Models: Macro-Tech 600, 1200 & 2400 Macro-Tech …inphase.at/documents/docs/marm.pdfFax:...

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Models:Macro-Tech 600, 1200 & 2400Macro-Tech 601, 1201 & 2401

Some models may be exported under the name Amcron.®

102989-17/97

© 1997 by Crown International, Inc., P.O. Box 1000, Elkhart, IN 46515-1000 U.S.A. Telephone: 219-294-8000.Fax: 219-294-8329. Macro-Tech amplifiers are produced by the Professional Audio Division of CrownInternational, Inc. Trademark Notice: SmartAmp™ and Grounded bridge™ are trademarks and Amcron,®

Crown,® Macro-Tech,® IOC,® ODEP,® IQ System,® P.I.P.® and TEF ® are registered trademarks of CrownInternational, Inc. Other trademarks are the property of their respective owners.

®

®CommercialAudioLL 32521C

120 VAC NorthAmerican

Units Only:

CommercialAudioE106377

Approved forTHX TheatreSystems

WORLDWIDESUMMARY OF WARRANTY

The Crown Audio Division of Crown International, Inc., 1718 WestMishawaka Road, Elkhart, Indiana 46517-4095 U.S.A. warrants to you,the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of eachNEW Crown1 product, for a period of three (3) years from the date ofpurchase by the original purchaser (the “warranty period”) that the newCrown product is free of defects in materials and workmanship, and wefurther warrant the new Crown product regardless of the reason forfailure, except as excluded in this Crown Warranty.1 Note: If your unit bears the name “Amcron,” please substitute it for thename “Crown” in this warranty.

ITEMS EXCLUDED FROM THIS CROWN WARRANTYThis Crown Warranty is in effect only for failure of a new Crown productwhich occurred within the Warranty Period. It does not cover any productwhich has been damaged because of any intentional misuse, accident,negligence, or loss which is covered under any of your insurancecontracts. This Crown Warranty also does not extend to the new Crownproduct if the serial number has been defaced, altered, or removed.

WHAT THE WARRANTOR WILL DOWe will remedy any defect, regardless of the reason for failure (exceptas excluded), by repair, replacement, or refund. We may not elect refundunless you agree, or unless we are unable to provide replacement, andrepair is not practical or cannot be timely made. If a refund is elected,then you must make the defective or malfunctioning product availableto us free and clear of all liens or other encumbrances. The refund willbe equal to the actual purchase price, not including interest, insurance,closing costs, and other finance charges less a reasonabledepreciation on the product from the date of original purchase. Warrantywork can only be performed at our authorized service centers. We willremedy the defect and ship the product from the service center withina reasonable time after receipt of the defective product at our authorizedservice center.

HOW TO OBTAIN WARRANTY SERVICEYou must notify us of your need for warranty service not later than ninety(90) days after expiration of the warranty period. All components must beshipped in a factory pack. Corrective action will be taken within areasonable time of the date of receipt of the defective product by ourauthorized service center. If the repairs made by our authorized servicecenter are not satisfactory, notify our authorized service centerimmediately.

DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGESYOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTALDAMAGES RESULTING FROM ANY DEFECT IN THE NEW CROWNPRODUCT. THIS INCLUDES ANY DAMAGE TO ANOTHER PRODUCTOR PRODUCTS RESULTING FROM SUCH A DEFECT.

WARRANTY ALTERATIONSNo person has the authority to enlarge, amend, or modify this CrownWarranty. This Crown Warranty is not extended by the length of timewhich you are deprived of the use of the new Crown product. Repairsand replacement parts provided under the terms of this Crown Warrantyshall carry only the unexpired portion of this Crown Warranty.

DESIGN CHANGESWe reserve the right to change the design of any product from time totime without notice and with no obligation to make correspondingchanges in products previously manufactured.

LEGAL REMEDIES OF PURCHASERNo action to enforce this Crown Warranty shall be commenced laterthan ninety (90) days after expiration of the warranty period.

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERSCONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.

9/90

NORTH AMERICASUMMARY OF WARRANTY

The Crown Audio Division of Crown International, Inc., 1718 West MishawakaRoad, Elkhart, Indiana 46517-4095 U.S.A. warrants to you, the ORIGINALPURCHASER and ANY SUBSEQUENT OWNER of each NEW Crown prod-uct, for a period of three (3) years from the date of purchase by the originalpurchaser (the “warranty period”) that the new Crown product is free of defectsin materials and workmanship. We further warrant the new Crown productregardless of the reason for failure, except as excluded in this Warranty.

ITEMS EXCLUDED FROM THIS CROWN WARRANTYThis Crown Warranty is in effect only for failure of a new Crown product whichoccurred within the Warranty Period. It does not cover any product which hasbeen damaged because of any intentional misuse, accident, negligence, orloss which is covered under any of your insurance contracts. This CrownWarranty also does not extend to the new Crown product if the serial numberhas been defaced, altered, or removed.

WHAT THE WARRANTOR WILL DOWe will remedy any defect, regardless of the reason for failure (except asexcluded), by repair, replacement, or refund. We may not elect refund unlessyou agree, or unless we are unable to provide replacement, and repair is notpractical or cannot be timely made. If a refund is elected, then you must makethe defective or malfunctioning product available to us free and clear of all liensor other encumbrances. The refund will be equal to the actual purchase price,not including interest, insurance, closing costs, and other finance charges lessa reasonable depreciation on the product from the date of original purchase.Warranty work can only be performed at our authorized service centers or atthe factory. We will remedy the defect and ship the product from the servicecenter or our factory within a reasonable time after receipt of the defectiveproduct at our authorized service center or our factory. All expenses inremedying the defect, including surface shipping costs in the United States,will be borne by us. (You must bear the expense of shipping the productbetween any foreign country and the port of entry in the United States and alltaxes, duties, and other customs fees for such foreign shipments.)

HOW TO OBTAIN WARRANTY SERVICEYou 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 shippedin 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 receiptof the defective product by us or our authorized service center. If the repairsmade by us or our authorized service center are not satisfactory, notify us orour authorized service center immediately.

DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGESYOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTALDAMAGES RESULTING FROM ANY DEFECT IN THE NEW CROWNPRODUCT. THIS INCLUDES ANY DAMAGE TO ANOTHER PRODUCT ORPRODUCTS RESULTING FROM SUCH A DEFECT. SOME STATES DONOT ALLOW THE EXCLUSION OR LIMITATIONS OF INCIDENTAL ORCONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OREXCLUSION MAY NOT APPLY TO YOU.

WARRANTY ALTERATIONSNo 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 aredeprived of the use of the new Crown product. Repairs and replacement partsprovided under the terms of this Crown Warranty shall carry only the unexpiredportion of this Crown Warranty.

DESIGN CHANGESWe reserve the right to change the design of any product from time to timewithout notice and with no obligation to make corresponding changes inproducts previously manufactured.

LEGAL REMEDIES OF PURCHASERTHIS CROWN WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, YOUMAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE TO STATE.No action to enforce this Crown Warranty shall be commenced later thanninety (90) days after expiration of the warranty period.

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERSCONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.

9/90Telephone: 219-294-8200. Facsimile: 219-294-8301Telephone: 219-294-8200. Facsimile: 219-294-8301

THREE YEARFULL WARRANTY YEAR

3YEAR3

The information furnished in this manual does not include all of the details of design, production, or variations ofthe equipment. Nor does it cover every possible situation which may arise during installation, operation or main-tenance. If your unit bears the name “Amcron,” please substitute it for the name “Crown” in this manual. If youneed special assistance beyond the scope of this manual, please contact our Technical Support Group.

Crown Audio Division Technical Support GroupPlant 2 SW, 1718 W. Mishawaka Rd., Elkhart, Indiana 46517 U.S.A.

Phone: 800-342-6939 (North America, Puerto Rico and Virgin Islands) or 219-294-8200Fax: 219-294-8301 Fax Back (North America only): 800-294-4094 or 219-293-9200

Fax Back (International): 219-294-8100 Internet: http://www.crownintl.com

IMPORTANTTHE MACRO-TECH 2400 REQUIRES CLASS 1OUTPUT WIRING. THE MACRO-TECH 600 &1200 REQUIRE CLASS 2 OUTPUT WIRING.

Printed onrecycled paper.

The lightning bolttriangle is used toalert the user to therisk of electric shock.

The exclamation pointtriangle is used to alert theuser to important operating ormaintenance instructions.

WARNINGTO REDUCE THE RISK OF ELECTRIC

SHOCK, DO NOT EXPOSE THISEQUIPMENT TO RAIN OR MOISTURE!

Magnetic FieldCAUTION! Do not locate sensitive high-gain equip-ment such as preamplifiers or tape decks directlyabove or below the unit. Because this amplifier hasa high power density, it has a strong magnetic fieldwhich can induce hum into unshielded devices thatare located nearby. The field is strongest just aboveand below the unit.

If an equipment rack is used, we recommend locatingthe amplifier(s) in the bottom of the rack and thepreamplifier or other sensitive equipment at the top.

C A U T I O NRISK OF ELECTRIC SHOCK

DO NOT OPEN

TO PREVENT ELECTRIC SHOCK DONOT REMOVE TOP OR BOTTOM

COVERS. NO USER SERVICEABLEPARTS INSIDE. REFER SERVICINGTO QUALIFIED SERVICE PERSON-NEL. DISCONNECT POWER CORDBEFORE REMOVING REAR INPUT

MODULE TO ACCESS GAIN SWITCH.

A V I SRISQUE DE CHOC ÉLECTRIQUE

N’OUVREZ PAS

À PRÉVENIR LE CHOC ÉLECTRIQUEN’ENLEVEZ PAS LES COUVERCLES.

IL N’Y A PAS DES PARTIESSERVICEABLE À L’INTÉRIEUR. TOUSREPARATIONS DOIT ETRE FAIRE PAR

PERSONNEL QUALIFIÉ SEULMENT.DÉBRANCHER LA BORNE AVANT

D’OUVRIR LA MODULE EN ARRIÈRE.

Macro-Tech 600/1200/2400 Power Amplifiers

CONTENTS1 Welcome ............................................................................ 7

1.1 Unpacking ................................................................... 71.2 Features ...................................................................... 7

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

3 Installation ....................................................................... 103.1 Mounting ................................................................... 103.2 Cooling ...................................................................... 103.3 Wiring ........................................................................ 11

3.3.1 Stereo (Two-Channel) Operation ..................... 113.3.2 Bridge-Mono Operation .................................. 123.3.3 Parallel-Mono Operation .................................. 133.3.4 Input Connection............................................. 143.3.5 Output Connection .......................................... 163.3.6 Additional Load Protection .............................. 18

3.4 AC Power Requirements ............................................ 18

4 Operation ......................................................................... 194.1 Precautions ............................................................... 194.2 Indicators .................................................................. 194.3 Protection Systems .................................................... 21

4.3.1 ODEP .............................................................. 214.3.2 Standby Mode ................................................ 214.3.3 Transformer Thermal Protection ...................... 214.3.4 Fuses and Circuit Breakers ............................. 22

4.4 Controls ..................................................................... 224.5 Filter Cleaning............................................................ 23

5 Technical Information ..................................................... 245.1 Overview ................................................................... 245.2 Circuit Theory ............................................................ 24

5.2.1 Stereo Operation ............................................. 245.2.2 Bridge-Mono Operation .................................. 265.2.3 Parallel-Mono Operation .................................. 26

6 Specifications ................................................................. 27

7 AC Power Draw & Thermal Dissipation .......................... 36

8 Accessories .................................................................... 389.1 P.I.P. Modules ............................................................ 389.2 Cooling Fan Options .................................................. 409.3 Level Control Security Kit ........................................... 40

9 Service ............................................................................. 419.1 Worldwide Service ..................................................... 419.2 North American Service ............................................. 41

9.2.1 Service at a N. American Service Center ........ 419.2.2 Factory Service ............................................... 41


ILLUSTRATIONS1.1 Macro-Tech Amplifier ................................................................ 72.1 Front Facilities ........................................................................... 82.2 Rear Facilities ........................................................................... 93.1 Mounting Dimensions ............................................................. 103.2 Top View of a Rack-Mounted Unit ........................................... 103.3 Proper Air Flow in a Rack Cabinet ........................................... 103.4 Stereo Wiring .......................................................................... 113.5 Bridge-Mono Wiring ................................................................ 123.6 Parallel-Mono Wiring ............................................................... 133.7 Unbalanced Input Wiring ........................................................ 143.8 Balanced Input Wiring ............................................................ 143.9 Balanced and Unbalanced Phone Plugs ................................ 143.10 Subsonic Filter Capacitors ...................................................... 153.11 Unbalanced RFI Filters ........................................................... 153.12 Balanced RFI Filters ................................................................ 153.13 Wire Size Nomograph ............................................................. 163.14 Inductive Load (Transformer) Network .................................... 173.15 Loudspeaker Fuse Nomograph .............................................. 184.1 Indicators................................................................................ 194.2 Macro-Tech ODEP and Signal/IOC Indicator States ................ 204.3 Input Sensitivity and Ground Lift Switches .............................. 225.1 Circuit Block Diagram ............................................................. 256.1 Macro-Tech 600 Minimum Power Matrix ................................. 296.2 Macro-Tech 1200 Minimum Power Matrix ................................ 306.3 Macro-Tech 2400 Minimum Power Matrix ................................ 306.4 Macro-Tech 600 Maximum Power Matrix ................................ 316.5 Macro-Tech 1200 Maximum Power Matrix .............................. 326.6 Macro-Tech 2400 Maximum Power Matrix .............................. 326.7 Typical Frequency Response .................................................. 336.8 Typical Damping Factor .......................................................... 336.9 Typical Output Impedance ...................................................... 336.10 Typical Phase Response ......................................................... 346.11 Typical Crosstalk for the Macro-Tech 600 ................................ 346.12 Typical Crosstalk for the Macro-Tech 1200 .............................. 356.13 Typical Crosstalk for the Macro-Tech 2400 .............................. 357.1 Macro-Tech 600 Power Draw, Current Draw and

Thermal Dissipation at Various Duty Cycles ............................ 367.2 Macro-Tech 1200 Power Draw, Current Draw and

Thermal Dissipation at Various Duty Cycles ............................ 377.3 Macro-Tech 2400 Power Draw, Current Draw and

Thermal Dissipation at Various Duty Cycles ............................ 378.1 Installing a P.I.P. Module .......................................................... 388.2 Installing an MA-LOCK Level Control Shaft Lock .................... 40


1 WelcomeCongratulations on your purchase of the renownedMacro-Tech® professional power amplifier. Macro-Techamplifiers are designed to provide enormous levels ofpure, undistorted power in a rugged low-profile pack-age—making them the choice for pro sound reinforce-ment. They utilize our patented ODEP® protectioncircuitry to keep the show going long after other ampli-fiers have shut down. And with their P.I.P.®

expandability, Macro-Tech amplifiers can be easily cus-tomized with one of our many optional input modules(see Section 8 for a list of available P.I.P.s.).

