz and the output monitored for nonlinear distortion. The level at each frequency is increased until THD reaches

0.1%. At this point, average power per channel is reported.

3. A 1 kHz sine wave is presented to the amplifier

and the output monitored for nonlinear distortion. The level is increased until THD reaches 0.05%. At this point, average power per channel is reported.

4. Continuous power in the context of Federal T rade

Commission testing is understood to be a minimum of five minutes of operation. Harmonic distortion is measured as the RMS sum total and given as a percentage of the fundamental output voltage. This applies for all wattages greater than

Fig. 6.1 Com-Tech 200 Minimum Power Matrix

0.25 watts.

all conditions listed in

every

Crown

its published minimum

Page 32

Page 33

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

Com-Tech 400 –

Dual/Mono

Mode

AC Mains120 VAC, 60 Hz

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

Parallel-Mono

12.5 (70V)

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

100/120 VAC, 50/60 Hz

Parallel-Mono

12.5 (70V)

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

220/240 VAC, 50/60 Hz

Parallel-Mono

12.5 (70V)

Load in Ohms

(Constant Voltage)

4 8

25 (70V)

50 (140V)

2 4

4 8

25 (70V)

50 (140V)

2 4

4 8

25 (70V)

50 (140V)

2 4

Minimum Guaranteed Power (Watts)

Maximum Average

At 0.1% THD

(See note 1)

1 kHz

240 220 225 475 450 455 440 440 455 240 220 225 465 435 455 450 445 455 240 220 225 465 445 460 430 435 455

At 0.1% THD

(See note 2)

20Hz-20kHz

215 210 215 425 425 435

215 205 220 415 410 435

215 210 220 415 420 440

At 0.05% THD

(See note 3)

1 kHz

235 220 225 465 440 450 430 440 450 235 215 225 455 435 450 445 445 450 240 220 225 455 440 455 425 430 455

FTC Continuous Average

At 0.1% THD

(See note 4)

1 kHz 20Hz-20kHz

225 215 215 440 430 435 415 425 440 225 215 220 430 430 440 420 435 440 225 215 220 435 435 445 405 430 450

200 205 205 405 405 415

200 200 210 380 405 415

200 205 215 390 410 430

Fig. 6.2 Com-Tech 400 Minimum Power Matrix

Page 33

Page 34

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

Com-Tech 800 –

Dual/Mono

Mode

AC Mains120 VAC, 60 Hz

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

Parallel-Mono

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

100/120 VAC, 50/60 Hz

Parallel-Mono

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

220/240 VAC, 50/60 Hz

Parallel-Mono

12.5 (70V)

25 (140V)

6.25 (70V)

12.5 (70V)

25 (140V)

6.25 (70V)

12.5 (70V)

25 (140V)

6.25 (70V)

At 0.1% THD

(See note 1)

Load in Ohms

(Constant Voltage)

4 8

2 4

4 8

2 4

4 8

2 4

Minimum Guaranteed Power (Watts)

Maximum Average

1 kHz

490 305 460 975 610 920 965 610 915 460 300 425 925 600 855 925 600 855 485 310 440 965 620 885 940 615 875

At 0.1% THD

(See note 2)

20Hz-20kHz

460 295 455 935 600 905

440 290 415 885 580 825

470 305 430 920 605 855

At 0.05% THD

(See note 3)

1 kHz

480 300 455 965 605 905 950 600 905 460 295 420 915 595 850 920 595 845 485 310 435 955 615 875 930 610 870

FTC Continuous Average

At 0.1% THD

(See note 4)

1 kHz 20Hz-20kHz

470 300 450 950 605 905 950 605 910 445 295 410 890 595 830 895 595 830 465 310 425 930 615 865 920 600 855

455 290 445 905 600 880

425 290 400 840 575 800

450 300 420 875 600 840

Fig. 6.3 Com-Tech 800 Minimum Power Matrix

Page 34

Page 35

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

Com-Tech 1600 –

Dual/Mono

Mode

AC Mains120 VAC, 60 Hz

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

Parallel-Mono

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

100/120 VAC, 50/60 Hz

Parallel-Mono

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

220/240 VAC, 50/60 Hz

Parallel-Mono

6.25 (70V)

12.5 (1 40V)

3.13 (70V)

6.25 (70V)

12.5 (1 40V)

3.13 (70V)

6.25 (70V)

12.5 (1 40V)

3.13 (70V)

At 0.1% THD

(See note 1)

Load in Ohms

(Constant Voltage)

4 8

2 4

4 8

2 4

4 8

2 4

Minimum Guaranteed Power (Watts)

Maximum Average

1 kHz

870 540

960 1,745 1,080 1,805 1,745 1,080 1,780

815

535

860 1,625 1,070 1,700 1,660 1,080 1,700

840

545

875 1,675 1,090 1,755 1,650 1,075 1,745

At 0.1% THD

(See note 2)

20Hz-20kHz

810 520

910 1,595 1,040 1,725

775

515

830 1,545 1,035 1,640

785

525

755 1,550

910 1,315

At 0.05% THD

(See note 3)

1 kHz

860 535

955 1,725 1,070 1,795 1,720 1,070 1,760

805

530

850 1,615 1,060 1,695 1,640 1,070 1,690

840

540

870 1,665 1,075 1,745 1,635 1,065 1,735

FTC Continuous Average

At 0.1% THD

(See note 4)

1 kHz 20Hz-20kHz

850 540

960 1,700 1,075 1,770 1,690 1,075 1,745

530

815

1,055 1,625

1,060 1,620

540

850

1,070 1,710

1,065 1,715

510

1,040

510

1,020

505

900

Fig. 6.4 Com-Tech 1600 Minimum Power Matrix

Page 35

Page 36

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

Maximum Power Specifications

Crown’s maximum power specifications represent the largest amount of output power you can expect from your amplifier when it is driven to full output under the given conditions. These specifications can be used to prevent loudspeaker and hearing damage.

