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

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

Some models may be exported under the name Amcron®.

130252-1A3/03

©2003 by Crown Audiol, Inc., P.O. Box 1000, Elkhart, IN 46515-1000 U.S.A. Telephone: 574-294-8000.Fax: 574-294-8329. Trademark Notice: SmartAmp, PIP and Grounded Bridge are trademarks andAmcron, Crown, Macro-Tech, IOC, ODEP, IQ System, and P.I.P. are registered trademarks of CrownInternational, Inc. Other trademarks are the property of their respective owners.

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 for failure,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 (except asexcluded), 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, thenyou must make the defective or malfunctioning product available to us freeand clear of all liens or other encumbrances. The refund will be equal tothe actual purchase price, not including interest, insurance, closing costs,and other finance charges less a reasonable depreciation on the productfrom the date of original purchase. Warranty work can only be performedat our authorized service centers. We will remedy the defect and ship theproduct from the service center within a reasonable time after receipt of thedefective product at our authorized service 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 time whichyou are deprived of the use of the new Crown product. Repairs andreplacement parts provided under the terms of this Crown Warranty shallcarry only the unexpired portion 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 PURCHASERNo 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.

9/90

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, or losswhich is covered under any of your insurance contracts. This Crown Warrantyalso does not extend to the new Crown product if the serial number has beendefaced, 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 at thefactory. We will remedy the defect and ship the product from the service centeror our factory within a reasonable time after receipt of the defective product atour authorized service center or our factory. All expenses in remedying thedefect, including surface shipping costs in the United States, will be borne by us.(You must bear the expense of shipping the product between any foreigncountry and the port of entry in the United States and all taxes, duties, and othercustoms 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 shipped ina factory pack, which, if needed, may be obtained from us free of charge.Corrective action will be taken within a reasonable time of the date of receipt ofthe defective product by us or our authorized service center. If the repairs madeby us or our authorized service center are not satisfactory, notify us or ourauthorized 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 DO NOTALLOW 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 than ninety(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 of theequipment. Nor does it cover every possible situation which may arise during installation, operation or mainte-nance. If your unit bears the name “Amcron,” please substitute it for the name “Crown” in this manual. If you needspecial assistance beyond the scope of this manual, please contact our Technical Support Group.

Crown Technical Support Group1718 W. Mishawaka Rd., Elkhart, Indiana 46517 U.S.A.

Phone: 800-342-6939 (North America, Puerto Rico and Virgin Islands) or 574-294-8200Fax: 574-294-8301 Fax Back (North America only): 800-294-4094 or 574-293-9200

Fax Back (International): 574-294-8100 Internet: http://www.crownaudio.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 operatingor maintenance instructions.

WARNINGTO REDUCE THE RISK OF ELECTRIC

SHOCK, DO NOT EXPOSE THISEQUIPMENT TO RAIN OR MOISTURE!

Magnetic FieldCAUTION! Do not locate sensitive high-gainequipment such as preamplifiers or tape decksdirectly above or below the unit. Because thisamplifier has a high power density, it has a strongmagnetic field which can induce hum into unshieldeddevices that are located nearby. The field is strongestjust above and 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

Reference Manual

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

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

2 Controls, Indicators & Connectors ................................... 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..................................................................... 388.1 PIP Modules .............................................................. 388.2 Cooling Fan Options .................................................. 408.3 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


Reference Manual

ILLUSTRATIONS1.1 Macro-Tech Amplifier ................................................................ 72.1 Front Panel Controls & Indicators .............................................. 82.2 Rear Panel Controls & Connectors ............................................ 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 Infrasonic 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 PIP Module ............................................................ 388.2 Installing a Level Control Shaft Lock ........................................ 40


Reference Manual

Important Safety Instructions

1) Read these instructions.

2) Keep these instructions.

3) Heed all warnings.

4) Follow all instructions.

5) Do not use this apparatus near water.

6) Clean only with a damp cloth.

7) Do not block any of the ventilation openings. Install in accordance with the manufacturer’s instructions.

8) Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus that pro-duce heat.

9) Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two bladeswith one wider than the other. A grounding-type plug has two blades and a third grounding prong. The wideblade or the third prong is provided for your safety. When the provided plug does not fit into your outlet,consult an electrician for replacement of the obsolete outlet.

10) Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles,and the point where they exit from the apparatus.

11) Only use attachments/accessories specified by the manufacturer.

12) Use only with a cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the appara-tus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.

13) Unplug this apparatus during lightning storms or when unused for long periods of time.

14) Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been dam-aged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects havefallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, orhas been dropped.


Reference Manual

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 PIP expandability,Macro-Tech amplifiers can be easily customized withone of our many optional input modules (see Section 8for a list of available PIP™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 claim forshipping damage. Crown will be happy to cooperatefully as needed. Save the shipping carton as evidenceof 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 results arelower 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.

PIP (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 low-frequency 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 connect out-put wiring.

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

Efficient heat sinks and a self-contained forced-air coolingsystem dissipate heat quickly and evenly for extra ampli-fier protection and greater power output.

Extra rugged, extruded aluminum front panel with ODEPand signal presence/IOC indicators for each channel, andan 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.

Fig. 1.1 Macro-Tech Amplifier


Reference Manual

Fig. 2.1 Front Panel Controls & Indicators

2 Controls, Indicators &ConnectorsA. 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 Device

Emulation 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 and off.When turned on, the output is muted for approximatelyfour seconds to protect your system from start-up tran-sients. (This delay can be changed. Contact Crown’sTechnical 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. SeeSection 7 for AC power usage.

H. Stereo/Mono SwitchThe three operating modes of a Macro-Tech amplifier


Reference Manual

Fig. 2.2 Rear Panel Controls & Connectors (Note: Reset Switches (Item I) only available on the Macro-Tech 2400 model.)

are controlled by this switch. Stereo mode is used fornormal two-channel operation, Bridge-Mono mode isused 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. PIP ModuleThe standard P.I.P.- FX is included with your amplifier. Itprovides female three-pin XLR input connectors. A va-riety of other PIP 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 PIP modules).

Input Sensitivity Switch (not shown)The three-position input sensitivity switch located insidethe amplifier can be set after removing the PIP module(J). It is set at the factory to 0.775 volts for standard 1-kHz output into 8 ohms. It can also be set to 1.4 volts forstandard 1-kHz output into 8 ohms, or a fixed voltagegain 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 PIP in-put connectors, input signals should not be connectedto the phone jacks when certain PIP modules are in-stalled (see Section 3.3.4). The phone jacks can alsobe used as “daisy chain” outputs to simplify connect-ing input signals to multiple amplifiers. Caution: TheChannel 2 input should NOT be used in eitherBridge Mono or Parallel Mono 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 Bridge Mono or Paral-lel 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.


Reference Manual

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” mountingwithout a cabinet. For more efficient cooling and extrasupport in a rack, it is recommended that units bestacked 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 preventair from recycling into the front of other amplifiers. Allowat least 35 cubic feet (1 cubic meter) per minute perunit for the Macro-Tech 600 and 1200, and at least 45cubic feet (1.3 cubic meters) per minute per unit for theMacro-Tech 2400. Additional air flow may be requiredwhen driving low impedance loads at consistently highoutput levels. Refer to Section 7 for detailed informationon 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

LEVEL LEVEL

ON

OFF

30

27

24

21

1815

12

9

6

3

0 ENABLECH1 CH2

ODEP

30

27

24

219

6

3

0

SIGNAL / IOC

1815

12

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 operat-ing under worst-case conditions. If the indicators dim,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 below).At the bottom of the rack, mount the blower so it blowsoutside air into the space between the door and in frontof the amplifiers, pressurizing the “chimney” behind thedoor. This blower should not blow air into or take air outof the space behind the amplifiers. For racks without adoor, you can evacuate the rack by mounting theblower at the top of the rack so that air inside the cabi-net is drawn out the back (Option 2 below).


Reference Manual

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 use ordeliberate overpowering.