This manual will help you successfully install and useyour new amplifier. Please read all instructions, warn-ings and cautions. Be sure to read Sections 3.3.2 and3.3.3 if you plan to use one of the amplifier’s two monomodes. Also for your protection, please send in yourwarranty registration card today and save your bill ofsale because it is your official proof of purchase .

1.1 UnpackingPlease unpack and inspect your new amplifier for anydamage that may have occurred during transit. If dam-age is found, notify the transportation company imme-diately. Only you, the consignee, may initiate a claimfor shipping damage. Crown will be happy to cooper-ate fully as needed. Save the shipping carton as evi-dence 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 youever need to transport the unit. NEVER SHIP THE UNITWITHOUT THE FACTORY PACK.

1.2 FeaturesMacro-Tech amplifiers use cutting edge technology todeliver the ultimate in power and value for their size,weight and price. They offer numerous advantagesover conventional designs and provide benefits youcan’t get in amplifiers from any other manufacturer.

Here are some of their many features:

Crown’s grounded bridge design delivers large voltageswings without using easily stressed output transistorconfigurations like conventional amplifiers. The resultsare lower distortion and superior reliability.

Patented ODEP (Output Device Emulation Protection) cir-cuitry compensates for overheating and overload to keepthe amplifier working when others would fail.

IOC ® (Input/Output Comparator) circuitry immediatelyalerts of any distortion exceeding 0.05%, providing dy-namic proof of distortion-free performance.

P.I.P. (Programmable Input Processor) connector acceptsaccessories that tailor the amplifier to suit specific appli-cations.

Two mono modes (Bridge-Mono and Parallel-Mono) fordriving a wide range of load impedances.

Very low harmonic and intermodulation distortion result inthe best dynamic transfer function in the industry.

High damping factor provides superior control over lowfrequency drivers for a clean, accurate low end.

Full protection against shorted outputs, mismatchedloads, input/output DC, general overheating, high-fre-quency overloads and internal faults.

Dedicated power supply transformers isolate channels inStereo mode for superb crosstalk characteristics and reli-ability—each channel is virtually a separate amplifier.

Balanced inputs with internal three-position sensitivityswitch and adjustable front panel level controls.

Versatile 5-way binding posts make it easy to connectoutput wiring.

Ground lift switch isolates the AC power and phone jackaudio grounds.

Efficient heat sinks and a self-contained forced-air cool-ing system dissipate heat quickly and evenly for extraamplifier protection and greater power output.

Extra rugged, extruded aluminum front panel with ODEPand signal presence/IOC indicators for each channel,and an Enable Indicator.

Mounts in a standard 19 inch (48.3 cm) equipment rack(units can also be stacked).

Three year “No-Fault” full warranty completely protectsyour investment and guarantees its specifications.

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Fig. 1.1 Macro-Tech Amplifier


Fig. 2.1 Front Facilities

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A B C D D C B E F

2 FacilitiesA. Dust FiltersThe dust filters remove large particles from the airdrawn in by the cooling fan. Check the filters regularlyto prevent clogging. The filter elements can be easilyremoved for cleaning by gently pulling them away fromthe front panel (see Sections 3.2 and 4.5).

B. Level ControlsThe output level for each channel is set with these con-venient level controls mounted on the front panel. Eachlevel control has 31 detents for precise adjustment (seeSection 4.4). A security option is available to preventtampering (see Section 8.3).

C. Signal/IOC IndicatorsThese green multifunction indicators show signal pres-ence and distortion for each channel. As signal pres-ence indicators, they flash synchronously with theoutput audio signals to show their presence. As IOC(Input/Output Comparator) indicators, they flashbrightly with a 0.1 second hold delay if there is a differ-ence of 0.05% or more between the input and outputsignal waveforms. This provides proof of distortion-freeperformance. Another IOC function is to indicate inputoverload. If an input signal is too large, the indicator forthe affected channel flashes brightly with a 0.5 secondhold delay to show clipping distortion. Note: The Chan-nel 2 IOC indicator stays on in Parallel-Mono mode (seeSection 4.2).

D. ODEP IndicatorsDuring normal operation of the ODEP (Output DeviceEmulation Protection) circuitry, these amber indicatorsglow brightly to show the presence of reserve thermal-

dynamic energy. They dim proportionally as energy re-serves decrease. In the rare event that energy reservesare depleted, the indicators turn off and ODEP propor-tionally limits output drive so the amplifier can safelycontinue operating even under severe conditions.These indicators can also help identify more unusualoperating conditions (see Section 4.2).

E. Enable IndicatorThis indicator lights when the amplifier has been “en-abled” or turned on, and AC power is available (seeSection 4.2).

F. Enable SwitchThis push button is used to turn the amplifier on andoff. When turned on, the output is muted for approxi-mately four seconds to protect your system from start-up transients. (This delay can be changed. ContactCrown’s Technical Support Group for details.)

G. Power CordThe power cord has an appropriate plug for the re-quired voltage. 120 VAC, 60 Hz North American Macro-Tech 600s and 1200s have 14 AWG line cords andNEMA 5-15P plugs. Macro-Tech 2400s have 12 AWGline cords and NEMA 5-20P plugs. International unitsare shipped with an appropriate line cord and plug.See Section 7 for AC power usage.

H. Stereo/Mono SwitchThe three operating modes of a Macro-Tech amplifierare controlled by this switch. Stereo mode is used fornormal two-channel operation, Bridge-Mono mode is


Fig. 2.2 Rear Facilities

UNBALANCEDINPUT WIRING

BALANCEDINPUT WIRING

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

BRIDGE-MONO WIRINGTURN AMPLIFIER OFF.

SET STEREO/MONOSWITCH TOBRIDGE-MONO.

OUTPUT ACROSSRED TERMINALSONLY. (CH-1IS POSITIVE.)

PARALLEL-MONO WIRINGTURN AMPLIFIER OFF.

SET STEREO/MONOSWITCH TOPARALLEL-MONO.

ADD JUMPER (14GAGE OR LARGER)ACROSS REDTERMINALS.

OUTPUT ACROSS CH-1TERMINALS ONLY.

1

2

3

4

1

2

3

CH-2 CH-1

+

–

CH-2 CH-1 –

+

+–

TIP

RING

SLEEVEGND

INPUT GROUND LIFT

+ TIP

SLEEVEGND

(AFFECTS PHONE INPUTS ONLY.)CAUTION: TURN OFF AMPLIFIER

BEFORE CHANGING THIS SWITCH!

STEREO

BRIDGEMONO

PARALLELMONO

INPUTS

PUSH TO RESET

CLASS 1OUTPUTWIRING

REQUIRED.

WARNING: TO REDUCE THE RISK OF FIRE ORELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENTTO RAIN OR MOISTURE.

OUTPUTS

(MONO)LIFTREG. U.S. PAT. OFF.4,330,8094,611,180

MODEL: MACRO-TECH 2400 SERIES AC VOLTS: 120 AMPS: 17 60 Hz

MAXIMUM OUTPUT: 900 WATTSPER CHANNEL INTO 2 OHMS AT 1 KHzWITH NO MORE THAN 0.1% THD.

® INTERNATIONAL, INC.ELECTRONIC EQUIPMENT

ELKHART, IN 46517MADE IN U.S.A.

SERIAL NUMBER

0000

000000

PRESS

R E

SE

T

PRESS

R E

SE

T

ProgrammableInput Processor (P.I.P.)

3

1 2GNDI N P U T I N P U T

C H - 2 C H - 1

PUSH PUSH

FX

G H I J K M K ML N N

used to drive a single channel with a load impedanceof at least 4 ohms, and Parallel-Mono mode is used todrive a single channel with an impedance less than 4ohms. Important: Turn off the amplifier beforechanging the stereo/mono switch (see Section 3.3).

I. Reset Switches (Macro-Tech 2400 only)The Macro-Tech 2400 has a back panel Reset switchfor each channel. Each switch resets the circuit breakerthat protects the channel’s power supply from overload.

J. P.I.P. ModuleThe standard P.I.P.-FX is included with your amplifier. Itprovides female XLR input connectors. A variety ofother P.I.P. modules can be used in place of theP.I.P.-FX. They add additional features that customizethe amplifier for different applications (see Section 8.1for information on available P.I.P. modules).

Input Sensitivity SwitchThe three-position input sensitivity switch located in-side the amplifier can be set after removing the P.I.P.module (J). It is set at the factory to 0.775 volts forstandard 1 kHz output into 8 ohms. It can also be set to1.4 volts for standard 1 kHz output into 8 ohms, or afixed voltage gain of 26 dB (see Section 4.4).

K. Balanced Phone Jack InputsBalanced ¼-inch phone jack input connectors are pro-vided on the back panel of your amplifier. The phonejacks can be wired for either balanced (tip, ring and

sleeve) or unbalanced (tip and sleeve) input signals.Because they are electrically in parallel with the P.I.P.input connectors, input signals should not be con-nected to the phone jacks when certain P.I.P. modulesare installed (see Section 3.3.4). The phone jacks canalso be used as “daisy chain” outputs to simplify con-necting input signals to multiple amplifiers. Caution:The Channel 2 input should NOT be used in eithermono mode.

L. Ground Lift SwitchThis switch isolates or “lifts” the phone jack signalgrounds from the AC power ground. Activating theswitch inserts an impedance between the sleeve ofeach phone jack and the unit’s AC ground to help pre-vent the hum that can result from a ground loop.

M. Balanced XLR InputsThe factory-installed P.I.P.-FX provides a three-pin fe-male XLR connector for balanced input to each chan-nel. The XLR inputs are connected in parallel with theamplifier’s phone jack inputs. Because the P.I.P.-FXdoes not have any active circuitry, its XLR connectorscan also be used as “daisy chain” outputs to connectsignals from phone jack inputs to multiple amplifiers(see Section 3.3.4). Caution: The Channel 2 inputshould NOT be used in either mono mode.

N. Output JacksA pair of versatile 5-way binding posts is provided forthe output of each channel. The 5-way binding postsaccept banana plugs, spade lugs or bare wire.


If the air supply is unusually dusty, you might want topre-filter it using commercial furnace filters to preventrapid loading of the unit’s own air filter. When needed,the unit’s filter can be cleaned with mild dish detergentand water (see Section 4.5).

BLOWER(OPTION 2)

BLOWER(OPTION 1)

AIRFLOW

FRONTOF

RACK

DOOR

AIRFLOW

EQUIPMENTRACK

(SIDE VIEW)

Fig. 3.3 Proper Air Flow in a Rack Cabinet

3 Installation3.1 MountingMacro-Tech amplifiers are designed for standard19-inch (48.3 cm) rack mounting and “stack” mount-ing without a cabinet. For more efficient cooling andextra support in a rack, it is recommended that unitsbe stacked directly on top of each other.

Important: If the unit will be transported, it should alsobe securely supported at the back of the rack.

Fig. 3.2 Top View of a Rack-Mounted Unit

AIRFLOW

AIR FLOW

AMPLIFIER(TOP VIEW)

RACKCABINET

16 in40.6 cm

2 in(5 cm)MIN.

IMPORTANT: Be sure rear of amplifieris securely mounted to rack.

17 in43.2 cm

AIRFLOW

3.2 CoolingNEVER block the side or front air vents. Macro-Techamplifiers do not need to be mounted with space be-tween them. If you must leave open spaces in a rackfor any reason, close them with blank panels to pre-vent air from recycling into the front of other ampliers.Allow at least 35 cubic feet (1 cubic meter) per minuteper unit for the Macro-Tech 600 and 1200, and at least45 cubic feet (1.3 cubic meters) per minute per unit forthe Macro-Tech 2400. Additional air flow may be re-quired when driving low impedance loads at consis-tently high output levels. Refer to Section 7 for detailedinformation on thermal dissipation.

Fig. 3.1 Mounting Dimensions

19 in48.3 cm

16 in40.6 cm

3.5 in8.9 cm

2.5 in6.35 cm

SIDE VIEW

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When mounting the amplifier in a rack, the side walls ofthe rack should be at least 2 inches (5 cm) away fromthe chassis as shown in Figure 3.2.

Tip: An easy way to verify adequate cooling is to ob-serve the ODEP indicators while the amplifier is oper-ating under worst-case conditions. If the indicatorsdim, additional cooling is recommended.

If your rack has a front door that could block air flow tothe amplifier’s air intakes, you must provide adequateair flow by installing a grille in the door or by pressuriz-ing the air behind the door. Wire grilles are recom-mended over perforated panels because they tend tocause less air restriction. A good choice for pressuriz-ing the air behind a rack cabinet door is to mount a“squirrel cage” blower inside the rack (Option 1 be-low). At the bottom of the rack, mount the blower so itblows outside air into the space between the door andin front of the amplifiers, pressurizing the “chimney”behind the door. This blower should not blow air into ortake air out of the space behind the amplifiers. Forracks without a door, you can evacuate the rack bymounting the blower at the top of the rack so that airinside the cabinet is drawn out the back (Option 2 be-low).