The maximum power matrices include specifications for single cycle and 40 millisecond burst sine waves. Burst signals act like large transient peaks that are present in common source signals. Loudspeakers can respond to a single cycle burst, so the single cycle burst specifications should be used to help you protect your loudspeakers. In contrast, a 40 millisecond burst represents the typical response time of the human ear. Your ear will not respond to the entire dynamic change of a burst that lasts less than 40 milliseconds.

The burst power specifications are provided at 0.05% THD which is a practical low distortion condition. Operating the amplifier at levels higher than 0.05% THD can result in output power levels that are higher than those listed in the maximum power matrices.

Dual/Mono

Mode

AC Mains120 VAC, 60 Hz 100/120 VAC, 50/60 Hz

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

1 00 ( 140V)

Parallel-Mono

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

1 00 ( 140V)

Parallel-Mono

Dual

(both channels

driven)

Bridge-Mono

(balanced output)

220/240 VAC, 50/60 Hz

1 00 ( 140V)

Parallel-Mono

Load in Ohms

(Constant Voltage)

4 8

50 (70V)

2 4

25 (70V)

4 8

50 (70V)

2 4

25 (70V)

4 8

50 (70V)

2 4

25 (70V)

Com-Tech 200 –

Single Cycle Tone Burst

20 Hz 50 Hz 1 kHz

170 130 130 355 255 255 345 255 255 165 125 140 325 250 275 325 245 275 165 130 140 330 250 305 315 250 280

Maximum Power (Watts)

At less than 0.05% THD

(See note 1)

205 145 135 400 280 270 405 280 270 220 155 150 435 300 295 425 305 295 225 155 150 440 310 310 425 305 295

275 165 140 535 325 275 520 315 280 310 185 150 600 360 305 580 355 305 315 185 155 625 370 315 595 365 305

7 kHz

275 165 135 530 320 265 520 315 265 305 180 145 605 360 290 585 355 290 310 185 150 625 370 300 590 360 295

40 Millisecond Tone Burst

At 0.05% THD

(See note 2)

50 Hz 1 kHz

175 130 130 345 250 255 345 245 255 190 135 140 380 265 275 360 265 275 190 140 140 375 270 310 370 270 280

155 115 125 310 225 250 300 220 245 165 125 135 325 245 265 310 235 265 165 125 135 325 245 310 315 240 270

7 kHz

165 120 130 325 240 255 315 230 255 175 130 140 345 255 275 335 250 275 175 130 140 345 260 300 335 255 280

Maximum Power Notes:

All maximum power specifications are based on 0.5% regulated AC mains with THD of less than 1.0% and an ambient room temperature of 70° F (21° C). Although it is an unusual condition, your amplifier can function well with AC mains voltages up to 10% over the specified line voltage. With overvoltage conditions, your amplifier may be capable of delivering instantaneous power levels up to 20% greater than the specifications in the matrix.

1. 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 .

2. A 40 millisecond sine wave burst (10 percent duty cycle) is presented to the amplifier and monitored for nonlinear distortion. Average power during the burst is reported. This power level is a measurement of the amplifier’s maximum transient power that can be perceived by the human ear.

Fig. 6.5 Com-Tech 200 Maximum Power Matrix

Page 36

Page 37

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

Dual/Mono

Mode

AC Mains120 VAC, 60 Hz 100/120 VAC, 50/60 Hz

Dual

(both channels

driven)

25 (70V)

Bridge-Mono

(balanced output)

50 (140V)

Parallel-Mono

12.5 (70V)

Dual

(both channels

driven)

25 (70V)

Bridge-Mono

(balanced output)

50 (140V)

Parallel-Mono

12.5 (70V)

Dual

(both channels

driven)

25 (70V)

Bridge-Mono

(balanced output)

50 (140V)

220/240 VAC, 50/60 Hz

Parallel-Mono

12.5 (70V)

Load in Ohms

(Constant Voltage)

4 8

2 4

4 8

2 4

4 8

2 4

Com-Tech 400 –

Single Cycle Tone Burst

At less than 0.05% THD

20 Hz 50 Hz 1 kHz

320 265 305 620 520 590 615 505 595 315 240 280 620 475 555 610 470 550 315 240 280 625 475 665 605 465 550

Maximum Power (Watts)

(See note 1)

415 300 330 820 600 655 805 595 650 415 285 310 820 570 615 790 560 615 405 285 315 820 575 675 745 565 610

460 360 340 875 720 675 825 715 680 555 330 325

1,110

665 645

1,080

655 645 435 335 325 860 665 680 745 645 645

7 kHz

450 355 330 855 705 655 810 700 655 550 325 315

1,095

660 630

1,070

640 620 435 325 315 865 655 650 745 640 620

40 Millisecond Tone Burst

At 0.05% THD

(See note 2)

50 Hz 1 kHz

345 260 305 695 510 600 685 515 600 360 255 285 725 500 565 710 495 565 360 250 290 725 500 675 700 490 565

315 235 290 620 475 575 615 470 575 315 230 270 620 455 540 605 450 535 310 230 275 625 455 675 600 445 535