CAUTION: Always remove power from the unit andturn the level controls off while making or changingconnections. This is very important when loudspeak-ers are connected because it reduces the chance ofloud blasts that can cause loudspeaker damage.

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.

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.


Reference Manual

3.3.2 Bridge-Mono OperationBridge-Mono mode is intended for driving loads with atotal impedance of 4 ohms or more (If the load is lessthan 4 ohms, see Section 3.3.3). 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 the am-plifier off and slide the stereo/mono switch to the right(as you face the back of the amplifier). Both outputsreceive the signal from Channel 1 with the output ofChannel 2 inverted so it can be bridged with the Chan-nel 1 output. DO NOT USE THE CHANNEL 2 INPUT orthe signal level and quality may be greatly degraded.Keep the Channel 2 level control turned down com-pletely (counterclockwise).

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

Fig. 3.5 Bridge-Mono Wiring

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 as shownin Figure 3.5. THE TWO BLACK BINDING POSTS ARENOT USED AND SHOULD NOT BE SHORTED. Theload must be balanced (neither side shorted toground).

CAUTION: Be certain all equipment (meters,switches, etc.) connected to the mono output is bal-anced. To prevent oscillations, both sides of the linemust be isolated from the input grounds.


Reference Manual

Fig. 3.6 Parallel-Mono Wiring

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 you facethe back panel). Connect the input signal to Channel 1only. The Channel 2 input and level control are by-

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

Note: It is normal for the IOC indicator of Channel 2 toremain lit 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.


Reference Manual

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 output ofmost devices. Female three-pin XLR input connectorsare provided on the standard P.I.P.- FX input module(other PIP modules are described in Section 8.1). Cor-rect input wiring will depend on two factors: (1) whetherthe input 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 recommended con-nection techniques for each type of signal source.

The amplifier’s built-in ¼-inch phone jack input connec-tors can be wired similarly for balanced or unbalanced,floating or ground-referenced sources. They have a

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

Fig. 3.8 Balanced Input Wiring

standard tip-ring-sleeve (TRS) configuration: the tip ispositive (+), the ring is negative (–) and the sleeve isground (see Figure 3.9). Wiring for various sources fol-lows the XLR wiring guidelines shown in Figures 3.7and 3.8.

The phone jacks should not be used as inputs when aPIP module with active circuitry is installed. The phonejacks are in parallel with the output of the PIP module,so an input signal connected to the phone jacks canfeed backwards into the active circuitry of the PIP andcause undesirable distortion. You can use the phonejacks for signal input with any of the following PIP mod-ules installed: P.I.P.-FX, P.I.P.-BB, P.I.P.-FMX, P.I.P.- FXQand P.I.P.-FPX. All other PIP modules have active cir-cuitry and should not be installed if you plan to connectinput signals to the phone jacks. The phone jacks canalways be used as “daisy chain” outputs to feed post-processed signals from the PIP to the inputs of otheramplifiers.

Please follow the instruction in Section 3.3.2 and 3.3.3 ifthe amplifier will be used in either Bridge-Mono or Par-allel-Mono mode. Remember, do not use the Channel 2input in either of these mono modes.


Reference Manual

SOLVING INPUT PROBLEMSSometimes large infrasonic (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 wires orAC cords. This greatly lessens the chance ofhum 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

Frequency

Fig. 3.10 Infrasonic 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 RF lev-els can also cause your amplifier to prematurely acti-vate its protection circuitry, resulting in inefficientoperation. RF can be introduced into the signal by localradio 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

Frequency

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 appropriate 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 unbal-anced filters above. Filter D also incorporates the infra-sonic filter described previously.

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

A third problem to avoid is hum. The two most commonsources of hum in an audio system are inductive cou-pling 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


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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 all sys-tem devices are plugged into the same power strip. Inaddition, make sure that all cable shields are groundedat one end only.

Input and output grounds are sometimes tied togetherfor testing or metering. This can cause feedback oscil-lation from load current in the test loop. In some sys-tems, even the AC power line may provide thisfeedback path. Proper grounding, input isolation andisolation of common AC devices in the system is goodpractice.