3.3 WiringThis section describes the most common ways to in-stall your amplifier in a sound system. The input andoutput terminals are located on the back panel. Pleaseuse care when making connections, selecting signalsources and controlling the output level. The load yousave may be your own! Crown assumes no liability fordamaged loads resulting from careless amplifier useor deliberate overpowering.

CAUTION: Always remove power from the unit andturn the level controls off while making or chang-ing connections. This is very important when loud-speakers are connected because it reduces thechance of loud blasts that can cause loudspeakerdamage.

Macro-Tech amplifiers may be operated in one of threemodes (Stereo, Bridge-Mono, and Parallel-Mono) byswitching the stereo/mono switch on the back panel.There are VERY IMPORTANT wiring differences amongthese three modes which will be discussed next.

MIXER

CHANNEL 1LOUDSPEAKER

–

+

–

+

CHANNEL 2LOUDSPEAKER

CHANNEL 2

CHANNEL 1

STEREO MODE

Macro-Tech Amplifier

CH-2 CH-1

CH-2 CH-1

STEREO

BRIDGEMONO

PARALLELMONO

INPUTS

OUTPUTS

I N P U T I N P U T

C H - 2 C H - 1FX

CAUTION: TURN OFF AMPLIFIER BEFORE CHANGING THIS SWITCH!

STEREOBRIDGEMONO

PARALLELMONO

PUSH PUSH

PRESS

R E

SE

T

PRESS

R E

SE

T

Fig. 3.4 Stereo Wiring

3.3.1 Stereo (Two-Channel) OperationIn Stereo mode, installation is very intuitive: input Chan-nel 1 feeds output Channel 1, and input Channel 2feeds output Channel 2. To put the amplifier in Stereomode, first turn off the amplifier, then slide the stereo/mono switch to the center position, and properly con-nect the output wiring as shown in Figure 3.4. A pair of5-way binding posts is provided for each channel tofacilitate easy connection of loudspeaker wires. Ob-serve correct loudspeaker polarity and be very carefulnot to short the two outputs.

CAUTION: In Stereo mode, never parallel the twooutputs by directly tying them together, and neverparallel them with the output of another amplifier.Such a connection does not result in increased poweroutput, but may result in overheating and prematureactivation of the protection circuitry.

Note: A method for paralleling multiple amplifiers forfail-safe redundancy is available from Crown’s Techni-cal Support Group.


3.3.2 Bridge-Mono OperationBridge-Mono mode is intended for driving loads with atotal impedance of 4 ohms or more (see Section 3.3.3if the load is less than 4 ohms). Installing the amplifierin Bridge-Mono mode is very different from the othermodes and requires special attention.

To put the amplifier in Bridge-Mono mode, turn theamplifier off and slide the stereo/mono switch to theright (as you face the back of the amplifier). Both out-puts receive the signal from Channel 1 with the outputof Channel 2 inverted so it can be bridged with theChannel 1 output. DO NOT USE THE CHANNEL 2 IN-PUT or the signal level and quality may be greatly de-graded. Keep the Channel 2 level control turned downcompletely (counterclockwise).

Note: The input jack and level control of Channel 2 are

Fig. 3.5 Bridge-Mono Wiring

BRIDGE-MONO MODE

CH-2 CH-1

CH-2 CH-1

STEREO

BRIDGEMONO

PARALLELMONO

INPUTS

OUTPUTS

I N P U T I N P U T

C H - 2 C H - 1FX


STEREOBRIDGEMONO

PARALLELMONO

MIXER

–

+


LOUDSPEAKER

DO NOT USETHE CHANNEL 2

INPUTS.

DO NOTUSE BLACK

BINDINGPOSTS.

ONLY USE THE CHANNEL 1 INPUTS

PUSH PUSH

PRESS

R E

SE

T

PRESS

R E

SE

T

not defeated in Bridge-Mono mode. Any signal fed intoChannel 2 will work against and add to or distort thesignal in Channel 1.

Connect the load across the Channel 1 and 2 red bind-ing posts with the positive lead from the load attachingto the red post of Channel 1 and the negative lead ofthe load attaching to the red post of Channel 2 asshown in Figure 3.5. THE TWO BLACK BINDINGPOSTS ARE NOT USED AND SHOULD NOT BESHORTED. The load must be balanced (neither sideshorted to ground).

CAUTION: Be certain all equipment (meters,switches, etc.) connected to the mono output isbalanced. To prevent oscillations, both sides of theline must be isolated from the input grounds.


Fig. 3.6 Parallel-Mono Wiring

PARALLEL-MONO MODE

CH-2 CH-1

CH-2 CH-1

STEREO

BRIDGEMONO

PARALLELMONO

INPUTS

OUTPUTS

I N P U T I N P U T

C H - 2 C H - 1FX


STEREOBRIDGEMONO

PARALLELMONO

MIXER

ONLY USE THE CHANNEL 1 INPUTS


LOUDSPEAKER

ADD A 14 GAUGEOR LARGER

JUMPER BETWEENTHE CHANNEL 1AND 2 RED (+)

BINDING POSTS.

–

+

PUSH PUSH

THE CHANNEL 2INPUTS ARENOT USED.

PRESS

R E

SE

T

PRESS

R E

SE

T

3.3.3 Parallel-Mono OperationParallel-Mono mode is intended for driving loads with anet impedance of less than 4 ohms. (See Bridge-Monoif the load is 4 ohms or greater.) Installing the amp inParallel-Mono mode is very different from the othermodes and requires special attention.

CAUTION: Do not attempt to operate in Stereo orBridge-Mono mode until the Parallel-Mono jumperis first removed. Failure to do so will result in highdistortion and excessive heating.

To put the amplifier in Parallel-Mono mode, turn it offand slide the stereo/mono switch to the left (as youface the back panel). Connect the input signal to Chan-nel 1 only. The Channel 2 input and level control are

bypassed in this mode, so they should not be used.

Note: It is normal for the IOC indicator of Channel 2 tostay on in Parallel-Mono mode.

Install a jumper wire between the red binding posts ofboth Channel 1 and 2 that is at least 14 gauge in size.Then, connect the load to the output of Channel 1 asshown in Figure 3.6. The positive lead from the loadconnects to the red binding post of Channel 1 and thenegative lead from the load connects to the black bind-ing post of Channel 1.

CAUTION: Remove the jumper wire before chang-ing to Stereo or Bridge-Mono mode.


Tw

in-le

ad s

hiel

ded

cabl

e

2-wire line cord(or battery power)

Shield connectedto ground terminal

3-wire grounded line cord(or other ground connection)

Shield is notconnectedat this end

Groundedsource


Input groundterminal not used

Groundedsource

Sin

gle-

cond

ucto

r co

axor

twis

ted

pair2-wire line cord

(or battery power)

Floatingsource

Shield connected to bothnegative (–) and groundinput terminals

+–

INPUT

Output

Floatingsource

+

3

1 2

+–

INPUT

+Output

3

1 2

+–

INPUT

Output +

3

1 2

+–

+Output

INPUT

3

1 2

3.3.4 Input ConnectionBoth the balanced XLR and phone jack inputs have anominal impedance of 20 K ohms (10 K ohms with un-balanced wiring) and will accept the line-level outputof most devices. Female XLR input connectors are pro-vided on the standard P.I.P.-FX input module (otherP.I.P. modules are described in Section 8.1). Correctinput wiring will depend on two factors: (1) whether theinput signals are balanced or unbalanced, and (2)whether the signal source floats or has a ground refer-ence. Figures 3.7 and 3.8 show the recommendedconnection techniques for each type of signal source.

The amplifier’s built-in ¼-inch phone jack input con-nectors can be wired similarly for balanced or unbal-anced, floating or ground-referenced sources. They

Fig. 3.7 Unbalanced Input WiringFig. 3.9 Balanced and Unbalanced Phone Plugs

3

1 2

+–

INPUT

2-wire line cord(or battery power)

Note: If two or more channels withthe same input ground reference

are driven from the samefloating source, connect

only one shield to thesource chassis.

Floatingsource


Shield not connectedat this end

Groundedsource

3

1 2

Output+–

+–

Output+–

INPUT

Fig. 3.8 Balanced Input Wiring

have a standard tip-ring-sleeve (TRS) configuration:the tip is positive (+), the ring is negative (–) and thesleeve is ground (see Figure 3.9). Wiring for varioussources follows the XLR wiring guidelines shown in Fig-ures 3.7 and 3.8.

The phone jacks should not be used as inputs when aP.I.P. module with active circuitry is installed. The phonejacks are in parallel with the output of the P.I.P. module,so an input signal connected to the phone jacks canfeed backwards into the active circuitry of the P.I.P. andcause undesirable distortion. You can use the phonejacks for signal input with any of the following P.I.P.modules installed: P.I.P.-FX, P.I.P.-BB, P.I.P.-FMX, P.I.P.-FXQ and P.I.P.-FPX. All other P.I.P. modules have activecircuitry and should not be installed if you plan to con-nect input signals to the phone jacks. The phone jackscan always be used as “daisy chain” outputs to feedpost-processed signals from the P.I.P. to the inputs ofother amplifiers.

Please follow the instruction in Section 3.3.2 and 3.3.3if the amplifier will be used in either Bridge-Mono orParallel-Mono mode. Remember, do not use the Chan-nel 2 input in either mono mode.

+–

SHIELD

BALANCED

+

SHIELD

UNBALANCED


SOLVING INPUT PROBLEMSSometimes large subsonic (subaudible) frequenciesare present in the input signal. These can damageloudspeakers by overloading or overheating them. Toattenuate such frequencies, place a capacitor in se-ries with the input signal line. The graph in Figure 3.10shows some capacitor values and how they affect thefrequency response. Use only low-leakage paper,mylar or tantalum capacitors.

Input Wiring Tips

1. Use only shielded cable. Cables withhigher density shields are better. Spiralwrapped shield is not recommended.

2. When using unbalanced lines, keep thecables as short as possible. Avoid cablelengths greater than 10 feet (3 meters).

3. Do not run signal cables together withhigh-level wiring such as loudspeaker wiresor AC cords. This greatly lessens the chanceof hum or noise being induced into the inputcables.

4. Turn the entire system off before changingconnections. Turn level controls downcompletely before powering the system backup. Crown is not liable for damage incurredwhen any transducer or component isoverdriven.

+

–

Balanced In

910 Ω

.003fµ

.015fµ

.018fµ

1.8 mH

2.5 mH

A

C

B

.015fµ

1.8 mH

D

Balanced Out

+

–910 Ω

1.8 mH

2.5 mH

1.8 mH

+

–

Balanced In Balanced Out

+

–

+

–


+

–

+

–


+

–

0.47 Film

0.47 Film

Fig. 3.12 Balanced RFI Filters1 Hz 10 Hz 100 Hz 1 kHz 10 kHz

dB

0

–5

–10

–15

1 fµ .1 fµ.05 f .01 fµ µ

Frequenc y

Fig. 3.10 Subsonic Filter Capacitors

Another problem to avoid is the presence of large lev-els of radio frequencies or RF in the input signal. Al-though high RF levels may not pose a threat to theamplifier, they can burn out tweeters or other loads thatare sensitive to high frequencies. Extremely high RFlevels can also cause your amplifier to prematurelyactivate its protection circuitry, resulting in inefficientoperation. RF can be introduced into the signal by lo-cal radio stations and from the bias signal of many taperecorders. To prevent high levels of input RF, install anappropriate low-pass filter in series with the the inputsignal. Some examples of unbalanced wiring for low-pass filters are shown in Figure 3.11.

4 kHz 10 kHz 40 kHz 100 kHz

Frequenc y

dB

0

–10

–20

A

B

C

6 dB/octave

12 dB/octave

ToAmp

GND

ToAmp

GND

ToAmp

GND

Source

1.8 K ohm

.003fµ

.015fµ

.018fµ

3.9 mH

5 mH

600 ohmSource

R

600 ohmSource

R

A

C

B

Note: A low source impedance (R) can beincreased to 600 ohms with an a ppropriate resistor.

Fig. 3.11 Unbalanced RFI Filters

For balanced input wiring use one of the examples inFigure 3.12. Filters A, B and C correspond to the un-balanced filters above. Filter D also incorporates thesubsonic filter described previously.

Tip: The P.I.P.-FX included with your amplifier hasplenty of room on its circuit board for input filters.

A third problem to avoid is hum . The two most com-mon sources of hum in an audio system are inductivecoupling and ground loops .

Inductive coupling can occur when input cables aresubjected to a magnetic field from a power cord orpower transformer. One way to prevent inductive cou-pling is to lace the input cables together along theirlength and route them as far away as possible frompower transformers and power cords. The use of


shielded pair cable is another effective way to reduceor eliminate hum resulting from inductive coupling.

Ground loops often result when two or more devicesare improperly grounded. This causes undesirablestray currents that may produce hum in the output. Thebest way to avoid ground loops is to ensure that allsystem devices are plugged into the same power strip.In addition, make sure that all cable shields aregrounded at one end only.

Input and output grounds are sometimes tied togetherfor testing or metering. This can cause feedback os-cillation from load current in the test loop. In somesystems, even the AC power line may provide this feed-back path. Proper grounding, input isolation and isola-tion of common AC devices in the system is goodpractice.

3.3.5 Output ConnectionConsider the power handling capacity of your loadbefore connecting it to the amplifier. Crown is not liablefor damage incurred at any time due to overpowering.Fusing loudspeaker lines is highly recommended (seeSection 3.3.6). Also, please pay close attention to theprecautions provided in Section 4.1.

cable resistance increases. This is very important be-cause the amplifier’s excellent damping factor can eas-ily be negated by insufficient loudspeaker cables.

Use the nomograph in Figure 3.13 and the procedurethat follows to find the recommended wire gauge (AWGor American Wire Gauge) for your system.

Use Good Connectors

1. To prevent possible shorts, do not exposethe loudspeaker cable connectors.

2. Do not use connectors that might acci-dentally tie two channels together when mak-ing or breaking connections (for example, astandard three-wire stereo phone plug).