7 kHz

330 250 305 645 490 595 645 490 695 330 240 280 655 480 565 635 470 560 330 240 285 650 480 650 625 465 555

Fig. 6.6 Com-Tech 400 Maximum Power Matrix

Page 37

Page 38

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

Dual/Mono

Mode

AC Mains120 VAC, 60 Hz 100/120 VAC, 50/60 Hz

Dual

(both channels

driven)

12.5 (70V)

Bridge-Mono

(balanced output)

25 (140V)

Parallel-Mono

6.25 (70V)

Dual

(both channels

driven)

12.5 (70V)

Bridge-Mono

(balanced output)

25 (140V)

Parallel-Mono

6.25 (70V)

Dual

(both channels

driven)

12.5 (70V)

Bridge-Mono

(balanced output)

25 (140V)

220/240 VAC, 50/60 Hz

Parallel-Mono

6.25 (70V)

Load in Ohms

(Constant Voltage)

4 8

2 4

4 8

2 4

4 8

2 4

Com-Tech 800 –

Single Cycle Tone Burst

At less than 0.05% THD

20 Hz 50 Hz 1 kHz

515 320 480

1,010

640 980

1,060

645 975 460 230 475 915 600 920 900 600 915 475 305 475 930 605 920 910 600 915

575 340 530

1,120

680 1,045 1,160

685 1,045

605

295

545 1,195

705 1,085 1,195

700 1,070

610

360

545 1,190

705 1,085 1,185

710 1,080

Maximum Power (Watts)

(See note 1)

695 385 590

1,405

770 1,185 1,390

765 1,170

750

375

610 1,500

810 1,230 1,485

805 1,210

755

405

615 1,530

815 1,225 1,475

790 1,225

7 kHz

690 375 575

1,385

755 1,145 1,380

755 1,135

730

370

595 1,480

790 1,190 1,450

780 1,185

740

395

590 1,470

785 1,180 1,415

770 1,175

40 Millisecond Tone Burst

At 0.05% THD

(See note 2)

50 Hz 1 kHz

545 320 480

1,060

650 960

1,100

650 985 555 275 510

1,110

665 990

1,075

660 975 570 340 505

1,095

675 980

1,085

665 985

470 300 455 945 595 910 950 590 910 470 235 470 935 600 910 920 600 905 485 305 475 945 605 910 920 595 910

7 kHz

495 310 475 995 620 955 985 615 945 490 245 490 980 630 955 960 625 945 500 320 490 985 635 945 955 620 940

Fig. 6.7 Com-Tech 800 Maximum Power Matrix

Page 38

Page 39

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

Dual/Mono

Mode

AC Mains120 VAC, 60 Hz 100/120 VAC, 50/60 Hz

Dual

(both channels

driven)

6.25 (70V)

Bridge-Mono

(balanced output)

12.5 (1 40V)

Parallel-Mono

3.13 (70V)

Dual

(both channels

driven)

6.25 (70V)

Bridge-Mono

(balanced output)

12.5 (1 40V)

Parallel-Mono

3.13 (70V)

Dual

(both channels

driven)

6.25 (70V)

Bridge-Mono

(balanced output)

12.5 (1 40V)

220/240 VAC, 50/60 Hz

Parallel-Mono

3.13 (70V)

Com-Tech 1600 –

Load in Ohms

(Constant Voltage)

4 8

2 4

4 8

2 4

4 8

2 4

Maximum Power (Watts)

Single Cycle Tone Burst

At less than 0.05% THD

(See note 1)

20 Hz 50 Hz 1 kHz

780 525

950 1,600 1,050 1,770 1,590 1,140 1,895

820

555

955 1,635 1,090 1,895 1,640 1,090 1,845

800

535

885 1,600 1,055 1,800 1,615 1,065 1,855

1,000

600 1,035 1,995 1,185 1,980 1,985 1,170 2,015 1,060

655 1,100 2,095 1,285 2,165 2,105 1,300 2,110 1,060

630 1,025 2,060 1,225 2,115 2,100 1,230 2,080

1,245

670 1,205 2,480 1,330 2,315 2,465 1,330 2,375 1,370

750 1,295 2,700 1,475 2,550 2,715 1,470 2,530 1,295

700 1,210 2,580 1,410 2,475 2,585 1,415 2,450

7 kHz

1,215

655 1,170 2,420 1,285 2,225 2,390 1,300 2,280 1,335

720 1,255 2,680 1,440 2,490 2,630 1,425 2,430 1,245

685 1,165 2,520 1,365 2,395 2,525 1,380 2,315

40 Millisecond Tone Burst

At 0.05% THD

(See note 2)

50 Hz 1 kHz

915 555

925 1,875 1,145 1,785 1,830 1,130 1,880 1,005

610 1,025 1,930 1,200 1,985 1,955 1,195 1,965

955

590

960 1,915 1,155 1,935 1,920 1,175 1,940

840 525

875 1,670 1,050 1,675 1,665 1,045 1,715

835

550

895 1,650 1,080 1,760 1,655 1,080 1,745

820

530

845 1,630 1,050 1,720 1,635 1,055 1,720

7 kHz

870 545

905 1,745 1,090 1,735 1,715 1,080 1,780

870

570

930 1,735 1,130 1,825 1,725 1,120 1,810

850

550

875 1,695 1,095 1,800 1,700 1,095 1,785

Fig. 6.8 Com-Tech 1600 Maximum Power Matrix

Page 39

Page 40

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

–1

–2

–3

–4

–5

–6

–7

10 100 1 K 10 K 100 K

FREQUENCY (Hz)