3.3.5 Output ConnectionConsider the power-handling capacity of your load be-fore connecting it to the amplifier. Crown is not liable fordamage incurred at any time due to overpowering. Fus-ing loudspeaker lines is highly recommended (see Sec-tion 3.3.6). Also, please pay close attention to theprecautions provided in Section 4.1.

resistance increases. This is very important becausethe amplifier’s excellent damping factor can easily benegated 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 acciden-tally tie two channels together when making orbreaking connections (for example, a stan-dard 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 resis-tance introduced by inadequate loudspeaker cableswill reduce both the output power and the motion con-trol of the loudspeakers. The latter problem occurs be-cause the damping factor decreases as the cable

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


Reference Manual

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 desirablefor live sound, but long cable lengths often limit the highestdamping factor that can be achieved practically. (Underthese circumstances, Crown’s IQ System® is often used soamplifiers can be monitored and controlled when they arelocated very near the loudspeakers.) In recording studiosand home hi-fi, a damping factor of 500 or more is very desir-able.

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 the cablerun.

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

SOLVING OUTPUT PROBLEMSSometimes high-frequency oscillations occur whichcan cause your amplifier to prematurely activate its pro-tection circuitry and result in inefficient operation. Theeffects of this problem are similar to the effects of theRF problem described in Section 3.3.4. To prevent high-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 commoncable 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 low fre-quencies. This can cause the amplifier to produce largelow-frequency currents and activate its protection cir-cuitry. Always take the precaution of installing a high-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 infrasonic 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’s out-put 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


Reference Manual

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. Loud-speakers are subject to thermal damage from sus-tained 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 thermal pro-tection 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

There are basically two approaches that can be takenwhen installing fuses for loudspeaker protection. A com-mon approach is to put a single fuse in series with theoutput of each channel. This makes installation conve-nient 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-blowfuses and high-frequency drivers are protected by 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 testingconditions. Performance variations can occur at otherAC voltages and frequencies. In addition, line regula-tion problems directly affect the output power from theamplifier.


Reference Manual

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 firstturned off.

3. CAUTION: In Parallel-Mono mode, a jumper isused between the red (+) Channel 1 and 2 outputbinding posts. Be sure to remove this jumper forStereo or Bridge-Mono mode, otherwise highdistortion and excessive heating will definitelyoccur. Check the stereo/mono switch on the backpanel for proper position.

4. Turn off the amplifier and unplug it from the ACmains before removing the PIP 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 selected linevoltage 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 cooling sys-tem are working. It does not indicate the status of thehigh-voltage power supplies. For example, the Enableindicator will remain lit during unusual conditions thatwould cause the amplifier’s protection systems to put a

Fig. 4.1 Indicators

high-voltage power supply in “standby” mode (seeSection 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 the am-plifier can continue safe operation even whenconditions are severe. (For a more detailed descriptionof ODEP, see Section 4.3.1.)

The ODEP indicator for the affected channel will turn offif 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 protection circuitry(see Section 4.3.2). Both ODEP indicators turn off if theamplifier loses AC power, the power switch is turned offor 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 any dif-ference between the input and output signal waveformsgreater than 0.05%. Because transient distortion hap-pens quickly, a 0.1 second “hold delay” keeps the indi-cators on long enough to be easily noticed. The IOCfunction essentially provides proof of distortion-free per-formance. As input overload indicators, they flashbrightly with a 0.5 second hold delay to show that aninput signal is too large and must be clipped at the in-put. Note: The Channel 2 IOC indicator will remain litwhen running in Parallel-Mono mode.

Under abnormal conditions where one of the amplifier’shigh-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.


Reference Manual

The table in Figure 4.2 shows the possible states for theODEP and Signal/IOC indicators. It also describes theconditions that may be associated with the different in-dicator states. The Enable indicator will be off with thefirst indicator state, “There is no power to the amplifier.”All other conditions in the table will occur with the En-

able indicator turned on. It is important to note the pos-sible states of the indicators in the rare event that youexperience a problem. This can greatly aid in deter-mining the source of problems. Please contact your lo-cal Crown representative or our Technical SupportGroup for futher assistance.

