Crown MA-1200, MA-1201, MA-2400, MA-2401, MA-601 Brochure

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

Some models may be exported under the name Amcron

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

Approved for
THX Theatre
Systems

®

.

130252-1A

3/03

3

YEAR

THREE YEAR

FULL WARRANTY

3

YEAR

WORLDWIDE

The Crown Audio Division of Crown International, Inc., 1718 West
Mishawaka Road, Elkhart, Indiana 46517-4095 U.S.A. warrants to you,
the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of each
NEW Crown
purchase by the original purchaser (the “warranty period”) that the new
Crown product is free of defects in materials and workmanship, and we
further warrant the new Crown product regardless of the reason for failure,
except as excluded in this Crown Warranty.

1

Note: If your unit bears the name “Amcron,” please substitute it for the

name “Crown” in this warranty.

ITEMS EXCLUDED FROM THIS CROWN WARRANTY

This Crown Warranty is in effect only for failure of a new Crown product
which occurred within the Warranty Period. It does not cover any product
which has been damaged because of any intentional misuse, accident,
negligence, or loss which is covered under any of your insurance
contracts. This Crown Warranty also does not extend to the new Crown
product if the serial number has been defaced, altered, or removed.

We will remedy any defect, regardless of the reason for failure (except as
excluded), by repair, replacement, or refund. We may not elect refund
unless you agree, or unless we are unable to provide replacement, and
repair is not practical or cannot be timely made. If a refund is elected, then
you must make the defective or malfunctioning product available to us free
and clear of all liens or other encumbrances. The refund will be equal to
the actual purchase price, not including interest, insurance, closing costs,
and other finance charges less a reasonable depreciation on the product
from the date of original purchase. Warranty work can only be performed
at our authorized service centers. We will remedy the defect and ship the
product from the service center within a reasonable time after receipt of the

defective product at our authorized service center.

You must notify us of your need for warranty service not later than ninety
(90) days after expiration of the warranty period. All components must be
shipped in a factory pack. Corrective action will be taken within a
reasonable time of the date of receipt of the defective product by our
authorized service center. If the repairs made by our authorized service
center are not satisfactory, notify our authorized service center
immediately.

DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGES

YOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTAL
DAMAGES RESULTING FROM ANY DEFECT IN THE NEW CROWN
PRODUCT. THIS INCLUDES ANY DAMAGE TO ANOTHER PRODUCT
OR PRODUCTS RESULTING FROM SUCH A DEFECT.

No person has the authority to enlarge, amend, or modify this Crown
Warranty. This Crown Warranty is not extended by the length of time which
you are deprived of the use of the new Crown product. Repairs and
replacement parts provided under the terms of this Crown Warranty shall
carry only the unexpired portion of this Crown Warranty.

We reserve the right to change the design of any product from time to time
without notice and with no obligation to make corresponding changes in
products previously manufactured.

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

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS

CONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.

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

SUMMARY OF WARRANTY

1

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

WHAT THE WARRANTOR WILL DO

HOW TO OBTAIN WARRANTY SERVICE

WARRANTY ALTERATIONS

DESIGN CHANGES

LEGAL REMEDIES OF PURCHASER

9/90

NORTH AMERICA

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

ITEMS EXCLUDED FROM THIS CROWN WARRANTY

This Crown Warranty is in effect only for failure of a new Crown product which
occurred within the Warranty Period. It does not cover any product which has
been damaged because of any intentional misuse, accident, negligence, or loss
which is covered under any of your insurance contracts. This Crown Warranty
also does not extend to the new Crown product if the serial number has been
defaced, altered, or removed.

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

You must notify us of your need for warranty service not later than ninety (90)
days after expiration of the warranty period. All components must be shipped in
a factory pack, which, if needed, may be obtained from us free of charge.
Corrective action will be taken within a reasonable time of the date of receipt of
the defective product by us or our authorized service center. If the repairs made
by us or our authorized service center are not satisfactory, notify us or our
authorized service center immediately.

DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGES

YOU ARE NOT ENTITLED TO RECOVER FROM US ANY INCIDENTAL
DAMAGES RESULTING FROM ANY DEFECT IN THE NEW CROWN
PRODUCT. THIS INCLUDES ANY DAMAGE TO ANOTHER PRODUCT OR
PRODUCTS RESULTING FROM SUCH A DEFECT. SOME STATES DO NOT

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

No person has the authority to enlarge, amend, or modify this Crown Warranty.
This Crown Warranty is not extended by the length of time which you are
deprived of the use of the new Crown product. Repairs and replacement parts
provided under the terms of this Crown Warranty shall carry only the unexpired
portion of this Crown Warranty.

We reserve the right to change the design of any product from time to time
without notice and with no obligation to make corresponding changes in
products previously manufactured.

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

THIS STATEMENT OF WARRANTY SUPERSEDES ANY OTHERS

CONTAINED IN THIS MANUAL FOR CROWN PRODUCTS.