1 watt

8 ohm 4 ohm

Fig. 6.9 Typical Frequency Response

1400

1200

MILLIOHMS

504.0

126.8

31.8

1000

800

600

400

200

100

100 1 K 10 K

FREQUENCY (Hz)

8 ohm

20 K

Fig. 6.10 Typical Damping Factor

6 dB

8.0

2.0

Page 40

10 100 1 K 10 K 100 K

FREQUENCY (Hz)

Fig. 6.11 Typical Output Impedance

Page 41

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

(Hz)

+45˚

0˚

–45˚

TEF

Measurement

TECHRON TEF

100 1 K 10 K 20 K

FREQUENCY

Fig. 6.12 Typical Phase Response

TEF

Measurement

–66

–72

–78

–84

–90

–96

–102

TECHRON TEF

100 1 K 10 K 20 K

FREQUENCY

Fig. 6.13 Typical Crosstalk

Page 41

Page 42

7 AC Power Draw and

Current Draw

(amperes)

AC Mains Power

Draw (watts)

AC Mains

Voltage

Power

Factor (.83)

Thermal Dissipation

This section provides detailed information about the amount of power and current drawn from the AC mains by produced under various conditions. The calculations presented here are intended to pr ovide a realistic and reliable depiction of the amplifiers. The following assumptions or approximations were made:

Com-Tech

amplifiers and the amount of heat

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

• Duty cycle of continuous speech is 10%.

• Duty cycle of infrequent paging is 1%.

Here are the equations used to calculate the data presented in Figures 7.1 through 7.4:

AC Mains Power

Draw (watts)

Total output power with all

channels driven (watts)

Amplifier Efficiency (.65)

Duty

Cycle

Quiescent Power

Draw (watts)

• The amplifier’s available channels are loaded, and full power is being delivered.

• Amplifier efficiency at standard 1 kHz power is estimated to be 65%.

• In 8/4 ohm mode, typical quiescent power draw is 20 watts for the

400

, 55 watts for the

the

Com-Tech 1600

Com-T ech 200

Com-Tech 800

, 30 watts for the

and 70 watts for

Com-Tech

• In 70 volt mode, typical quiescent power draw is 30 watts for the

Com-Tech 400

and

1600

Com-Tech 200

, 35 watts for the

, and 90 watts for the

Com-Tech 800

• When running at full speed, typical power draw for the internal fan is 11 watts for the

800

, and 17 watts for the

an option for the

Com-Tech 200

Com-Tech 200, 400

Com-Tech 1600

and

(the fan is

• Quiescent thermal dissipation is related .

• The estimated duty cycles take into account the typical crest factor for each type of source material.

• Duty cycle of pink noise is 50%.

• Duty cycle of highly compressed rock ‘n’ roll midrange is 40%.

• Duty cycle of rock ‘n’ roll is 30%.

• Duty cycle of background music is 20%.

The value used for quiescent power draw includes both the amplifier’s quiescent power draw for the selected output mode and the power drawn by the fan if one is installed (these values are listed in the previous column). The following equation converts power draw in watts to current draw in amperes:

The power factor of 0.83 is needed to compensate for the difference in phase between the AC mains voltage and current. The following equation is used to calculate thermal dissipation:

Thermal

Dissipation

(btu/hr)

Total output power with all

channels driven (watts)

()

Amplifier Efficiency (.65)

Duty

Cycle

.35

Quiescent Power

Draw (watts)

3.415

The constant 0.35 is inefficiency (1.00– 0.65) and the factor 3.415 converts watts to btu/hr. Thermal dissipation in btu is divided by the constant 3.968 to get kcal. If you plan to measure output power under real-world conditions, the following equation may also be helpful:

Thermal

Dissipation

(btu/hr)

Total measured output power

from all channels (watts)

()

Amplifier Efficiency (.65)

.35

Quiescent Power

Draw (watts)

3.415

8 Ohm Dual / 16 Ohm Bridge-Mono / 4 Ohm Parallel-Mono

Duty

Cycle

50% 40% 30% 20% 10%

AC Mains

Power

Draw

(Watts)

200 165 135 100

Current Draw (Amps)

100-120 V 220-240 V

2.4

2.0

1.6

1.2

0.8

1.1

0.9

0.7

0.5

0.3

Thermal Dissipation

btu/hr

305 265 225 185 145

Fig. 7.1 Com-Tech 200 Power Draw, Current Draw and Thermal Dissipation at Various Duty Cycles

Page 42

Com-Tech 200

L O A D

4 Ohm Dual / 8 Ohm Bridge-Mono / 2 Ohm Parallel-Mono 70 V

kcal/hr

80 70 60 50 40

AC Mains

Power

Draw

(Watts)

265 215 170 125

Current Draw (Amps)

1.4

3.1

1.2

2.6

0.9

2.0

0.7

1.5

0.4

0.9

Thermal Dissipation

btu/hr

380 325 270 215 160

AC Mains

Power

kcal/hr100-120 V 220-240 V

Draw

(Watts)

210

175

145

110

Current Draw (Amps)

1.1

2.5

1.0

2.1

0.8

1.7

0.6

1.3

0.4

0.9

Thermal Dissipation

btu/hr

kcal/hr100-120 V 220-240 V

340

300

260

220

180

Page 43

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

8 Ohm Dual / 16 Ohm Bridge-Mono / 4 Ohm Parallel-Mono

Duty Cycle

50% 40% 30% 20% 10%

AC Mains

Power

Draw

(Watts)