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

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

5. Connectors with any tendency to shortshould never be used.

HOW TO DETERMINEAPPROPRIATE WIRE GAUGE

It is important to use loudspeaker cables with sufficientgauge (thickness) for the length being used. The re-sistance introduced by inadequate loudspeakercables will reduce both the output power and the mo-tion control of the loudspeakers. The latter problemoccurs because the damping factor decreases as the

40

30

20

15

10

9

8

7

6

5

4

3

2

1

2

5

10

20

50

100

.04

.06

.1

.2

.4

.6

1

2

4

6

10

20

40

5

10

20

50

1

2

100

200

500

1000

2000

5000

8000

5000

1000

500

100

50

10

5

1

.5

.1

.05

.01

#28

#26

#24

#22

#20

#18

#16

#14

#12

#10

#8

#6

#4

#2

#0#00#0000

R

LOAD

RESISTANCE

(ohms)

L

R

R

DAMPING

FACTOR

L

S

R

SOURCE

RESISTANCE

(ohms)

S

2-COND.

CABLE

(feet)

COPPER

WIRE

(AWG)(ohms/1000 ft.)

Example Shown:R = 8 ohms; R = 0.016 ohms or D.F. = 500;Cable Length = 10 ft.; answer: #8 wire

L S

1

0.5

200

500

1,000

2,000

20,000

5,000

10,000

.01

.001

.02

.004

.006

.002

.0004

.0006

.0002

0.6

0.7

0.8

1.5

0.9

Fig. 3.13 Wire Size Nomograph


1. Note the load resistance of the loudspeakers connectedto each channel of the amplifier. 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 excel-lent damping factor of 1,000 from 10 to 400 Hz in Stereomode with an 8-ohm load. In contrast, typical damping fac-tors are 50 or lower. Higher damping factors yield lower dis-tortion and greater motion control over the loudspeakers. Acommon damping factor for commercial applications is be-tween 50 and 100. Higher damping factors may be desir-able for live sound, but long cable lengths often limit thehighest damping factor that can be achieved practically.(Under these circumstances, Crown’s IQ System® is oftenused so amplifiers can be monitored and controlled whenthey are located very near the loudspeakers.) In recordingstudios and home hi-fi, a damping factor of 500 or more isvery desirable.

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

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

5. Draw a pencil line from the mark on the “Source Resis-tance” 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 anddamping factor is the value on the “Annealed Copper Wire”line. Note: Wire size increases as the AWG gets smaller.

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 Sys-tem, (2) settle for a lower damping factor, or (3) use morethan one cable for each line. Options 1 and 2 will require thesubstitution of new values for cable length or damping factorin the nomograph. For option 3, estimate the effective wiregauge by subtracting 3 from the apparent wire gauge everytime 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 PROBLEMSSometimes high-frequency oscillations occur whichcan cause your amplifier to prematurely activate itsprotection circuitry and result in inefficient operation.The effects of this problem are similar to the effects ofthe RF problem described in Section 3.3.4. To preventhigh-frequency oscillations:

1. Lace together the loudspeaker conductors foreach channel; do not lace together the conduc-tors from different channels. This minimizes thechance that cables will act like antennas andtransmit or receive high frequencies that cancause oscillation.

2. Avoid using shielded loudspeaker cable.

3. Avoid long cable runs where the loudspeakercables from different amplifiers share a com-mon cable tray or cable jacket.

4. Never connect the amplifier’s input and outputgrounds together.

5. Never tie the outputs of multiple amplifiers to-gether.

6. Keep loudspeaker cables well separated frominput cables.

7. Install a low-pass filter on each input line (similarto the RF filters described in Section 3.3.4.

8. Install input wiring according to the instructionsin Section 3.3.4.

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

Inductive loads can appear as a short circuit at lowfrequencies. This can cause the amplifier to producelarge low-frequency currents and activate its protec-tion circuitry. Always take the precaution of installing ahigh-pass filter in series with the amplifier’s input wheninductive loads are used. A 3-pole, 18 dB per octavefilter with a –3 dB frequency of 50 Hz is recommended(depending on the application, an even higher –3 dBfrequency may be desirable). Such a filter is describedwith subsonic frequency problems in Section 3.3.4.

Another way to prevent the amplifier from prematurelyactivating its protection systems and to protect induc-tive loads from large low-frequency currents is to con-nect a 590 to 708 µF nonpolarized capacitor and4-ohm, 20-watt resistor in series with the amplifier’soutput and the positive (+) lead of the transformer. Thecircuit shown below uses components that are avail-able from most electronic supply stores.

Fig. 3.14 Inductive Load (Transformer) Network

4-ohm, 20-wattResistor

590 to 708 µf Capacitor120 VAC, N.P.

+

–

InductiveLoad

+

–

FromAmplifierOutput


3.3.6 Additional Load ProtectionMacro-Tech amplifiers generate enormous power. Ifyour loudspeakers do not have built-in protection fromexcessive power, it’s a good idea to protect them.Loudspeakers are subject to thermal damage fromsustained overpowering and mechanical damage fromlarge transient voltages. Special fuses can be used toprotect your loudspeakers in both cases.

Two different types of fuses are required for thermalprotection and voltage protection. Slow-blow fuses areusually selected to protect loudspeakers from thermaldamage because they are similar to loudspeakers inthe way they respond to thermal conditions over time.In contrast, high-speed instrument fuses like theLittlefuse 361000 series are used to protect loudspeak-ers from large transient voltages. The nomograph inFigure 3.15 can be used to select the properly ratedfuse for either type of loudspeaker protection.

Fig. 3.15 Loudspeaker Fuse Nomograph

1.0

1.2

1.4

1.6

2.5

3

4

5

6

7

8

9

10

12

14

16

20

25

30

20

15

10

8

6

5

4

3

2

1.5

1

.8

.6

.5

.4

.3

.2

.15

.1

.08

3000

2000

1500

1000

800

600

400

300

200

150

100

80

60

40

30

20

15

10

8

6

4

3

2

1.5

1

LOU

DS

PE

AK

ER

IMP

ED

AN

CE

(ohm

s)

FU

SE

(am

ps)

LOU

DS

PE

AK

ER

RA

TIN

G

PE

AK

MU

SIC

PO

WE

R(w

atts

)(T

ypic

ally

4 ti

mes

the

cont

inuo

us a

vera

ge p

ower

)

Answer: Fuse = 1.5 A

2

40

Example: Impedance = 8 ohms.Peak Power = 75 W

There are basically two approaches that can be takenwhen installing fuses for loudspeaker protection. Acommon approach is to put a single fuse in series withthe output of each channel. This makes installation con-venient because there is only one fuse protecting theloads on each output. The main disadvantage of thisapproach becomes obvious if the fuse blows becausenone of the loads will receive any power.

A better approach is to fuse each driver independently.This allows you to apply the most appropriate protec-tion for the type of driver being used. In general, low-frequency drivers (woofers) are most susceptible tothermal damage and high-frequency drivers (tweeters)are usually damaged by large transient voltages. Thismeans that your loudspeakers will tend to have betterprotection when the woofers are protected by slow-blow fuses and high-frequency drivers are protectedby high-speed instrument fuses.

3.4 AC Power RequirementsAll Macro-Tech amplifiers are shipped with an appro-priate line cord. When possible, use a power recep-tacle on a dedicated circuit and always make sure thatit can supply the correct voltage and curent. We do notrecommend operating your amplifier on voltagesgreater than 10% above or below the unit’s rated volt-age. For example, if your amplifer is rated for 120 VAC,the line voltage should not exceed 132 VAC. See Sec-tion 7 for power requirements under a variety of condi-tions.

All specifications in this manual were measured using120 VAC, 60 Hz power, unless otherwise noted. Speci-fications were derived using a voltage that is accurateto within 0.5% with THD less than 1.0% under all test-ing conditions. Performance variations can occur atother AC voltages and frequencies. In addition, lineregulation problems directly affect the output powerfrom the amplifier.


4 Operation4.1 PrecautionsMacro-Tech amplifiers are protected from internal andexternal faults, but you should still take the follow pre-cautions for optimum performance and safety:

1. Improper wiring for Stereo, Bridge-Mono andParallel-Mono modes can result in serious oper-ating difficulties. Refer to Section 3.3 for details.

2. WARNING: Do not change the position of thestereo/mono switch unless the amplifier is fir stturned off.

3. CAUTION: In Parallel-Mono mode, a jumper isused between the red (+) Channel 1 and 2 out-put binding posts. Be sure to remove thisjumper for Stereo or Bridge-Mono mode, other-wise high distortion and excessive heating willdefinitely occur. Check the stereo/mono switch onthe back panel for proper position.

4. Turn off the amplifier and unplug it fr om the A Cmains before removing the P.I.P. card.

5. Use care when making connections, selecting sig-nal sources and controlling the output level. Theload you save may be your own.

6. Do not short the ground lead of an output cable tothe input signal ground. This may form a groundloop and cause oscillations.

7. Operate the amplifier from AC mains of not morethan 10% variation above or below the selectedline voltage and only the specified line frequency.

8. Never connect the output to a power supply out-put, battery or power main. Such connectionsmay result in electrical shock.

9. Tampering with the circuitry by unqualified person-nel, or making unauthorized circuit changes invali-dates the warranty.

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

4.2 IndicatorsThe amber Enable indicator is provided to show thatthe amplifier has been turned on (or enabled), and thatits low-voltage power supply and forced-air coolingsystem are working. It does not indicate the status ofthe high-voltage power supplies. For example, the En-able indicator will remain lit during unusual conditionsthat would cause the amplifier’s protection systems to

LEVEL LEVEL

ON

OF

30

27

24

21

1815

12

9

6

3

0 ENABLECH1 CH2

ODEP

30

27

24

219

6

3

0

SIGNAL/ IOC

1815

12

Fig. 4.1 Indicators

put a high-voltage power supply in “standby” mode(see Section 4.3).

The amber ODEP indicators confirm the normal op-eration of Crown’s patented Output Device EmulationProtection circuitry. During normal operation, they glowbrightly to show the presence of reserve thermal-dy-namic energy. They dim proportionally as the energyreserve decreases. In the rare event that there is noreserve, the indicators turn off and ODEP proportion-ally limits the drive level of the output stages so theamplifier can continue safe operation even when con-ditions are severe. (For a more detailed description ofODEP, see Section 4.3.1.)

The ODEP indicator for the affected channel will turnoff if a high-voltage power supply is put in “standby”mode, a high-voltage power supply fuse (or breaker)blows, or a transformer activates its thermal protectioncircuitry (see Section 4.3.2). Both ODEP indicators turnoff if the amplifier loses AC power, the power switch isturned off or the low-voltage power supply fuse blows.

The green Signal/ IOC indicators show signal pres-ence, distortion and input overload. As signal presenceindicators, they flash with normal intensity in sync withthe output audio signals. As IOC (Input/Output Com-parator) indicators, they flash brightly if there is anydifference between the input and output signal wave-forms greater than 0.05%. Because transient distor-tion happens quickly, a 0.1 second “hold delay” keepsthe indicators on long enough to be easily noticed. TheIOC function essentially provides proof of distortion-free performance. As input overload indicators, theyflash brightly with a 0.5 second hold delay to show thatan input signal is too large and must be clipped at theinput. Note: The Channel 2 IOC indicator will stay on inParallel-Mono mode.

Under abnormal conditions where one of the ampli-fier’s high-voltage power supplies is temporarily put instandby mode, the Signal/IOC indicators will stay onwith full brightness. They will resume normal operationwhen the amplifier is no longer in standby mode.


The table in Figure 4.2 shows the possible states forthe ODEP and Signal/IOC indicators. It also describesthe conditions that may be associated with the differ-ent indicator states. The Enable indicator will be off withthe first indicator state, “There is no power to the ampli-fier.” All other conditions in the table will occur with the

Enable indicator turned on. It is important to note thepossible states of the indicators in the rare event thatyou experience a problem. This can greatly aid in de-termining the source of problems. Please contact yourlocal Crown representative or our Technical SupportGroup for futher assistance.

Fig. 4.2 Macro-Tech ODEP and Signal/IOC Indicator States

ODEP

SIGNAL / IOC

OFF

OFF

There is no power to the amplifier and all indicators are off, including the Enable light. Possible reasons: (1) The amplifier’s Enable switch is off. (2) The amplifier is not plugged into the power receptacle. (3) The AC circuit breaker has been tripped. (4) The amplifier’s low-voltage power supply fuse has blown.

Indicator Status Amplifier Condition

ODEP

SIGNAL / IOC

ON

OFF

Normal operation for a channel with NO audio output. Possible reasons: (1) There is no input signal.(2) The input signal level is very low. (3) The channel’s level control is turned down.

ODEP

SIGNAL / IOC

ON

Normal

Normal operation for a channel with audio output. The ODEP indicator will remain at full intensityto show that there is reserve thermodynamic energy, and the Signal/IOC indicator will flash with normalintensity to show that the channel has audio output.

ODEP

SIGNAL / IOC

ON

Bright

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

ODEP

SIGNAL / IOC

OFF

Bright

The amplifier channel is in standby mode. Possible reasons: (1) A P.I.P. module like anIQ–P.I.P.–SMT has turned off the channel’s high-voltage power supply. (2) The amplifier has just beenturned on and is still in the four second turn-on delay. (3) The DC / low-frequency protection circuitry hasbeen activated. (4) The fault protection circuitry has been activated. (5) The transformer thermalprotection circuitry has been activated.

ODEP limiting has been activated. Possible reasons: (1) The amplifier’s air filters are blocked andneed 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 isdriving too many loudspeakers for the selected stereo/mono mode. (4) The amplifier channel iscontinuously being driven to very high output levels.

ODEP

SIGNAL / IOC

OFF

Normal

ODEP limiting is about to begin. Possible reasons: (1) The amplifier’s air filters are blocked and needto 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 isdriving too many loudspeakers for the selected stereo/mono mode. (4) The amplifier channel iscontinuously being driven to very high output levels.