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


Reference Manual

the 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, im-proper 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 afterthe transformer cools to a safe temperature. (For moreinformation on transformer thermal protection, refer tothe following section.)

4.3.3 Transformer Thermal ProtectionAll Macro-Tech amplifiers have transformer thermal pro-tection. It protects the power supplies from damage un-der the rare conditions of transformer temperaturesrising too high. A thermal switch embedded in eachtransformer removes power to the channel if there isexcessive heat. The switch automatically resets whenthe 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 conditions canoverheat the transformer and activate its protection sys-tem.

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 protection anddiagnostics capabilities. Protection systems includeODEP, “standby” mode, fuses (or breakers), and spe-cial 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 Emula-tion 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 falls withinthe SOA. Limiting is proportional and kept to an abso-lute minimum—only what is required to prevent outputtransistor 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 whether theamplifier is functioning correctly or if ODEP is limitingthe drive level. Second, ODEP data is fed to the backpanel PIP connector so advanced PIP modules like theIQ-PIP can use it to monitor and control the amplifier.

With ODEP, the show keeps going because you get themaximum 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 circuitryand put the affected channels in standby. This protects


Reference Manual

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 outputlevels result in current draw that exceeds their rating.Again, this should only be possible when operatingoutside rated conditions, such as when the amplifier isused to drive a 1-ohm load in Stereo mode, or when asignal overloads the input and is clipped severely.

All 120 VAC, 60 Hz units and all Macro-Tech 2400s havea separate fuse for the low-voltage power supply andcooling fan. All units have separate fuses or breakersfor 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 switchedeither to 1.4 volts for standard 1-kHz power output, orto a fixed voltage gain of 26 dB. When set to 26 dBgain, the input sensitivity is 2.2 volts for the Macro-Tech600, 2.6 volts for the Macro-Tech 1200 and 3.1 volts forthe 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 PIP 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 for

Fig. 4.3 Input Sensitivity and Ground Lift Switches

*Factory setting for international versions is 1.4 V.


Reference Manual

standard 1-kHz power, the middle position provides26 dB gain, and the back position sets thesensitivity to 0.775 volts for standard 1-kHz power.

5. Replace the PIP 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 PIP mod-ule input connectors. Sliding the switch to the left iso-lates 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 PIPmodule 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 PIP 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 breaker trips,the IOC indicator for the affected channel will turn on(see Figure 4.2).

4.5 Filter CleaningDust filters are provided on the air intakes to the coolingsystem (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.


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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 watts-per-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 area tovolume, 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-volt-age transformer TF-1. The secondary output of T100 isfull-wave rectified by D109 and is filtered by a largecomputer-grade capacitor. D104 through D107 provideboosted voltage to power LVAs and predrivers. A ther-mal switch embedded in each transformer protects itfrom overheating.

The low-voltage transformer TF-1 uses a separate wind-ing on the fan motor. The TF-1 output is rectified by di-odes D1, D2, D3 and D4 to generate an unregulated 24volts. Monolithic regulators U1 and U2 provide a regu-lated ±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 PIP module is used, the input signal first passesthrough the PIP’s circuitry and then to the balanced gainstage.

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 embodiment andthe Programmable Input Processor (PIP) expansionsystem.

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-de-structing.

Real-time computer simulation is used to create an ana-logue of the junction temperature of the output transis-tors (hereafter referred to as “output devices”). Currentis limited only when the device temperature becomesexcessive (and by the minimum amount required). Thispatented approach is called Output Device EmulationProtection (or ODEP). It maximizes the available outputpower and protects against overheating—the majorcause of device failure.

The amplifier is protected from all common hazards thatplague high-power amplifiers including shorted, openor mismatched loads; overloaded power supplies, ex-cessive temperature, chain-destruction phenomena,input overload and high-frequency blowups. The unitprotects loudspeakers from input and output DC, aswell 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 power sup-plies providing peak-to-peak voltages to the load thatare twice the voltage seen by the output devices (seeFigure 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.