390 320 250 180 110

Current Draw (Amps)

100-120 V 220-240 V

4.7

3.8

3.0

2.2

1.3

2.1

1.7

1.4

1.0

0.6

Thermal Dissipation

kcal/hr

btu/hr

140

550

120

470

100

385

305

220

Fig. 7.2 Com-Tech 400 Power Draw, Current Draw and Thermal Dissipation at Various Duty Cycles

8 Ohm Dual / 16 Ohm Bridge-Mono / 4 Ohm Parallel-Mono

Duty Cycle

50% 40% 30% 20% 10%

AC Mains

Power

Draw

(Watts)

535 440 350 255 160

Current Draw (Amps)

100-120 V 220-240 V

6.4

5.3

4.2

3.0

1.9

2.9

2.4

1.9

1.4

0.9

Thermal Dissipation

kcal/hr

btu/hr

200

785

170

670

140

560

115

450

335

Com-Tech 400

L O A D

4 Ohm Dual / 8 Ohm Bridge-Mono / 2 Ohm Parallel-Mono 70 V

AC Mains

Power

Draw

(Watts)

410 335 265 190 115

Current Draw (Amps)

2.2

4.9

1.8

4.0

1.4

3.2

1.0

2.3

0.6

1.4

Thermal Dissipation

btu/hr

580 490 400 315 225

AC Mains

kcal/hr100-120 V 220-240 V

150 125 100

80 60

Power

Draw

(Watts)

395 325 255 185 115

Current Draw (Amps)

4.8

3.9

3.1

2.2

1.4

Com-Tech 800

L O A D

4 Ohm Dual / 8 Ohm Bridge-Mono / 2 Ohm Parallel-Mono 70 V

AC Mains

Power

Draw

(Watts)

820 670 520 370 220

Current Draw (Amps)

4.5

9.9

3.7

8.0

2.8

6.2

2.0

4.4

1.2

2.6

Thermal Dissipation

btu/hr

1125

945 765 585 405

AC Mains

kcal/hr100-120 V 220-240 V

285 240 195 150 100

Power

Draw

(Watts)

810 670 525 385 245

Current Draw (Amps)

4.4

9.7

3.6

8.0

2.9

6.3

2.1

4.6

1.3

2.9

2.2

1.8

1.4

1.0

0.6

Thermal Dissipation

btu/hr

kcal/hr100-120 V 220-240 V

145

575

125

490

105

405

320

240

Thermal Dissipation

btu/hr

kcal/hr100-120 V 220-240 V

300

1190

260

1020

215

850

170

680

130

510

Fig. 7.3 Com-Tech 800 Power Draw, Current Draw and Thermal Dissipation at Various Duty Cycles

Com-Tech 1600

L O A D

8 Ohm Dual / 16 Ohm Bridge-Mono / 4 Ohm Parallel-Mono

Duty Cycle

50% 40% 30% 20% 10%

AC Mains

Power

Draw

(Watts)

920 755 590 425 260

Current Draw (Amps)

100-120 V 220-240 V

9.1

7.1

5.1

3.1

5.0

4.1

3.2

2.3

1.4

11.1

Thermal Dissipation

btu/hr

1300 1100

905 705 510

4 Ohm Dual / 8 Ohm Bridge-Mono / 2 Ohm Parallel-Mono 70 V

kcal/hr

330 280 230 180 130

AC Mains

Power

Draw

(Watts)

1435 1165

895 630 360

Current Draw (Amps)

7.6

4.3

7.8

6.4

4.9

3.4

2.0

17.3

14.0

10.8

Thermal Dissipation

btu/hr

1915 1590 1270

950 630

AC Mains

Power

485 400 320 240 160

Draw

(Watts)

1590 1295 1000

700 405

kcal/hr100-120 V 220-240 V

Current Draw (Amps)

19.1

15.6

12.0

8.4

4.9

Fig. 7.4 Com-Tech 1600 Power Draw, Current Draw and Thermal Dissipation at Various Duty Cycles

8.7

7.1

5.5

3.8

2.2

Thermal Dissipation

btu/hr

kcal/hr100-120 V 220-240 V

540

2140

450

1790

365

1435

275

1085

185

730

Page 43

Page 44

Note: In Fire Protective Signaling Systems, the Com-Tech 200 may

use the P.I.P.-BB, P.I.P.-ISO or P.I.P.-UL1711, however the Com-Tech 400, 800 and 1600 may

8 Accessories

8.1

P.I.P.

One advantage of customize them using cessor) modules. with an edge card connector inside the back panel compartment. The modules install easily:

Modules

Com-Tech

amplifiers is the ability to

P.I.P.

(Programmable Input Pro-

amplifiers are equipped

BACK PANEL

OF AMPLIFIER

.I.P

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

only use the P.I.P.-UL1711.

FTE

P.I.P.

Programmable Input Processor (P.I.P.)

P.I.P.-FTE includes all P.I.P.-FXT features, and adds 12 dB/octave RFI filters, variable 18 dB/octave highpass filters, and 6 dB/octave 3 kHz shelving networks for “constant-directivity” horn equalization. Screw terminal plugs are provided for input.

CH-2 INPUT CH-1 INPUT

+ – + –

Fig. 8.1 Installing a P.I.P. Module

WARNING: Disconnect power to the amplifier when installing or removing a

Here are some of the available

P.I.P.

module.

P.I.P.

modules:

AMC

Programmable Input Processor (P.I.P.)