OR

OR

OR

Channel 2 only: The amplifier is in Parallel-Mono mode. The channel 2 Signal/IOC indicator alwaysturns on to full brightness whenever the amplifier's stereo/mono switch is set to Parallel-Mono mode.

A channel’s fuse has blown or breaker has tripped. Transformer overload can cause a channel’sinternal fuse for its high-voltage supply to blow in a Macro-Tech 600 or 1200, and it cancause the channel’s circuit breaker to trip in a Macro-Tech 2400.


and put the affected channels in standby. This protectsthe loads and prevent oscillations. The unit resumesnormal operation as soon as the amplifier no longerdetects dangerous low frequency or DC output. Al-though it is extremely unlikely that you will ever activatethe amplifier’s DC/low-frequency protection system,improper source materials such as subsonic squarewaves or input overloads that result in excessivelyclipped input signals can activate this system.

The amplifier’s fault protection system will put an am-plifier channel in standby mode in rare situations whereheavy common-mode current is detected in thechannel’s output. The amplifier should never outputheavy common-mode current unless its circuitry isdamaged in some way, and putting a channel instandby mode helps to prevent further damage.

The amplifier’s transformer thermal protection cir-cuitry is activated in very unusual circumstances wherethe unit’s transformer temperature rises to unsafe lev-els. Under these abnormal conditions, the amplifier willput the channel of the affected transformer in standbymode. The amplifier will return to normal operation af-ter the transformer cools to a safe temperature. (Formore information on transformer thermal protection, re-fer to the following section.)

4.3.3 Transformer Thermal ProtectionAll Macro-Tech amplifiers have transformer thermalprotection. It protects the power supplies from dam-age under the rare conditions of transformer tempera-tures rising too high. A thermal switch embedded ineach transformer removes power to the channel if thereis excessive heat. The switch automatically resetswhen the transformer cools to a safe temperature.

It is extremely unlikely that you will ever see aMacro-Tech amplifier activate transformer thermal pro-tection as long as it is operated within rated conditions(see Section 6, Specifications). One reason is thatODEP keeps the amplifier working under very severeconditions. Even so, higher than rated output levels,excessively low impedance loads and unreasonablyhigh input signals can generate more heat in the trans-former than in the output devices. These conditionscan overheat the transformer and activate its protec-tion system.

Macro-Tech amplifiers are designed to keep workingunder conditions where other amplifiers would fail. Buteven when the limits of a Macro-Tech amplifier are ex-ceeded, it will still protect itself—and your investment—from damage.

4.3 Protection SystemsMacro-Tech amplifiers provide extensive protectionand diagnostics capabilities. Protection systems in-clude ODEP, “standby” mode, fuses (or breakers), andspecial thermal protection for the unit’s transformers.

4.3.1 ODEPCrown invented ODEP to solve two long-standing prob-lems in amplifier design: to prevent amplifier shutdownduring demanding operation and to increase the effi-ciency of the output circuitry.

To do this, Crown established a rigorous program tomeasure the safe operating area (SOA) of each outputtransistor before installing it in an amplifier. Next, Crowndesigned intelligent circuitry to simulate the instanta-neous operating conditions of those output transistors.Its name describes what it does: Output Device Emu-lation Protection or ODEP. In addition to simulating theoperating conditions of the output transistors, it alsocompares their operation to their known SOA. If it seesthat more power is about to be asked of them than theyare capable of delivering under the present conditions,ODEP immediately limits the drive level until it fallswithin the SOA. Limiting is proportional and kept to anabsolute minimum—only what is required to preventoutput transistor damage.

This level of protection enables Crown to increase out-put efficiency to never-before-achieved levels whilegreatly increasing amplifier reliability.

The on-board intelligence is monitored in two ways.First, the front panel ODEP indicators show whetherthe amplifier is functioning correctly or if ODEP is limit-ing the drive level. Second, ODEP data is fed to theback panel P.I.P. connector so advanced P.I.P. mod-ules like the IQ-P.I.P. can use it to monitor and controlthe amplifier.

With ODEP, the show keeps going because you getthe maximum power with the maximum protection.

4.3.2 Standby ModeAt the heart of the protection systems is the standbymode which removes power from the high-voltage sup-plies to protect the amplifier and connected loads. Thestandby mode can be identified using the indicatortable in Figure 4.2.

Standby mode can be activated in several situations.First, if dangerous subsonic frequencies or direct cur-rent (DC) is detected in the amplifier’s output, the unitwill activate its DC/low-frequency protection circuitry


4.3.4 Fuses and Circuit BreakersThe power supplies of the Macro-Tech 600 and 1200are protected by fuses. The power supplies of theMacro-Tech 2400 are protected by circuit breakers.With rated loads and output levels, the fuses (or circuitbreakers) should only shut down the amplifier in therare instance of a catastrophic failure. Other protectionsystems like ODEP keep the amplifier operational un-der most other severe conditions. The fuses (or circuitbreakers) can also shut down the amplifier in caseswhere extremely low-impedance loads and high out-put levels result in current draw that exceeds their rat-ing. Again, this should only be possible when operatingoutside rated conditions, like when the amplifier is usedto drive a 1-ohm load in Stereo mode, or when a signaloverloads the input and is clipped severely.

All 120 VAC, 60 Hz units and all Macro-Tech 2400shave a separate fuse for the low-voltage power supplyand cooling fan. All units have separate fuses or break-ers for the high-voltage power supplies.

Macro-Tech amplifiers do not blow their fuses or triptheir breakers unless something is wrong. In the rareevent that an internal fuse blows, please refer the unitto a qualified technician. If a breaker in a Macro-Tech2400 trips, try to identify and correct the problem be-fore resetting the breakers with the back panel Resetswitches . If the problem persists, refer the unit to aqualified technician.

4.4 ControlsThe Enable switch is located on the front panel so youcan easily turn the amplifier on and off. If you ever needto make any wiring or installation changes, don’t forgetto disconnect the power cord. The six steps listed nextshould be followed whenever you turn on the amplifier:

1. Turn down the level of your audio source. Forexample, set your master mixer’s volume to –∞.

2. Turn down the level controls of the amplifier (if theyare not already down).

3. Turn on the Enable switch. The Enable indicatorbeside the switch should glow. During the foursecond mute delay which immediately follows, theSignal/IOC indicators will flash unpredictably andthe ODEP LEDs will stay off. After the mute delay,the ODEP indicators should come on with fullbrilliance and the Signal/IOC indicators shouldfunction normally (remain off if no signal is present;flash if a signal is present). Remember, the Channel2 Signal/IOC indicator will remain on if the amplifieris in Parallel-Mono mode.

4. After the mute delay, turn up the level of your audiosource to the maximum desired level.

5. Turn up the level controls of the amplifier until themaximum desired sound level is achieved.

6. Turn down the level of your audio source to itsnormal range.

For ease of use, the level controls are also located onthe front panel. Each control has 31 detents for accu-rate repeatability. To prevent tampering with these con-trols, the Level Control Security Kit is available (seeSection 8.3). Note: In Bridge-Mono and Parallel-Monomodes, turn down the Channel 2 level control and onlyuse the Channel 1 control.

The input sensitivity switch is located inside the backpanel of the amplifier. It is factory-set to 0.775 volts forstandard 1 kHz power into 8 ohms. It can be switchedto 1.4 volts for standard 1 kHz power output or a fixedvoltage gain of 26 dB. When set 26 dB gain, the inputsensitivity is 2.2 volts for the Macro-Tech 600, 2.6 voltsfor the Macro-Tech 1200 and 3.1 volts for the Macro-Tech 2400.

How to change the input sensitivity:

1. Turn off the amplifier and disconnect its power cordfrom the AC mains power receptacle.

2. Remove the P.I.P. module (two screws).

3. Locate the sensitivity switch access hole inside thechassis opening as shown in Figure 4.3. It islocated just above the phone jack inputs.

4. Set the switch to the desired position noted on thelabel for the access hole. The position toward thefront panel sets the sensitivity to 1.4 volts forstandard 1 kHz power, the middle positionprovides 26 dB gain, and the back position sets the

0.77 V26 dB

SENSITIVITY SWITCH INSIDE ACCESS HOLE

GROUND LIFT SWITCH

1.4 V

UNBALANCEDINPUT WIRING

BALANCEDINPUT WIRING

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

CH-2 CH-1

+–

TIP

RING

SLEEVEGND

+ TIP

SLEEVEGND

INPUTS

(MONO)

INPUT GROUND LIFT

(AFFECTS PHONE INPUTS ONLY.)

LIFT

Fig. 4.3 Input Sensitivity and Ground Lift Switches


sensitivity to 0.775 volts for standard 1 kHz power.

5. Replace the P.I.P. module and reconnect the powerto the amplifier.

The Ground Lift switch is located on the back paneland can provide isolation between the input signalgrounds and the AC (chassis) ground. It affects onlythe phone jack inputs and has no affect on the P.I.P.module input connectors. Sliding the switch to the leftisolates or “lifts” the grounds by placing an impedancebetween the sleeve of each input phone jack and theAC power ground.

The noninverted and inverted signal lines for the P.I.P.module are connected in parallel with the correspond-ing lines of the phone jack inputs. The input signalgrounds are not paralleled. Specifically, XLR pins 2 and3 are connected in parallel with the tip and ring of thecorresponding phone jack. However, pin 1 of the XLRis not connected in parallel with the sleeve of the phonejack. This makes it possible for a P.I.P. module to handleits own signal grounds independently.

The Macro-Tech 2400 has back panel Reset switchesthat are used to reset the breakers that protect the high-voltage power supplies from overload. If a breakertrips, the IOC indicator for the affected channel will turnon (see Figure 4.2).

4.5 Filter CleaningDust filters are provided on the air intakes to the cool-ing system (see Figure 2.1). If these filters becomeclogged, the unit will not cool as efficiently as it shouldand may produce output levels that are lower than nor-mal due to high heat sink temperature.

To clean, remove each of the filter elements by gentlypulling them away from the front panel. Clean with milddishwashing detergent and warm water. Replacementfilters may be ordered from the factory.

Dust filters are not 100% efficient—depending on thelocal environment, the internal heat sinks of the ampli-fier will benefit from periodic cleaning by a qualifiedtechnician. Internal cleaning information is availablefrom our Technical Support Group.


The two channels may be used together to double thevoltage (Bridge-Mono) or the current (Parallel-Mono)presented to the load. This feature gives you flexibilityto maximize the power available to the load.

A wide bandwidth, multiloop design is used for state-of-the-art compensation. This produces ideal behaviorand results in ultra-low distortion values.

Aluminum extrusions have been widely used for heatsinks in power amplifiers due to their low cost and rea-sonable performance. However, measured on a wattsper pound or watts per volume basis, the extrusiontechnology doesn’t perform nearly as well as the heatsink technology developed for Macro-Tech amplifiers.

Our heat sinks are fabricated from custom convolutedfin stock that provides an extremely high ratio of areato volume, or area to weight. All power devices aremounted directly to massive heat spreaders that areelectrically at the Vcc potential. Electrifying the heatspreaders improves thermal performance by eliminat-ing the insulating interface underneath the power de-vices. The chassis itself is even used as part of thethermal circuit to maximize utilization of the availablecooling resources.

5.2 Circuit TheoryEach channel is powered by its own power transformerT100 or T200. Both channels share a common low-voltage transformer TF-1. The secondary output ofT100 is full-wave rectified by D109 and is filtered by alarge computer grade capacitor. D104 through D107provide boosted voltage to power LVAs and predrivers.A thermal switch embedded in each transformer pro-tects it from overheating.

The low-voltage transformer TF-1 uses a separatewinding on the fan motor. The TF-1 output is rectifiedby diodes D1, D2, D3 and D4 to generate an unregu-lated 24 volts. Monolithic regulators U1 and U2 providea regulated ±15 volts.

5.2.1 Stereo OperationFor simplicity, the discussion of Stereo operation willrefer to one channel only. Mono operation will be dis-cussed later.

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

The input signal at the phone jack passes directly intothe balanced gain stage (U104-C and U104-D). Whenthe P.I.P. module is used, the input signal first passesthrough the P.I.P.’s circuitry and then to the balancedgain stage.

5 Technical Information5.1 OverviewYour Macro-Tech amplifier incorporates several newtechnological advancements including real-time com-puter simulation of output transistor stress, low-stressoutput stages, an advanced heat sink embodimentand the Programmable Input Processor (P.I.P.) expan-sion system.

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

Real-time computer simulation is used to create ananalogue of the junction temperature of the output tran-sistors (hereafter referred to as “output devices”). Cur-rent is limited only when the device temperaturebecomes excessive (and by the minimum amount re-quired). This patented approach is called Output De-vice Emulation Protection (or ODEP). It maximizes theavailable output power and protects against overheat-ing—the major cause of device failure.

The amplifier is protected from all common hazardsthat plague high-power amplifiers including shorted,open or mismatched loads; overloaded power sup-plies, excessive temperature, chain-destruction phe-nomena, input overload and high-frequency blowups.The unit protects loudspeakers from input and outputDC, as well as turn-on and turn-off transients.

The four-quadrant topology used in a Macro-Tech’sgrounded output stages is called the grounded bridge.This patented topology makes full use of the powersupplies providing peak-to-peak voltages to the loadthat are twice the voltage seen by the output devices(see Figure 5.1).

As its name suggests, the grounded bridge topologyis referenced to ground. Composite devices are con-structed to function as gigantic NPN and PNP devicesto handle currents which exceed the limits of availabledevices. Each output stage has two composite NPNdevices and two composite PNP devices.