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Fig. 5.1 Circuit Block Diagram


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The balanced gain stage (U104-C and U104-D) causesbalanced to single-ended conversion using a differ-ence amplifier. From there, gain can be controlled witha potentiometer. The error amp (U104-A) amplifies thedifference between the output signal and the input sig-nal from the gain pot, and drives the voltage translatorstage.

From the error amp U104-A, the voltage translator stagechannels the signal to the Last Voltage Amplifiers (LVAs)depending on the signal polarity. The +LVA (Q104 andQ105) and the –LVA (Q110 and Q111), with their push-pull effect through the bias servo Q318, drive the fullycomplementary 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 signalthen gains current amplification through the Darlingtonemitter-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 limitersremove the drive from the LVAs, thus limiting current inthe output stage to a safe level.

To further protect the output stages, the patented ODEPcircuitry is used. It produces an analog output propor-tional to the always-changing safe operating area ofthe output transistor. This output controls the translatorstage previously mentioned, removing any further drivethat may exceed the safe operating area of the outputstage.

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 to Bridge-Mono, the user can convert the Macro-Tech into abridged, single-channel amplifier. With a signal appliedto the Channel 1 input jack and the load connectedacross the red (+) back panel 5-way binding posts,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 mode ofoperation.

The signal path for Channel 1 is the same as previouslydiscussed, except Channel 1 also drives the outputstage of Channel 2. The Channel 2 balanced input, er-ror amp, translators and LVAs are disconnected and nolonger control the Channel 2 output stage. Disconnect-ing 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 mechanisms arealso 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.


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

Standard 1 kHz Power: refers to maximum average power inwatts at 1 kHz with 0.1% THD.

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

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

International Units: refers to amplifiers with special multi-taptransformers that are configurable for several AC mains voltagesand line frequencies (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: 20 Hz to 20 kHz: Better than100 dB below full bandwidth power. A-weighted: Betterthan 105 dB below full bandwidth power.

Total Harmonic Distortion (THD): Less than 0.05% atfull bandwidth power from 20 Hz to 1 kHz increasing lin-early to 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 2 to16 ohms in Stereo, 4 to 16 ohms in Bridge-Mono and 1 to 4ohms in Parallel-Mono mode.

Required AC Mains: 50/60 Hz; 100, 120, 220, 230 and 240VAC (±10%) units are available. All draw 100 watts or less atidle. Current, voltage and frequency requirements are pro-vided 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 amplifieron and off.

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


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

Sensitivity: A three-position switch inside the PIP compart-ment used to select the input sensitivity for both channels:0.775 volts or 1.4 volts for standard 1 kHz power, or a 26 dBvoltage gain.

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

Reset (Macro-Tech 2400 only): A back panel push buttonfor each channel used to reset the circuit breaker that pro-tects 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 indicatorthat flashes to show amplifier output. If a channel’s outputwaveform differs from its input by 0.05% or more, the indica-tor flashes brightly to show distortion. This function providesproof 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 indicator thatshows thermal-dynamic energy reserve. Normally, eachODEP indicator is lit to show available reserve energy. In therare event that a channel has no reserve, its indicator will dimin proportion to ODEP limiting. An ODEP indicator may alsoturn off under other conditions (see Section 4.2).

Input/OutputInput Connector: Two balanced 1/4-inch phone jacks on theback panel and two balanced three-pin female XLR connec-tors on the factory-installed P.I.P.- FX (see Section 8 for infor-mation on optional PIP modules).

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

Input Sensitivity: Settings include 0.775 volts or 1.4 volts forstandard 1 kHz power, or a 26 dB voltage gain (see Section4.4 for more information).

Output Connectors: Two sets of color-coded 5-way bindingposts (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 controlsare 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,open or mismatched loads; overloaded power supplies;excessive temperature, chain destruction phenomena,input overload damage and high-frequency blowups.They also protect loudspeakers from input/output DC andturn-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;when it has cooled to a safe temperature, the transformerwill automatically reset itself. Controlled slew-rate voltageamplifiers prevent RF burnouts. And input overload pro-tection is provided by current-limiting resistance at the in-put. Refer to Section 4.3.