OUTPUT INPUT

GND

P.I.P.-AMCb unites many features of the P.I.P.-XOV and P.I.P.-CLP. It offers a variable 4th-order Linkwitz-Riley crossover and an

IOC

-driven, variable threshold compressor. In addition, it provides “constant-directivity” horn equalization and filter-assisted B6 vented box equalization. Biamping and triamping capabilities are provided via XLR connectors.

EDC

CH-2 CH-1

P. I.P.

Programmable Input Processor

DATA OUT

AUX DSPI

CROWN

BUS

DATA IN

CH-2 CH-1

PUSHPUSH

AUDIO IN AUDIO IN

GND

IQ-P.I.P. v1.3 integrates the amplifier into Crown’s patented

IQ System

The

IQ System

provides centralized computer control of 1 to 2,000 amplifiers. Each amplifier channel can be monitored and controlled from an inexpensive personal computer. Any combination of mic- and line-level signals can also be mixed and routed with optional

MPX-6

,™

SMX-6

™

and

AMB-5

™

mixer/mul-

tiplexers, and the MRX series matrixers.

IQ-P.I.P. v1.4

Smart Amp

™

offers the monitoring and control features of the IQ-P.I.P. v1.3 plus the capability to function as a stand-alone unit as part of the

System’s distributed intelligence

.™ Features include a

smooth output limiter for transparent loudspeaker protection, power supply gates for energy savings,

ODEP

conservation which protects the output devices with precision input signal control, interrupt-driven reporting that lets you define error conditions, and configurable short detection.

PUSH

INPUT

Programmable Input Processor (P.I.P.)

PUSH

INPUT

P.I.P.-EDCb combines a sophisticated error -driven compressor and smooth limiter with a subsonic filter for each channel. The compressors have adjustable attack and release times, and can be set to track each other. The compressors activate when a signal will clip the input, an

IOC

error occurs, or the output exceeds the selected threshold. The subsonic filters have corner frequencies of 24, 28, 32 and 36 Hz.

Page 44

CLP

GND

Programmable Input Processor (P.I.P.)

CH-2 CH-1

PUSHPUSH

INPUT INPUT

GND

P.I.P.-CLP is designed to detect and prevent overload. Its compressor is driven by the amplifier’s built-in

IOC

error detection circuitry. Unlike typical signal-driven compressors, it only compresses the signal to prevent overload. It can deliver up to 13 dB of additional headroom without being noticeable.

Page 45

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

Programmable Input Processor (P.I.P.)

+– +–

LINE MIC

MIC

LEVEL

CH-2 INPUTS

CH-2 CH-1

REMOTE

+– +–

MIC LINE

MIC

LEVEL

CH-1 INPUTS

102

Programmable Input Processor (P.I.P.)

+– +–

OUT IN

CH-2

+– +–

IN OUT

CH-1

FIRE SAFETY

SYSTEMS

AUDIO SIGNAL

INPUTS

SYSTEM MONITOR

OUTPUTS

– + – +

CH-2 CH-1

CH-2 CH-1CH-2 CH-1

AMPLIFIER

ENABLE

Programmable Input Processor (P.I.P.)

1711

RPA

Programmable Input Processor

+–+

–

MIC

LINE

PHAN

TIE

RMT B

RMT A

OUT

RMT C

RMT D

+10 V

AUDIO BUS

CH-2 CH-1

MIC

LINE

PHAN

INPUT D

(CH-2)

INPUT C

(CH-2)

+–+

–

MIC

LINE

PHAN

MIC

LINE

PHAN

INPUT A

(CH-1)

INPUT B

(CH-1)

LEVEL

ISO

Programmable Input Processor (P.I.P.)

CH-2 INPUT

+ –

—WARNING—

THIS P.I.P. PROVIDES FULL ISOLATION

FOR ISO-MODIFIED AMPLIFIERS ONLY!

DO NOT CONNECT THE OUTPUT GROUND

LUG TO THE INPUT COMMON OR CHASSIS

GROUND. REFER TO P.I.P.–ISO OWNER’S

MANUAL FOR FURTHER INFORMATION.

CH-1 INPUT

+ –

P.I.P.-ISO is designed especially for 25 to 140 volt distributed systems where UL®-listed isolation is required. Installation requires minor amplifier modifications. With the P.I.P.-ISO installed, the amplifier outputs are safely isolated from the input terminals and the chassis.

ATN

Programmable Input Processor (P.I.P.)

CH-2 INPUT CH-1 INPUT

+ – + –

ATTENUATION ATTENUATION

30 36 44

P.I.P.-ATN includes all P .I.P.-FTE features, plus a 32-step precision attenuator for each channel.

XOV

TIP

RING

–

SLEEVE

GND

P.I.P.-P A adds a switchable balanced low-impedance mic input, a balanced line-level input and a compressor to each channel. Remote switching circuitry provides quick and quiet fades from mic to line and back.

P.I.P.-102 is a two-channel module providing equalization based on the BOSE® 102 controller . Screw terminal plugs provide balanced connections. Each input channel has an output from the

P.I.P.

that can be independently configured for output with no processing, 102 equalization or 102 equalization with bass-cut.

Programmable Input Processor (P.I.P.)

OUTPUTS INPUTS

P.I.P.-XOV is a versatile 18 dB/octave mono crossover/ filter with biamping and triamping capabilities.

FMX

PUSHPUSH

Programmable Input Processor (P.I.P.)

CH-2 INPUTS CH-1 INPUTS

P.I.P.-FMX facilitates “daisy-chaining” balanced amplifier inputs. Female to male three-pin XLR connectors are used to passively bridge the inputs.