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


Fig. 5.1 Circuit Block Diagram

FAUL

T

ON

LY O

NE

CH

AN

NE

L S

HO

WN

NP

N H

IO

UT

PU

TS

TA

GE

NP

N L

OW

OU

TP

UT

ST

AG

E

PN

P L

OW

OU

TP

UT

ST

AG

E

PN

P H

IO

UT

PU

TS

TA

GE

+

OU

TP

UT

+Vcc

–Vcc

TR

AN

SLA

TO

R

LVA

LVA+V

cc

–Vcc

BIA

SC

UR

RE

NT

LIM

IT

TR

AN

SLA

TO

R

BA

LAN

CE

INP

UT

ST

AG

E

P.I.

P.

BA

LAN

CE

D

INP

UT

S 1/4"

PH

ON

E

XLR

VA

RIA

BLE

GA

IN S

TA

GE

ER

RO

RA

MP

DIS

PLA

Y

BIA

S

BR

IDG

EB

ALA

NC

E

+Vcc

–Vcc

POW

ERSU

PPLY

CON

TRO

LDC

/LF

TIM

ER

OD

EP

A B

A(O

DE

P)

B(O

DE

P)

D E

(DIS

PLA

Y)

DC

(DIS

PLA

Y)

E

HS

TE

MP

C(O

DE

P)

ENAB

LE

POW

ER

+Vcc

–Vcc

SUPP

LY


The balanced gain stage (U104-C and U104-D)causes balanced to single-ended conversion using adifference amplifier. From there, gain can be controlledwith a potentiometer. The error amp (U104-A) amplifiesthe difference between the output signal and the inputsignal from the gain pot, and drives the voltage trans-lator stage.

From the error amp U104-A, the voltage translatorstage channels the signal to the Last Voltage Amplifi-ers (LVAs) depending on the signal polarity. The +LVA(Q104 and Q105) and the –LVA (Q110 and Q111), withtheir push-pull effect through the bias servo Q318,drive the fully complementary output stage.

The bias servo Q318 is thermally coupled to the heatsink, and sets the quiescent bias current in the outputstage to lower the distortion in the crossover region ofthe output signal. Depending on the polarity of the out-put signal, D301, D302, D303 and D304 are used toremove the charge on the unused portion of the outputstage.

With the voltage swing provided by the LVAs, the sig-nal then gains current amplification through theDarlington emitter-follower output stage.

The bridge-balanced circuit (U104-B) receives a sig-nal from the output of the amplifier, and differences itwith the signal at the Vcc supply. The bridge-balancedcircuit then develops a voltage to drive the bridge-bal-anced output stage. This results in the Vcc supply hav-ing exactly one half of the output voltage added to theirquiescent voltage. D309, D310, D311 and a trimmerresistor set the quiescent current point for the bridge-balanced output stage.

The protection mechanisms that affect the signal pathare implemented to protect the amplifier under real-world conditions. These conditions are high instanta-neous current, excessive temperature, and outputdevice operation outside safe conditions.

Q107 and Q108 sense current in the output stage andact as a conventional current limiter. When current atany one instant exceeds the design criteria, the limit-ers remove the drive from the LVAs, thus limiting cur-rent in the output stage to a safe level.

To further protect the output stages, the patentedODEP circuitry is used. It produces an analog outputproportional to the always changing safe operatingarea of the output transistor. This output controls thetranslator stage previously mentioned, removing anyfurther drive that may exceed the safe operating areaof the output stage.

Thermal sensor S100 gives the ODEP circuits vital in-formation on the operating temperature of the heat sinkon which the output devices are mounted.

Should the amplifier fail in such a way that would causeDC across the output leads, the DC protection circuitsenses this on the negative feedback loop and shutsdown the power supply until the DC is removed.

5.2.2 Bridge-Mono OperationBy setting the back panel stereo/mono switch toBridge-Mono, the user can convert the Macro-Tech intoa bridged, single-channel amplifier. With a signal ap-plied to the Channel 1 input jack and the load con-nected across the red (+) back panel 5-way bindingposts, twice the voltage can be output.

The Channel 1 output feeds the Channel 2 error ampU204-A. Because there is a net inversion, the chan-nel 2 output is out of polarity with Channel 1. This pro-duces twice as much voltage across the load. Each ofthe channel’s protection mechanisms work indepen-dently if a fault occurs.

5.2.3 Parallel-Mono OperationWith the stereo/mono switch set to Parallel-Mono, theoutput of Channel 2 is paralleled with the output ofChannel 1. A suitable jumper capable of handling highcurrent levels must be connected across the red (+)5-way binding posts to gain the benefits of this modeof operation.

The signal path for Channel 1 is the same as previ-ously discussed, except Channel 1 also drives the out-put stage of Channel 2. The Channel 2 balanced input,error amp, translators and LVAs are disconnected andno longer control the Channel 2 output stage. Discon-necting the front-end stages from the Channel 2 outputcauses the Channel 2 IOC circuit to note that the inputwaveform (which is not present) does not match theoutput waveform (which is driven by the Channel 1 in-put signal). This activates the Channel 2 IOC indicatorany time the amplifier is switched to Parallel-Mono. TheChannel 2 output stage and protection mechanismsare also coupled through S1 and function as one.

In Parallel-Mono mode, twice the current of one chan-nel alone can be obtained. Because the Channel 2ODEP circuit is coupled through S1, this gives addedprotection if a fault occurs in the Channel 2 outputstage. The ODEP circuit of Channel 2 will limit the out-put of both output stages by removing the drive fromthe Channel 1 translator stages.


6 SpecificationsThe following applies to units in Stereo mode with 8-ohm loads and aninput sensitivity of 26 dB gain unless otherwise specified.

Standard 1 kHz Power: refers to maximum average power in watts at1 kHz with 0.1% THD.

Full Bandwidth Power: refers to maximum average power in wattsfrom 20 Hz to 20 kHz with 0.1% THD.

120 VAC, 60 Hz Units: refers to amplifiers with dedicated transform-ers for 120 VAC, 60 Hz power mains.

International Units: refers to amplifiers with special multi-tap trans-formers that are configurable for several AC mains voltages and linefrequencies (some are labeled 601, 1201 and 2401).

PerformanceFrequency Response: ±0.1 dB from 20 Hz to 20 kHz at 1watt (see Figure 6.7).

Phase Response: ±10 degrees from 10 Hz to 20 kHz at 1watt (see Figure 6.10).

Signal-to-Noise Ratio: A-weighted, better than 105 dBbelow full bandwidth power. Better than 100 dB below fullbandwidth power from 20 Hz to 20 kHz.

Total Harmonic Distortion (THD): Less than 0.05% at fullbandwidth power from 20 Hz to 1 kHz increasing linearlyto 0.1% at 20 kHz.

Intermodulation Distortion (IMD): (60 Hz, 7 kHz) Lessthan 0.05% from 163 milliwatts to full bandwidth power.

Damping Factor: Greater than 1,000 from 10 Hz to 400Hz (see Figure 6.8).

Crosstalk: See Figures 6.11, 6.12 and 6.13.

Slew Rate: Greater than 13 volts per microsecond.

Voltage Gain: 20:1 ±3% or 26 dB ±0.25 dB at the maxi-mum level setting (also see Section 4.4).

Macro-Tech 600: 54:1 ±12% or 35 dB ±0.5 dB at 0.775 voltsensitivity; 30:1 ±12% or 30 dB ±0.5 dB at 1.4 volt sensitivity.



PowerOutput Power: The following are guaranteed minimumsfor standard 1 kHz power from 120 VAC, 60 Hz NorthAmerican units. For more information or specs on interna-tional units, see the power matrices that follow.

Macro-Tech 600Stereo mode (both channels driven):

400 watts into 2 ohms.325 watts into 4 ohms.220 watts into 8 ohms.

Bridge-Mono mode:750 watts into 4 ohms.655 watts into 8 ohms.450 watts into 16 ohms.

Parallel-Mono mode:700 watts into 1 ohm.665 watts into 2 ohms.450 watts into 4 ohms.









Load Impedance: Safe with all types of loads. Rated for 2to 16 ohms in Stereo, 4 to 16 ohms in Bridge-Mono and 1to 4 ohms in Parallel-Mono mode.

Required AC Mains: 50/60 Hz; 100, 120, 220, 230 and240 VAC (±10%) units are available. All draw 100 watts orless at idle. Current, voltage and frequency requirementsare provided on the unit’s back panel (also see Section 7).

Amplifiers don’t create energy. The AC mains voltage andcurrent must be sufficient to deliver the power you expect.

ControlsEnable: A front panel push button used to turn the ampli-fier on and off.

Level: A front panel rotary control for each channel with 31detents used to control the output level.


Stereo/Mono: A three-position back panel switch used toselect Stereo, Bridge-Mono or Parallel-Mono mode.

Sensitivity: A three-position switch inside the P.I.P. com-partment used to select the input sensitivity for both chan-nels: 0.775 volts or 1.4 volts for standard 1 kHz power, or a26 dB voltage gain.

Ground Lift: A two-position back panel switch for isolat-ing the phone jack input grounds from the AC ground.

Reset (Macro-Tech 2400 only): A back panel push but-ton for each channel used to reset the circuit breaker thatprotects each power supply.

IndicatorsEnable: This amber front panel indicator shows the on/offstatus of the low-voltage power supply.

Signal/ IOC: Each channel has a green front panel indica-tor that flashes to show amplifier output. If a channel’s out-put waveform differs from its input by 0.05% or more, theindicator flashes brightly to show distortion. This functionprovides proof of distortion-free performance. In Parallel-Mono mode, the Channel 2 light stays on (see Section 4.2).

ODEP: Each channel has an amber front panel indicatorthat shows thermal-dynamic energy reserve. Normally,each ODEP indicator is lit to show available reserve en-ergy. In the rare event that a channel has no reserve, itsindicator will dim in proportion to ODEP limiting. An ODEPindicator may also turn off under other conditions (see Sec-tion 4.2).

Input/OutputInput Connector: Two balanced 1¦4-inch phone jacks onthe back panel and two balanced three-pin female XLRconnectors on the factory-installed P.I.P.-FX (see Section 8for information on optional P.I.P. modules).

Input Impedance: Nominally 20 K ohms, balanced. Nomi-nally 10 K ohms, unbalanced.

Input Sensitivity: Settings include 0.775 volts or 1.4 voltsfor standard 1 kHz power, or a 26 dB voltage gain (seeSection 4.4 for more information).

Output Connectors: Two sets of color-coded 5-way bind-ing posts (for banana plugs, spade lugs or bare wire).

Output Impedance: Less than 10 milliohms in series withless than 2 microhenries (see Figure 6.9).

DC Output Offset: (Shorted input) ±10 millivolts.

Output SignalStereo: Unbalanced, two-channel.

Bridge-Mono: Balanced, single-channel. Channel 1 con-trols are active; Channel 2 should not be used.

Parallel-Mono: Unbalanced, single-channel. Channel 1controls are active; Channel 2 controls are bypassed.

ProtectionMacro-Tech amplifiers are protected against shorted, openor mismatched loads; overloaded power supplies; exces-sive temperature, chain destruction phenomena, inputoverload damage and high-frequency blowups. They alsoprotect loudspeakers from input/output DC and turn-on/turn-off transients.

If unreasonable operating conditions occur, the patentedODEP circuitry will proportionally limit the drive level toprotect the output transistor stages, particularly in the caseof elevated temperature. Transformer overheating will re-sult in a temporary shutdown of the affected channel; whenit has cooled to a safe temperature, the transformer willautomatically reset itself. Controlled slew-rate voltage am-plifiers prevent RF burnouts. And input overload protec-tion is provided by current-limiting resistance at the input.Refer to Section 4.3.

Turn On: Four-second delay with no dangerous transients.Contact Crown’s Technical Support Group to change theturn-on delay time.

ConstructionSteel chassis with durable black finish, aluminum frontpanel with Lexan overlay, and specially designed flow-through ventilation from front to side panels.

Cooling: Internal heat sinks with forced-air cooling forrapid, uniform heat dissipation.

Dimensions: Standard 19 inch (48.3 cm) rack mountwidth (EIA RS-310-B), 3.5 inch (8.9 cm) height, 16 inch(40.6 cm) depth behind the mounting surface and 2.5 inch(6.35 cm) protrusion in front of the mounting surface.

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

120 VAC, 60 Hz Units:Macro-Tech 600: 39 pounds, 9 ounces (17.9 kg) net;44 pounds (19.9 kg) shipping weight.Macro-Tech 1200: 44 pounds, 1 ounce (20.0 kg) net;47 pounds (21.3 kg) shipping weight.Macro-Tech 2400: 51 pounds, 12 ounces (23.5 kg) net;65 pounds (29.5 kg) shipping weight.

International Units:Macro-Tech 600: 41 pounds, 15 ounces (19.0 kg) net;46 pounds (20.9 kg) shipping weight.Macro-Tech 1200: 42 pounds, 12 ounces (19.4 kg) net;46 pounds, 13 ounces (21.3 kg) shipping weight.Macro-Tech 2400: 48 pounds, 15 ounces (22.2 kg) net;57 pounds, 6 ounces (26.0 kg) shipping weight.


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.

Minim um Guaranteed P ower SpecificationsCrown’s minimum power specifications represent the absolute smallest amount of output power you can expect from youramplifier when it is driven to full output under the given conditions. Some spaces in each matrix may be left blank because thesame guarantee is not provided for those conditions—however, your amplifier will perform well under all conditions listed ineach matrix.

When measuring power, 0.1% THD appears to be the industry standard for distortion. Two of the maximum average powerspecifications shown in each minimum power matrix are measured at 0.1% THD so you can easily compare Crown specifica-tions 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 spec at 0.05% THD is included in each minimum power matrix which representsnon-clipped conditions. Although most manufacturers do not give you power specifications at 0.05% THD, we encouragethem to provide these specifications so you will have a more realistic representation of the way amplifiers should be used inthe 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 morethan 20% in output! A 100 watt amplifier would meet their specification if it only produced 79.4 watts. Other manufacturersqualify their specs by saying they are “typical,” “subject to manufacturing tolerances,” “single channel driven” or that they arespecified with “fuses bypassed.” Each of these statements effectively removes any performance guarantee. In fact, somemanufacturers use these tactics to generate large power numbers, and they don’t even print a disclaimer. We take a differentapproach at Crown—our amplifiers are guaranteed to meet or exceed their specifications for three years. Further, becauseour published specs are set below our “in-house” measurements, you can expect every Crown amplifier to exceed its pub-lished minimum power specs. We believe you should get what you pay for.