Turn On: Four-second delay with no dangerous tran-sients. Contact Crown’s Technical Support Group tochange the turn-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 (6.3-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.


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

Minimum Guaranteed Power 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 in thereal world—without a clipped output signal.

Many manufacturers publish power specs with a tolerance of ±1 dB or worse. This means their amplifier can deviate more than20% in output! A 100-watt amplifier would meet their specification if it only produced 79.4 watts. Other manufacturers qualifytheir specs by saying they are “typical,” “subject to manufacturing tolerances,” “single channel driven” or that they are specifiedwith “fuses bypassed.” Each of these statements effectively removes any performance guarantee. In fact, some manufacturersuse these tactics to generate large power numbers, and they don’t even print a disclaimer. We take a different approach atCrown—our amplifiers are guaranteed to meet or exceed their specifications for three years. Further, because our publishedspecs are set below our “in-house” measurements, you can expect every Crown amplifier to exceed its published minimumpower specs. We believe you should get what you pay for.

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 Power speci-fication.

1. A 1-kHz sine wave is presented to the ampli-fier and the output monitored for nonlinear dis-tortion. The level is increased until the THDreaches 0.1%. At this level the average powerper 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 nonlinear dis-tortion. 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 to bea minimum of five minutes of operation. Har-monic distortion is measured as the RMS sumtotal and given as a percentage of the funda-mental output voltage. This applies for all watt-ages greater than 0.25 watts.


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

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, so thesingle 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 amplifierat levels higher than 0.05% THD can result in output power levels that are higher than those listed in the maximum powermatrices.

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 specified forthe 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.


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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


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TEF ®

+45˚

0˚

–45˚

100 1 K 10 K 20 K

FREQUENCY (Hz)

100 1 K 10 K 20 K

FREQUENCY (Hz)

dB

TEF ®

TEFMeasurement

Fig. 6.11 Typical Crosstalk for the Macro-Tech 600

TEFMeasurement

–51

–57

–63

–69

–75

–81

Fig. 6.10 Typical Phase Response


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100 1 K 10 K 20 K

FREQUENCY (Hz)

dB

TEF ®

100 1 K 10 K 20 K

FREQUENCY (Hz)

dB

TEF ®


–66

–72

–78

–84

–90

–96

–102

TEFMeasurement


–60

–66

–72

–78

–84

–96

–90

TEFMeasurement


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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 with 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 follow-ing equation converts power draw in watts to currentdraw 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 calculatethermal 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. Ifyou 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

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


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8 Accessories8.1 PIP ModulesOne advantage of Macro-Tech amplifiers is the abilityto customize them using PIP (Programmable Input Pro-cessor) and PIP2 modules. Macro-Tech amplifiers areequipped with an edge card connector inside the backpanel PIP compartment. The modules install easily:

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 filters,18-dB/octave high-pass filters, and 6-dB/octave 3-kHz shelvingnetworks for “constant-directivity” horn equalization. Screw ter-minal plugs are provided for input.

IQ–P.I.P.®–MEM is PIP2-compatible and integrates the amplifierinto Crown’s patented IQ System. The IQ System provides com-puter control of 1 to 2000 amplifiers. For example, each amplifierchannel can be monitored and controlled from a personal com-puter attached to an IQ System. A memory backup feature en-ables the IQ–PIP–MEM to remember all configuration settingswhen the power is turned off.

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, power sup-ply gates for energy savings, ODEP conservation to protect out-put devices with precision input signal control, interrupt-drivenreporting that lets you define error conditions, and configurableshort circuit detection.

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 addition,the IQ–P.I.P.–DSP includes all the SmartAmp features of the IQ–P.I.P.–SMT to give you access to standard IQ System amplifierfunctions and autonomous operation.