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

SUMMARY OF WARRANTY

WHAT THE WARRANTOR WILL DO

HOW TO OBTAIN WARRANTY SERVICE

WARRANTY ALTERATIONS

DESIGN CHANGES

LEGAL REMEDIES OF PURCHASER

9/90

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

Crown Technical Support Group

1718 W. Mishawaka Rd., Elkhart, Indiana 46517 U.S.A.

Phone: [phone] (North America, Puerto Rico and Virgin Islands) or 574-294-8200

Fax: [phone] Fax Back (North America only): 800-294-4094 or 574-293-9200

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

IMPORTANT

THE MACRO-TECH 2400 REQUIRES CLASS 1

OUTPUT WIRING. THE MACRO-TECH 600 &

1200 REQUIRE CLASS 2 OUTPUT WIRING.

C A U T I O N

RISK OF ELECTRIC SHOCK

DO NOT OPEN

TO PREVENT ELECTRIC SHOCK DO

NOT REMOVE TOP OR BOTTOM

COVERS. NO USER SERVICEABLE

PARTS INSIDE. REFER SERVICING
TO QUALIFIED SERVICE PERSON-

NEL. DISCONNECT POWER CORD

BEFORE REMOVING REAR INPUT

MODULE TO ACCESS GAIN SWITCH.

WARNING

TO REDUCE THE RISK OF ELECTRIC

SHOCK, DO NOT EXPOSE THIS

EQUIPMENT TO RAIN OR MOISTURE!

A V I S

RISQUE DE CHOC ÉLECTRIQUE

N’OUVREZ PAS

À PRÉVENIR LE CHOC ÉLECTRIQUE
N’ENLEVEZ PAS LES COUVERCLES.

IL N’Y A PAS DES PARTIES

SERVICEABLE À L’INTÉRIEUR. TOUS

REPARATIONS DOIT ETRE FAIRE PAR

PERSONNEL QUALIFIÉ SEULMENT.

DÉBRANCHER LA BORNE AVANT

D’OUVRIR LA MODULE EN ARRIÈRE.

Magnetic Field

CAUTION! Do not locate sensitive high-gain

equipment such as preamplifiers or tape decks
directly above or below the unit. Because this

amplifier has a high power density, it has a strong
magnetic field which can induce hum into unshielded
devices that are located nearby. The field is strongest
just above and below the unit.

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

The lightning bolt
triangle is used to
alert the user to the
risk of electric shock.

The exclamation point
triangle is used to alert the
user to important operating
or maintenance instructions.

Printed on

recycled paper.