FXT

Programmable Input Processor (P.I.P.)

CH-2 CH-1

PUSHPUSH

INPUT INPUT

P.I.P.-FXT uses balanced 1:1 transformers to isolate the amplifier from the input signal. It has balanced female three-pin XLR connectors.

PUSH

GND

P.I.P.-UL171 1 provides full compliance for

Com-Techs

in UL-listed fire protective signaling applications (see Section 9). Includes monitoring and remote on/off.

GND

P.I.P.-RPA adds the features of a 4x2 mixer to your amplifier. Its four inputs accept mic- or line-level input. It offers priority switching (“voice-over”) of each input and remote level control with the RPA-RMT. Other features

GND

include bus inputs and outputs, adjustable input sensitivity , phantom power and RFI suppression. Input isolation transformers are optional.

For more information on these or other

P.I.P.s

under development, contact your local dealer or Crown’ s T echnical Support Group.

Page 45

Page 46

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

8.2 Com-Tech 200 Cooling Fan

A three-speed cooling fan (part GCT200FAN) is available for North American units include a fan). We strongly recommend the kit if you will be operating a in high temperatures for long periods (see Section

3.2.1).

CAUTION: Because the installation of this fan involves the risk of electric shock, it should ONLY be attempted by a qualified technician.

Each cooling fan kit contains the following parts:

Fan motor (H42934-2)

Fan blade (C 9939-7)

Mounting bracket (F11106-6 or D 8439-8)

2 phillips flat head 6-32 machine screws (C 7062-0)

2 torx head 6-32 machine screws (A10110-70605)

Installation is not difficult, but you should be sure the unit’s power cord is unplugged before beginning.

1. Turn off the amplifier and disconnect its power cord from the AC power receptacle.

2. Remove the top cover of the amplifier. Use a phillips screwdriver to remove the two screws that secure it to the back panel. Gently pry the back of the cover up and away from the chassis, then pull the front up and back to unhook it.

WARNING: The power supply capacitors are very large and can cause shock. Always discharge them before working in close proximity.

3. Locate the two large power supply capacitors on

Com-Tech 200s

Com-Tech 200

FRONT

(all other

at high levels or

C 7062-0

F11106-6 or D 8439-8

A10110-70605

SUB–CHASSIS

C 9939-7

COLLAR

Fig. 8.3 Cooling Fan Assembly

either side of the

H42934-2

P.I.P.

compartment. Safely discharge them by placing a 100 ohm, 10 watt resistor across the + and – terminals of each capacitor. Use caution: DO NOT TOUCH the discharge resistor—it can become quite hot. (Use pliers to hold the resistor while you discharge the capacitors.)

4. Attach the fan motor to its bracket using the two flat head screws supplied in the kit (Figure 8.3). A phillips screwdriver is required.

5. Push the fan blade on the motor shaft until the shaft end is flush with the collar (Figure 8.3). The fan blades should be positioned so the collar faces away from the fan motor.

6. Attach the fan assembly to the subchassis (Figures 8.2 and 8.3) with the two torx head screws supplied in the kit (a torx nut driver is required). The fan motor assembly should be positioned with the wires facing the front of the amplifier.

TOP VIEW

Fig. 8.2 Cooling Fan Option

Page 46

7. Connect a wire from the fan motor to jumper block W3 and the remaining wire to W2 as shown in Figure 8.2. (It doesn’t matter which wire goes to which location because the fan uses an AC motor.)

8. Replace the cover and reconnect power.

8.3 Constant Voltage Computer

Crown’s constant voltage computer is a easy-to-use slide rule for audio applications. The first scale finds the impedance of a step-down transformer based on delivered power and the transformer’s rated voltage. This scale also identifies the proper transformer tap to use when a particular constant voltage rating is not provided with the transformer (such as 25, 35, 50, 70, 100 or 140 volts). Other scales include line loss, parallel resistance, dB-SPL vs. distance and dB-SPL vs. power. To get your own constant voltage computer, call Crown’s Technical Support Group and ask for literature.

Page 47

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

9 Fire Protective Signaling

Some installations are required to have an emergency public address system. For these systems, UL provides a special listing called Amplifiers for Fire Protective Signaling Systems. All UL-listed for this type of system.

Due to the strenuous nature of the classification, several requirements must be considered for proper installation:

1. The amplifier must be installed in a 19 inch rack mount enclosure that is UL-listed for use in Fire Pr otective Signaling Systems.

2. The amplifier must be installed in the same room as the Fire Alarm Control Unit.

3. The amplifier must be installed in accordance with the

National Electric Code

Fire Alarm Code

having jurisdiction.

4. The

Com-Tech 200

P.I.P.-UL1711

tion 8.1). All other

P.I.P.-UL1711

UL-listed Fire Alarm Control Unit.

5. The amplifier must be configured for 70 volt Dual mode operation.

6. The power requirement of the connected loudspeakers should not exceed the amplifier’s power rating for Fire Protective Signaling Systems (refer to the specification that follows).