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

PIPs 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 PIP and PIP2 modules:

P.I.P.®–AMCb unites many features of the P.I.P.-XOV and P.I.P.–CLP. It offers a variable 4th-order Linkwitz-Riley crossover and anIOC-driven, variable threshold compressor. In addition, it pro-vides “constant-directivity” horn equalization and filter-assistedB6 vented box equalization. Biamping and triamping capabilitiesare provided via three-pin XLR connectors.

P.I.P.®–EDCb combines a sophisticated error-driven compres-sor and smooth limiter with a maximum level setting and a sub-sonic filter for each channel. The compressors have adjustableattack and release times, and can be set to track each other. Thecompressors activate when a signal would otherwise clip theinput, an IOC error occurs, or the output exceeds the selectedthreshold. The subsonic filters have corner frequencies of 24,28, 32 and 36 Hz.

P.I.P.MODULE

BACK PANEL

OF AMPLIFIER

Fig. 8.1 Installing a PIP Module


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perationtion.

P.I.P.®–CLP detects and prevents overload. Its compressoris driven 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.

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.

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

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

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.

P.I.P.®–BEQ is a two-channel module providing equalizationfor BOSE® loudspeakers. For example, the P.I.P.–BEQ can beused in place of a BOSE 102 controller. Screw terminal plugsprovide balanced connections. Each input channel has anoutput from the PIP that can be independently configured foroutput with no processing, loudspeaker equalization or loud-speaker equalization with bass-cut.

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 PIPs under de-velopment, contact your local dealer or Crown’s Tech-nical Support Group.


Reference Manual

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 reverseair-flow fan blade which changes the direction of the airflow in and out of the amplifier (not recommended forthe Macro-Tech 2400). Important: The optional replace-ment fan blades should only be installed by a qualifiedtechnician.

8.3 Level Control Shaft LockA security accessory, the shaft lock can be used to se-cure your amplifier’s level controls in situations wherethe front panel controls are subject to tampering. Oneis needed for each channel. They can be orderedthrough the Crown Service/Parts Department. For moreinformation, contact the Crown Service Department.

Fig. 8.2 Installing a Level Control Shaft Lock


Reference Manual

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 centers.)To obtain service, simply present the bill of sale as proofof purchase along with the defective unit to an autho-rized service center. They will handle the necessarypaperwork 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 copy ofthe 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 found in the back of this manual and send italong with your proof of purchase and the defectiveunit to the Crown factory.

For warranty service, we will pay for ground shippingboth ways in the United States. Contact Crown FactoryService or Technical Support to obtain prepaid ship-ping labels prior to sending the unit. Or, if you prefer,you may prepay the cost of shipping, and Crown willreimburse you. Send copies of the shipping receipts toCrown to receive reimbursement.

1. When sending a Crown product to the factory forservice, be sure to fill out the service informationform that follows and enclose it inside your unit’sshipping pack. Do not send the service informa-tion 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 exception ofpolyurethane or wooden crates, any other pack-ing material will not be sufficient to withstand thestress of shipping. Do not use loose, small sizepacking 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 the CrownTechnical Support Group.

Always use theoriginal factory packto transport the unit.

Your repaired unit will be returned via UPS ground.Please contact us if other arrangements arerequired.Factory Service Shipping Instructions:

Crown InternationalTechnical Support / Factory Service1718 W. Mishawaka Rd., Elkhart, Indiana 46517U.S.A.

Telephone: 574-294-8200800-342-6939 (North America, Puerto Rico, and Virgin Islands only)

Facsimile: 574-294-8301 (Technical Support)574-294-8124 (Factory Service)

Fax Back: 574-293-9200 (North America only)800-294-4094 (North America only)574-294-8100 (International)

Internet: http://www.crownaudio.com

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Crown Factory Service InformationShipping Address: Crown Factory Service, 1718 W. Mishawaka Rd., Elkhart, IN 46517

Phone: 1-800-342-6939 or 1-574-294-8200 Fax: 1-574-294-8124

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.)

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Other equipment in your system:__________________________________________________________

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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.

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

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Transcript of Models: Macro-Tech 600, 1200 & 2400 Macro-Tech 601, 1201 ...