8

2

Macro-Tech 600 – Minimum Guaranteed Power (Watts)

Stereo-MonoMode

Stereo(both channels

driven)

Bridge-Mono(balanced output)

Parallel-Mono

1

16

4

4

FTC Continuous AverageAt 0.1% THD(See note 4)

1 kHz 20Hz-20kHz

Maximum Average

Load

(Ohm

s)

AC M

ains

120

VAC,

60

Hz U

nits

1 kHz

At 0.1% THD(See note 1)


400

325

225

750

655

450

700

665

450

380

335

230

730

680

465

680

665

460

20Hz-20kHz

4

2

8

8

2Stereo

(both channelsdriven)


Parallel-Mono

1

16

4

4


1 kHz

4

2

8

Inte

rnat

iona

l Uni

ts

335

300

210

650

605

425

305

220

625

440

395

325

220

745

650

445

695

660

450

375

330

230

725

670

465

675

665

455

320

220

645

450

635

450

320

230

645

465

645

455

285

210

570

420

285

215

565

430

Fig. 6.1 Macro-Tech 600 Minimum Power Matrix

Minimum Power Notes:All minimum power specifications are based on0.1% regulated AC mains and an ambient roomtemperature of 70° F (21° C). International unitswith multi-tap transformers are specified for theworst-case transformer tap (normally 100 VAC,50 Hz). The standard EIA power measurement(RS-490) is not identified here because it is iden-tical to the FTC Continuous Average Powerspecification.

1. A 1 kHz sine wave is presented to the ampli-fier and the output monitored for nonlineardistortion. The level is increased until the THDreaches 0.1%. At this level the averagepower per channel is reported.

2. A sine wave is presented to the amplifier overthe range from 20 Hz to 20 kHz and the out-put monitored for nonlinear distortion. Thelevel at each frequency is increased until theTHD reaches 0.1%. At this level the averagepower per channel is reported.

3. A 1 kHz sine wave is presented to the ampli-fier and the output monitored for nonlineardistortion. The level is increased until the THDreaches 0.05%. At this level the averagepower per channel is reported.

4. Continuous power in the context of FederalTrade Commission testing is understood tobe a minimum of five minutes of operation.Harmonic distortion is measured as the RMSsum total and given as a percentage of thefundamental output voltage. This applies forall wattages greater than 0.25 watts.


8

2


Stereo-MonoMode


driven)


Parallel-Mono

1

16

4

4


1 kHz 20Hz-20kHz

Maximum Average

Load

(Ohm

s)

AC M

ains

120

VAC,

60

Hz U

nits

1 kHz



1050

800

520

2070

1585

1035

2080

1605

1035

895

745

510

1775

1485

1030

1765

1470

1020

20Hz-20kHz

4

2

8

8

2Stereo



Parallel-Mono

1

16

4

4


1 kHz

4

2

8

Inte

rnat

iona

l Uni

ts

850

750

505

1670

1485

1000

715

500

1420

1000

1025

785

510

2030

1565

1020

2050

1590

1025

875

735

510

1735

1475

1020

1750

1460

1010

770

505

1530

1005

1470

1005

690

505

1395

1010

1400

1000

685

495

1355

955

660

500

1320

980

8

2


Stereo-MonoMode


driven)


Parallel-Mono

1

16

4

4


1 kHz 20Hz-20kHz

Maximum Average

Load

(Ohm

s)

AC M

ains

120

VAC,

60

Hz U

nits

1 kHz



675

480

310

1300

970

620

1300

965

620

520

420

285

1045

845

570

1040

845

570

20Hz-20kHz

4

2

8

8

2Stereo



Parallel-Mono

1

16

4

4


1 kHz

4

2

8

Inte

rnat

iona

l Uni

ts

585

450

295

1130

895

590

455

385

275

920

780

540

660

480

305

1285

960

615

1290

960

615

515

415

285

1030

840

565

1040

845

570

475

305

960

620

950

610

410

280

830

570

820

565

425

295

850

585

365

265

730

535




Maximum Power SpecificationsCrown’s maximum power specifications represent the largest amount of output power you can expect from your amplifierwhen it is driven to full output under the given conditions. These specifications can be used to prevent loudspeaker andhearing damage.

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

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

8

2Stereo



Parallel-Mono

1

16

4

4

460

350

255

820

700

510

905

765

520

450

375

260

945

745

520

880

740

525

4

2

8

8

2Stereo



Parallel-Mono

1

16

4

4

4

2

8

Macro-Tech 600 – Maximum Power (Watts)

Stereo-MonoMode

40 Millisecond Tone BurstAt 0.05% THD(See note 2)

Single Cycle Tone BurstAt less than 0.05% THD

(See note 1)

50 Hz 1 kHzLoad

(Ohm

s)

20 Hz 50 Hz 1 kHz 7 kHz 7 kHz

AC M

ains

120

VAC,

60

Hz U

nits

Inte

rnat

iona

l Uni

ts

460

430

280

910

860

565

920

865

560

495

475

310

970

950

620

915

960

610

475

575

325

930

1165

655

940

1155

650

505

615

350

985

1240

700

930

1230

700

495

560

320

940

1130

640

970

1120

635

515

605

345

990

1210

680

970

1225

675

460

375

245

910

750

510

920

750

510

490

415

270

970

825

545

915

845

540

430

340

235

855

685

465

860

690

465

460

370

250

915

730

500

895

735

505

455

355

245

895

710

485

890

710

485

490

385

260

960

770

525

940

765

530

Fig. 6.4 Macro-Tech 600 Maximum Power Matrix

Maximum Power Notes:All maximum power specifications arebased on 0.1% regulated AC mainsand an ambient room temperature of70° F (21° C). International units withmulti-tap transformers are specifiedfor the best-case transformer tap (nor-mally 240 VAC, 60 Hz). Although it isan unusual condition, your amplifiercan function well with AC mains volt-ages up to 10% over the specified linevoltage. With overvoltage conditions,your amplifier may be capable of de-livering instantaneous power levels upto 20% greater than the specificationsin the matrix.

1. A single cycle sine wave is pre-sented to the amplifier and moni-tored for nonlinear distortion. Theaverage power during the burst isreported. Loudspeakers must beable to withstand this level if theyare to be safely used with this am-plifier.

2. A 40 millisecond sine wave burst(10 percent duty cycle) is pre-sented to the amplifier and moni-tored for nonlinear distortion. Theaverage power during the burst isreported. This power level is ameasurement of the amplifier’smaximum transient power that canbe perceived by the human ear.


8

2Stereo



Parallel-Mono

1

16

4

4

685

515

350

1475

1030

675

1325

1010

690

635

490

330

1255

990

655

1240

975

655

4

2

8

8

2Stereo



Parallel-Mono

1

16

4

4

4

2

8


Stereo-MonoMode



(See note 1)

50 Hz 1 kHzLoad

(Ohm

s)


AC M

ains

120

VAC,

60

Hz U

nits

Inte

rnat

iona

l Uni

ts

885

620

375

1730

1240

745

1735

1230

750

850

620

385

1650

1255

765

1635

1250

765

1050

770

420

2025

1585

870

1980

1515

830

1075

810

440

2090

1615

880

1980

1605

890

1060

750

410

1945

1640

890

2010

1465

810

1090

785

425

2120

1565

850

1995

1555

855

755

535

345

1475

1120

695

1495

1060

675

755

550

350

1495

1105

695

1485

1075

685

685

500

320

1395

1040

665

1340

980

630

640

485

320

1265

980

640

1250

965

645

725

525

335

1395

1120

695

1405

1030

660

680

505

335

1330

1020

670

1315

1005

665

8

2Stereo



Parallel-Mono

1

16

4

4

1015

780

565

2010

1590

1120

1960

1565

1125

1025

835

570

2055

1670

1165

2035

1665

1135

4

2

8

8

2Stereo



Parallel-Mono

1

16

4

4

4

2

8


Stereo-MonoMode



(See note 1)

50 Hz 1 kHzLoad

(Ohm

s)


AC M

ains

120

VAC,

60

Hz U

nits

Inte

rnat

iona

l Uni

ts

1405

965

600

2745

1915

1185

2780

1955

1185

1485

1085

690

3000

2165

1395

2965

2160

1375

1715

1310

710

3380

2610

1420

3145

2605

1410

1655

1515

825

3390

3055

1675

3065

3040

1655

1675

1270

690

3380

2550

1375

3045

2505

1365

1680

1480

800

3335

2935

1610

3085

2945

1600

1250

860

545

2465

1775

1085

2510

1695

1125

1340

975

625

2660

1950

1245

2645

1940

1235

1090

795

510

2175

1590

1025

2145

1580

1020

1080

835

565

2140

1670

1145

2155

1685

1125

1145

830

535

2265

1660

1065

2225

1630

1060

1135

875

585

2250

1740

1190

2235

1735

1170




10 100 1 K 10 K 100 K

FREQUENCY (Hz)

+2

+1

0

–1

–2

–3

–4

dB

–5

–6

–7

4 ohm8 ohm1 watt

504.0

126.8

31.8

MILLIOHMS

8.0

2.0

6 dB

20 100 1 K 10 K 20 K

400

200

100

0

600

800

1000

1200

1400

FREQUENCY (Hz)

8 ohm

10 100 1 K 10 K 100 K

FREQUENCY (Hz)

2 ohm

Fig. 6.7 Typical Frequency Response

Fig. 6.8 Typical Damping Factor

Fig. 6.9 Typical Output Impedance


TECHRON TEF ®

+45˚

0˚

–45˚

100 1 K 10 K 20 K

FREQUENCY (Hz)

100 1 K 10 K 20 K

FREQUENCY (Hz)

dB

TECHRON TEF ®

TEF®Measurement

Fig. 6.11 Typical Crosstalk for the Macro-Tech 600

TEF®Measurement

–51

–57

–63

–69

–75

–81

Fig. 6.10 Typical Phase Response


100 1 K 10 K 20 K

FREQUENCY (Hz)

dB

TECHRON TEF ®

100 1 K 10 K 20 K

FREQUENCY (Hz)

dB

TECHRON TEF ®


–66

–72

–78

–84

–90

–96

–102

TEF ®Measurement


–60

–66

–72

–78

–84

–96

–90

TEF®Measurement


7 AC Power Draw and Thermal DissipationThis section provides detailed information about theamount of power and current drawn from the AC mainsby the Macro-Tech 600, 1200 and 2400 amplifiers andthe amount of heat produced under various conditions.The calculations presented here are intended to pro-vide a realistic and reliable depiction of the amplifiers.The following assumptions or approximations weremade:

• The amplifier’s available channels are loaded and fullpower is being delivered.

• The amplifier efficiency at standard 1 kHz power isestimated to be 65%.

• Quiescent power draw is 90 watts (an almost negli-gible amount for full-power calculations).

• Quiescent thermal dissipation equals 105 btu/hr at90 watts.

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

• Duty cycle of pink noise is 50%.

• Duty cycle of highly compressed rock ‘n’ roll mid-range is 40%.

• Duty cycle of rock ‘n’ roll is 30%.

• Duty cycle of background music is 20%.

• Duty cycle of continuous speech is 10%.

• Duty cycle of infrequent, short duration paging is 1%.

Here are the equations used to calculate the data pre-sented in Figures 7.1 through 7.3:

AC Mains PowerDraw (watts)

=

Total output power will allchannels driven (watts)

x DutyCycle

Amplifier Efficiency (.65)+ Quiescent Power

Draw (watts)

The quiescent power draw of 90 watts is a maximumvalue and includes power drawn by the fan. The fol-lowing equation converts power draw in watts to cur-rent draw in amperes:

Current Draw(amperes)

=

AC Mains PowerDraw (watts)

xAC MainsVoltage

PowerFactor (.83)

The power factor of 0.83 is needed to compensate forthe difference in phase between the AC mains voltageand current. The following equation is used to calcu-late thermal dissipation:

Total output power with allchannels driven (watts)

ThermalDissipation

(btu/hr)= +

Quiescent PowerDraw (watts)

x DutyCycle

Amplifier Efficiency (.65)( )x 3.415.35x

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

Total measured output powerfrom all channels (watts)

ThermalDissipation

(btu/hr)= +

Quiescent PowerDraw (watts)

.35x

Amplifier Efficiency (.65)( )x 3.415

8 Ohm Stereo

L O A D

50%

40%

30%

20%

10%

450

380

305

235

160

740

655

565

480

395

615

510

405

300

195

235

205

170

140

110

720

595

470

340

215

1060

910

760

610

460

4.5

3.8

3.1

2.4

1.6

6.1

5.1

4.0

3.0

1.9

7.2

6.0

4.7

3.4

2.2

DutyCycle

AC MainsPowerDraw

(Watts) btu/hr

Current Draw (Amps)

2.3

1.9

1.6

1.2

0.8

3.1

2.6

2.0

1.5

1.5

3.6

3.0

2.4

1.7

1.1

4 Ohm Stereo / 8 Ohm Bridge-Mono / 2 Ohm Parallel-Mono 2 Ohm Stereo / 4 Ohm Bridge-Mono / 1 Ohm Parallel-Mono

Macro-Tech 600

185

165

140

120

100

kcal

930

805

680

560

435

265

230

190

155

115

100-120 V 220-240 V

Thermal Dissipation

btu/hr

Current Draw (Amps)

kcal100-120 V 220-240 V

Thermal Dissipation

btu/hr

Current Draw (Amps)

kcal100-120 V 220-240 V

Thermal DissipationAC MainsPowerDraw

(Watts)

AC MainsPowerDraw

(Watts)

Fig. 7.1 Macro-Tech 600 Power Draw, Current Draw andThermal Dissipation at Various Duty Cycles