When using a naling Application, UL does not require the installation of a

P.I.P.-UL1711

amplifiers. Even so, the desirable addition with its amplifier monitoring and remote on/off capabilities. With a

P.I.P.-UL1711

(NFPA 72) and the local authority

or a

Com-Tech

installed for supervision by a

Com-Tech 200

as they do for the other

is not installed, either the included

Com-Tech

(NFPA 70), the

must have a

P.I.P.-ISO

amplifiers must have a

in a Fire Protective Sig-

P.I.P.-UL1711

amplifiers are

installed (see Sec-

might still be a

Com-Tech 200

National

P.I.P.-BB

Com-Tech

, if a

, a

P.I.P.-BB

which vised by the Fire Alarm Control Unit. Please refer to Section 3.3.2 for

P.I.P.-UL1711

the wiring instructions provided in each For Fire Protective Signaling Applications, UL requires

an amplifier’ s output power ratings to be valid for emer gency operating conditions. This is why amplifiers have special 70 volt Dual mode power specifications for Fire Protective Signaling Applications. The channel, the channel, the channel, and the per channel. All models have a power bandwidth for this specification of 800 to 2,800 Hz. Crown guarantees these specification in accordance with the elevated operating temperature and strenuous conditions associated with emergency operation.

Current draw from the AC mains is also rated specifically for Fire Protective Signaling Applications. The

Com-Tech 200 400

rating of 9.0 amps, and the ing of 18.0 amps.

UL installation guidelines do not allow an amplifier to exceed its power rating for Fire Protective Signaling Applications. more power than this special rating suggests, so you must ensure that the total of the wattage ratings for the connected loudspeakers does not exceed the amplifier’ s requir ed power rating for UL listing.

The specifications provided in this section supersede those given in Section 6 only for Fire Protective Signaling Applications. For more information on using

Tech

tions, please refer to the or contact Crown’s Technical Support Group.

or a

P.I.P.-ISO

P.I.P.

is installed, the input wiring must be super-

and

must be installed. No matter

P.I.P.-BB

P.I.P.-ISO

wiring instructions. For

installation, please refer to

P.I.P.

manual.

Com-Tech

Com-Tech 200

Com-Tech 400 Com-Tech 800

Com-T ech 1600

has a rating of 3.0 amps, the

has a rating of 6.0 amps, the

Com-Tech

is rated for 50 watts per

is rated for 122 watts per is rated for 222 watts per

is rated for 350 watts

Com-Tech

Com-Tech 800

Com-Tech 1600

amplifiers can deliver much

has a

has a rat-

Com-

amplifiers in Fire Protective Signaling Applica-

P.I.P.-UL1711 Owner’s Manual

Page 47

Page 48

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

10 Service

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.

10.1 Worldwide Service

Service may be obtained from an authorized service center. (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. We will pay the surface shipping costs both ways for warranty service to the authorized service center nearest you after receiving copies of all shipping receipts. You must bear the expense of all taxes, duties, and customs fees when transporting the unit.

10.2 North American 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.

10.2.1 Service at a North American Service Center

This method usually saves the most time and effort. Simply 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. Remember to transport the unit in the original factory pack. A list of authorized service centers in your area can be obtained from our Technical Support Group.

10.2.2 Factory Service

To obtain factory service, fill out the service information page that follows and send it along with your proof of

purchase and the defective unit to the Crown factory. For warranty service, we will pay for ground shipping both ways in the United States after receiving copies of the shipping receipts. Shipments should be sent “UPS ground.” (If the unit is under warranty, you may send it C.O.D. for the cost of freight via UPS ground.) The factory will return it via UPS ground. Please contact us if other arrangements are required.

Always use the original factory pack to transport the unit.

Factory Service Shipping Instructions:

1. When sending a Crown product to the factory for service, be sure to fill out the service information form that follows and enclose it inside your unit’s shipping pack. Do not send the service information form separately.

2. To ensure the safe transportation of your unit to the factory, ship it in an original factory packing container. If you don’t have one, call or write Crown’s Parts Department. With the exception of polyurethane or wooden crates, any other packing material will not be sufficient to withstand the stress of shipping. Do not use loose, small size packing materi-

als.

3. Do not ship the unit in any kind of cabinet (wood or metal). Ignoring this warning may result in extensive damage to the unit and the cabinet. Accessories are not needed—do not send the instruction manual, cables and other hardware.

If you have any questions, please call or write the Crown Technical Support Group.

Page 48

Crown Audio Division

Tech. Support/Factory Service

57620 C.R. 105

Elkhart, Indiana 46517 U.S.A.

Phone: 1-219-294-8200

Fax: 1-219-294-8301

Toll Free in Canada, Puerto Rico, the United

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

Page 49

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

Crown Factory Ser vice Information

Shipping Address: Crown International, Inc., Factory Service, 57620 C.R. 105, Elkhart, Indiana 46517

Phone: 1-800-342-6939 or 1-219-294-8200 Fax: 1-219-294-8301

Owner’s Name:_________________________________________________________________________ Shipping Address:______________________________________________________________________ Phone Number: ________________________________________________________________________ Model: ________________________ Serial Number:______________ Purchase Date: ___________

NATURE OF PROBLEM

(Be sure to describe the conditions that existed when the problem occurred and what attempts were made to correct it.)

______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________

Detach and send with unit.

Other equipment in your system: _________________________________________________________

If warranty has expired, payment will be:

Card Number:___________________________ Exp. Date:_______ Signature:_____________________________

ENCLOSE THIS PORTION WITH THE UNIT. DO NOT MAIL SEPARATELY.

■ ■

■ Cash/Check

■ ■

■■

■ VISA

■■

■ MasterCard

■■

■ C.O.D.

■■

Page 49

Crown Com-Tech CT-1600, Com-Tech CT-400, Com-Tech CT-200, Com-Tech CT-800, Com-Tech 200 Reference Manual

Specifications and Main Features

Frequently Asked Questions

User Manual