8 Ohm Stereo

L O A D

50%

40%

30%

20%

10%

580

485

385

285

190

895

780

660

545

425

850

700

545

395

240

310

260

215

170

125

1165

950

735

520

305

1595

1335

1080

820

565

5.8

4.8

3.9

2.9

1.9

8.5

7.0

5.5

3.9

2.4

11.7

9.5

7.4

5.2

3.1

DutyCycle

AC MainsPowerDraw

(Watts) btu/hr

Current Draw (Amps)

2.9

2.4

2.0

1.5

1.0

4.3

3.5

2.8

2.0

1.2

5.9

4.8

3.7

2.6

1.6


Macro-Tech 1200

225

195

165

135

105

kcal

1220

1035

855

670

490

400

335

270

205

140

100-120 V 220-240 V

Thermal Dissipation

btu/hr

Current Draw (Amps)

kcal100-120 V 220-240 V

Thermal Dissipation

btu/hr

Current Draw (Amps)

kcal100-120 V 220-240 V


(Watts)

AC MainsPowerDraw

(Watts)

8 Ohm Stereo

L O A D

50%

40%

30%

20%

10%

890

730

570

410

250

1265

1070

880

690

500

1320

1075

830

580

335

450

375

300

225

150

1780

1445

1105

765

430

2330

1925

1520

1115

710

8.9

7.3

5.7

4.1

2.5

13.2

10.8

8.3

5.8

3.4

17.8

14.4

11.1

7.7

4.3

DutyCycle

AC MainsPowerDraw

(Watts) btu/hr

Current Draw (Amps)

4.5

3.7

2.9

2.1

1.3

6.6

5.4

4.2

2.9

1.7

8.9

7.2

5.6

3.9

2.2


Macro-Tech 2400

320

270

220

175

125

kcal

1780

1485

1190

895

600

585

485

385

280

180

100-120 V 220-240 V

Thermal Dissipation

btu/hr

Current Draw (Amps)

kcal100-120 V 220-240 V

Thermal Dissipation

btu/hr

Current Draw (Amps)

kcal100-120 V 220-240 V


(Watts)

AC MainsPowerDraw

(Watts)




8 Accessories8.1 P.I.P. ModulesOne advantage of Macro-Tech amplifiers is the abilityto customize them using P.I.P. (Programmable InputProcessor) and PIP2 modules. Macro-Tech amplifiersare equipped with an edge card connector inside theback panel P.I.P. compartment. The modules installeasily:

FTE


CH-2 INPUT CH-1 INPUT+ – + –

P.I.P.–FTE uses balanced 1:1 transformers to isolate the ampli-fier from the input signal. It also includes 12 dB/octave RFI fil-ters, 18 dB/octave high pass filters, and 6 dB/octave 3 kHzshelving networks for “constant-directivity” horn equalization.Screw terminal plugs are provided for input.

DSPI

AUX

CH-2 CH-1AUDIO IN3

2 1

GND GND

32

1 1

2

IN OUTCROWNBUS

GND OUTIN

3

2

1

MEM#.###

P.I.P.-MEMPUSH PUSH

IQ–P.I.P.–MEM is PIP2-compatible and integrates the amplifierinto Crown’s patented IQ System®. The IQ System providescomputer control of 1 to 2000 amplifiers. For example, eachamplifier channel can be monitored and controlled from a per-sonal computer attached to an IQ System. A memory backupfeature enables the IQ–P.I.P.–MEM to remember all configura-tion settings when the power is turned off.

P.I.P.-SMT DSPI

AUX

CH-2 CH-1AUDIO IN3

2 1

GND GND

32

1 1

2

IN OUTCROWNBUS

GND OUTIN

3

2

1

PUSH PUSH

SMT#.###

IQ–P.I.P.–SMT is also PIP2-compatible and includes all the fea-tures of the IQ–P.I.P.–MEM plus SmartAmp™ capability. Oncethe unit has been configured by an IQ System, its SmartAmpcapabilities enable it to function autonomously. We call this dis-tributed intelligence™. The SmartAmp features include a smoothoutput limiter for transparent loudspeaker protection, powersupply gates for energy savings, ODEP conservation to pro-tect output devices with precision input signal control, inter-rupt-driven reporting that lets you define error conditions, andconfigurable short circuit detection.

P.I.P.-DSPPUSHPUSH

DSPI

CH-2 CH-1

EXT. POWER INPUT24 VDC / 400 mA

TIP= RING =

IN OUTCROWNBUS

AUDIO OUT

3

2 1

GND CH-2 CH-1AUDIO IN DSP#.###

IQ–P.I.P.–DSP is PIP2-compatible and provides digital signalprocessing capabilities to your amplifier, replacing the need foroutboard signal processing equipment such as equalizers,crossover networks, signal delays and compressors. In addi-tion, the IQ–P.I.P.–DSP includes all the SmartAmp features ofthe IQ–P.I.P.–SMT to give you access to standard IQ Systemamplifier functions and autonomous operation.

WARNING: Disconnect power to the amplifier wheninstalling or removing a P.I.P. module.

P.I.P.s carrying the PIP2 logo are configured to use oneor more of the PIP2 enhanced features. These featuresare only available in a PIP2-compatible amplifier. Ofcourse, the exact features used will depend upon thefunction of the PIP2 module. Here are some of the avail-able P.I.P. and PIP2 modules:

AMC


O U T P U T I N P U T3

1 2GND

PUSH

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 crossoverand an IOC-driven, variable threshold compressor. In addi-tion, it provides “constant-directivity” horn equalization andfilter-assisted B6 vented box equalization. Biamping andtriamping capabilities are provided via XLR connectors.


I N P U T3

1 2GND

PUSH

C H - 2 C H - 1

PUSH

I N P U T

EDCb

P.I.P.–EDCb combines a sophisticated error-driven compres-sor and smooth limiter with a maximum level setting and asubsonic filter for each channel. The compressors have ad-justable attack and release times, and can be set to trackeach other. The compressors activate when a signal wouldotherwise clip the input, an IOC error occurs, or the outputexceeds the selected threshold. The subsonic filters havecorner frequencies of 24, 28, 32 and 36 Hz.

P.I.P.MODULE

BACK PANEL

OF AMPLIFIER

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


CLP


3

1 2GNDI N P U T I N P U T

C H - 2 C H - 1

PUSH PUSH

P.I.P.–CLP detects and prevents overload. Its compressor isdriven by the amplifier’s built-in IOC error detection circuitry.Unlike typical signal-driven compressors, it only compressesthe signal to prevent overload. It can deliver up to 13 dB ofadditional headroom without being noticeable.

ISO


—WARNING—THIS P.I.P. PROVIDES FULL ISOLATIONFOR ISO-MODIFIED AMPLIFIERS ONLY!

DO NOT CONNECT THE OUTPUT GROUNDLUG TO THE INPUT COMMON OR CHASSISGROUND. REFER TO P.I.P.–ISO OWNER’SMANUAL FOR FURTHER INFORMATION.

+ –CH-2 INPUT

+ –CH-1 INPUT

P.I.P.–ISO is designed especially for 25 to 140 volt distrib-uted systems where UL®-listed isolation is required. Installa-tion requires minor amplifier modifications. With the P.I.P.–ISOinstalled, the amplifier outputs are safely isolated from theinput terminals and the chassis.


+ – –ATTENUATION ATTENUATIONATNB

C H - 2 I N P U T C H - 1 I N P U T

0dB.5

1234

56

7810121416

1820222428

60∞ 0dB.5

1234

56

7810121416

1820222428

60∞

+

P.I.P.–ATNB uses balanced 1:1 transformers to isolate theamplifier from the input signal. It also includes 12 dB/octaveRFI filters, variable 18 dB/octave high-pass filters, and 6 dB/octave 3 kHz shelving networks for “constant-directivity” hornequalization. The module also includes a calibrated 21-stepprecision attenuator for each channel. Screw terminal plugsare provided for input.


3

1 2GND

PUSH

XOV

O U T P U T S I N P U T S

+–

TIP

RING

SLEEVEGND

P.I.P.–XOV is a versatile 18 dB/octave mono crossover/filterwith biamping and triamping capabilities


3

1 2GND

PUSH PUSH

FMX

C H - 2 I N P U T S C H - 1 I N P U T S

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

PA


+– +–LINE MIC

MIC LEVEL

C H - 2 I N P U T S

CH-2 CH-1

REMOTE

+– +–MIC LINE

MIC LEVEL

C H - 1 I N P U T S

P.I.P.–PA adds a switchable balanced low-impedance micinput, a balanced line-level input and a compressor to eachchannel. Remote switching circuitry provides quick and quietfades from mic to line and back.

+– +–OUT

C H - 2

+– +–IN OUT

C H - 1

BEQ


IN

P.I.P.–BEQ is a two-channel module providing equalizationfor BOSE® loudspeakers. For example, the P.I.P.–BEQ canbe used in place of a BOSE 102 controller. Screw terminalplugs provide balanced connections. Each input channelhas an output from the P.I.P. that can be independently con-figured for output with no processing, loudspeaker equaliza-tion or loudspeaker equalization with bass-cut.

RPA

ProgrammableInput Processor + – + –

MIC

LINE

PHAN

TIE

RMT B

RMT A

OUT

INOUT

INRMT C

RMT D

+10 V

A U D I O B U S

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 LEVEL

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 priorityswitching (“voice-over”) of each input and remote level con-trol with the RPA–RMT. Other features include bus inputs andoutputs, adjustable input sensitivity, phantom power and RFIsuppression. Input isolation transformers are optional.

For more information on these or other P.I.P.s underdevelopment, contact your local dealer or Crown’sTechnical Support Group.


8.2 Cooling Fan OptionsEvery Macro-Tech amplifier has a built-in high-velocityfan that provides optimum cooling. Two optional re-placement fan blades are available for special coolingrequirements. Crown part C 6594-3 is a quieter, low-velocity fan blade that in many cases can provide ad-equate cooling. Crown part C 6593-5 is a reverse airflow fan blade which changes the direction of the airflow in and out of the amplifier (not recomended for theMacro-Tech 2400). Important: The optional replace-ment fan blades should only be installed by a qualifiedtechnician.

8.3 Level Control Security KitThe MA-LOCK security accessory can be used to se-cure your amplifier’s level controls in situations wherethe front panel controls are subject to tampering. TheMA-LOCK security kit includes the necessary hard-ware to lock the two level controls on the front panel ofany Macro-Tech amplifier. For more information, con-tact your local Crown dealer or Crown’s Technical Sup-port Group.

Fig. 8.2 Installing an MA-LOCKLevel Control Shaft Lock


9 ServiceThis unit has very sophisticated circuitry which shouldonly be serviced by a fully trained technician. This isone reason why each unit bears the following label:

CAUTION: To prevent electric shock, do not removecovers. No user serviceable parts inside. Refer ser-vicing to a qualified technician.

9.1 Worldwide ServiceService may be obtained from an authorized servicecenter. (Contact your local Crown/Amcron representa-tive or our office for a list of authorized service cen-ters.) To obtain service, simply present the bill of saleas proof of purchase along with the defective unit to anauthorized service center. They will handle the neces-sary paperwork and repair.

Remember to transport your unit in the original factorypack.

9.2 North American ServiceService may be obtained in one of two ways: from anauthorized service center or from the factory. You maychoose either. It is important that you have your copyof the bill of sale as your proof of purchase.

9.2.1 Service at a North American Service CenterThis method usually saves the most time and effort.Simply present your bill of sale along with the defectiveunit to an authorized service center to obtain service.They will handle the necessary paperwork and repair.Remember to transport the unit in the original factorypack. A list of authorized service centers in your areacan be obtained from our Technical Support Group.

9.2.2 Factory ServiceTo obtain factory service, fill out the service informa-tion page that follows and send it along with your proofof purchase and the defective unit to the Crown fac-tory. For warranty service, we will pay for ground ship-ping both ways in the United States after receivingcopies of the shipping receipts. Shipments should besent “UPS ground.” (If the unit is under warranty, youmay send it C.O.D. for the cost of freight via UPSground.) The factory will return it via UPS ground.Please contact us if other arrangements are required.

your unit’s shipping pack. Do not send the ser-vice information form separately.

2. To ensure the safe transportation of your unit tothe factory, ship it in an original factory packingcontainer. If you don’t have one, call or writeCrown’s Parts Department. With the exceptionof polyurethane or wooden crates, any otherpacking material will not be sufficient to with-stand the stress of shipping. Do not use loose,small size packing materials.

3. Do not ship the unit in any kind of cabinet (woodor metal). Ignoring this warning may result in ex-tensive damage to the unit and the cabinet. Ac-cessories are not needed—do not send theinstruction manual, cables and other hardware.

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

Always use theoriginal factory packto transport the unit.

Factory Service Shipping Instructions:

1. When sending a Crown product to the factoryfor service, be sure to fill out the service infor-mation form that follows and enclose it inside

Crown Audio DivisionTechnical Support / Factory ServicePlant 2 SW, 1718 W. Mishawaka Rd., Elkhart,Indiana 46517 U.S.A.

Telephone: 219-294-8200800-342-6939 (North America, Puerto Rico, and Virgin Islands only)

Facsimile: 219-294-8301 (Technical Support)219-294-8124 (Factory Service)

Fax Back: 219-293-9200 (North America only)800-294-4094 (North America only)219-294-8100 (International)

Internet: http://www.crownintl.com

Det

ach

and

sen

d w

ith u

nit.

Crown Factory Service InformationShipping Address: Crown International, Inc., Factory Service, Plant 2 SW, 1718 W. Mishawaka Rd., Elkhart, IN 46517

Phone: 1-800-342-6939 or 1-219-294-8200 Fax: 1-219-294-8124

Owner’s Name: _________________________________________________________________________

Shipping Address: ______________________________________________________________________

Phone Number: _____________________________ Fax 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.)

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

Other equipment in your system: _________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

If warranty has expired, payment will be: Cash/Check VISA MasterCard C.O.D.

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

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

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