Macro-Tech 600/1200/2400 Power Amplifiers

CONTENTS

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

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

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

2 Controls, Indicators & Connectors ................................... 8

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

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

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

3.3 Wiring ........................................................................ 11

3.3.1 Stereo (Two-Channel) Operation...................... 11

3.3.2 Bridge-Mono Operation ................................... 12

3.3.3 Parallel-Mono Operation .................................. 13

3.3.4 Input Connection ............................................. 14

3.3.5 Output Connection .......................................... 16

3.3.6 Additional Load Protection .............................. 18

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

4 Operation......................................................................... 19

4.1 Precautions................................................................ 19

4.2 Indicators .................................................................. 19

4.3 Protection Systems .................................................... 21

4.3.1 ODEP .............................................................. 21

4.3.2 Standby Mode................................................. 21

4.3.3 Transformer Thermal Protection ....................... 21

4.3.4 Fuses and Circuit Breakers.............................. 22

4.4 Controls ..................................................................... 22

4.5 Filter Cleaning ............................................................ 23

5 Technical Information ..................................................... 24

5.1 Overview ................................................................... 24

5.2 Circuit Theory ............................................................ 24

5.2.1 Stereo Operation ............................................. 24

5.2.2 Bridge-Mono Operation ................................... 26

5.2.3 Parallel-Mono Operation .................................. 26

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

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

8 Accessories..................................................................... 38

8.1 PIP Modules .............................................................. 38

8.2 Cooling Fan Options .................................................. 40

8.3 Level Control Security Kit ........................................... 40

9 Service............................................................................. 41

9.1 Worldwide Service ..................................................... 41

9.2 North American Service ............................................. 41

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

9.2.2 Factory Service ............................................... 41

Page 4 Reference Manual

Macro-Tech 600/1200/2400 Power Amplifiers

1.1 Macro-Tech Amplifier ................................................................ 7

2.1 Front Panel Controls & Indicators .............................................. 8

2.2 Rear Panel Controls & Connectors ............................................ 9

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

3.2 Top View of a Rack-Mounted Unit............................................ 10

3.3 Proper Air Flow in a Rack Cabinet ........................................... 10

3.4 Stereo Wiring ..........................................................................11

3.5 Bridge-Mono Wiring ................................................................ 12

3.6 Parallel-Mono Wiring ............................................................... 13

3.7 Unbalanced Input Wiring ........................................................ 14

3.8 Balanced Input Wiring ............................................................. 14

3.9 Balanced and Unbalanced Phone Plugs ................................. 14

3.10 Infrasonic Filter Capacitors ...................................................... 15

3.11 Unbalanced RFI Filters ............................................................ 15

3.12 Balanced RFI Filters ................................................................15

3.13 Wire Size Nomograph .............................................................16

3.14 Inductive Load (Transformer) Network ..................................... 17

3.15 Loudspeaker Fuse Nomograph .............................................. 18

4.1 Indicators................................................................................ 19

4.2 Macro-Tech ODEP and Signal/IOC Indicator States ................. 20

4.3 Input Sensitivity and Ground Lift Switches ............................... 22

5.1 Circuit Block Diagram ............................................................. 25

6.1 Macro-Tech 600 Minimum Power Matrix .................................. 29

6.2 Macro-Tech 1200 Minimum Power Matrix ................................ 30

6.3 Macro-Tech 2400 Minimum Power Matrix ................................ 30

6.4 Macro-Tech 600 Maximum Power Matrix ................................. 31

6.5 Macro-Tech 1200 Maximum Power Matrix ............................... 32

6.6 Macro-Tech 2400 Maximum Power Matrix ............................... 32

6.7 Typical Frequency Response ..................................................33

6.8 Typical Damping Factor .......................................................... 33

6.9 Typical Output Impedance ...................................................... 33

6.10 Typical Phase Response .........................................................34

6.11 Typical Crosstalk for the Macro-Tech 600 ................................ 34

6.12 Typical Crosstalk for the Macro-Tech 1200 .............................. 35

6.13 Typical Crosstalk for the Macro-Tech 2400 .............................. 35

7.1 Macro-Tech 600 Power Draw, Current Draw and

Thermal Dissipation at Various Duty Cycles ............................. 36

7.2 Macro-Tech 1200 Power Draw, Current Draw and

Thermal Dissipation at Various Duty Cycles ............................. 37

7.3 Macro-Tech 2400 Power Draw, Current Draw and

Thermal Dissipation at Various Duty Cycles ............................. 37

8.1 Installing a PIP Module ............................................................ 38

8.2 Installing a Level Control Shaft Lock ........................................ 40

ILLUSTRATIONS

Reference Manual

Page 5

Macro-Tech 600/1200/2400 Power Amplifiers

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 pro­duce heat.

9) Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades
with one wider than the other. A grounding-type plug has two blades and a third grounding prong. The wide
blade or the third prong is provided for your safety. 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 appara­tus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip­over.

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 dam­aged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have
fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or
has been dropped.

Page 6 Reference Manual

Macro-Tech 600/1200/2400 Power Amplifiers

Fig. 1.1 Macro-Tech Amplifier

1 Welcome

Congratulations on your purchase of the renowned

Macro-Tech

amplifiers are designed to provide enormous levels of
pure, undistorted power in a rugged low-profile pack­age—making them
ment. They utilize our patented ODEP® protection
circuitry to
fiers have shut down. And with their PIP expandability,
Macro-Tech amplifiers can be easily customized with
one of our many optional input modules (see Section 8
for a list of available PIP

This manual will help you successfully install and use
your new amplifier. Please read all instructions, warn­ings and cautions. Be sure to read Sections 3.3.2 and

3.3.3 if you plan to use one of the amplifier’s two mono
modes. Also for your protection, please send in your
warranty registration card today and save your bill of
sale because it is your official proof of purchase.

1.1 Unpacking

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

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

WITHOUT THE FACTORY PACK.

1.2 Features

Macro-Tech amplifiers use cutting edge technology to
deliver the ultimate in power and value for their size,
weight and price. They offer numerous advantages
over conventional designs and provide benefits you
can’t get in amplifiers from any other manufacturer.

Reference Manual

®

professional power amplifier. Macro-Tech

the choice

keep the show going

for pro sound reinforce-

long after other ampli-

™

s

).

Here are some of their many features:

 Crown’s Grounded Bridge™ design delivers large voltage

swings without using easily stressed output- transistor
configurations like conventional amplifiers. The results are
lower distortion and superior reliability.

 Patented ODEP (Output Device Emulation Protection) cir-

cuitry compensates for overheating and overload to keep
the amplifier working when others would fail.

®

 IOC

 PIP (Programmable Input Processor) connector accepts

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

 Very low harmonic and intermodulation distortion result in

 High damping factor provides superior control over low-

 Full protection against shorted outputs, mismatched

 Dedicated power supply transformers isolate channels in

 Balanced inputs with internal three-position sensitivity

 Versatile 5-way binding posts make it easy to connect out-

 Ground lift switch isolates the AC power and phone jack

 Efficient heat sinks and a self-contained forced-air cooling

 Extra rugged, extruded aluminum front panel with ODEP

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

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

(Input/Output Comparator) circuitry immediately
alerts of any distortion exceeding 0.05%, providing dy­namic

proof of distortion-free performance

accessories that tailor the amplifier to suit specific appli­cations.

driving a wide range of load impedances.

the best

frequency drivers for a clean, accurate low end.

loads, input/output DC, general overheating, high-fre­quency overloads and internal faults.

Stereo mode for superb crosstalk characteristics and reli­ability—each channel is virtually a separate amplifier.

switch and adjustable front-panel level controls.

put wiring.

audio grounds.

system dissipate heat quickly and evenly for extra ampli­fier protection and greater power output.

and signal presence/IOC indicators for each channel, and
an Enable indicator.

(units can also be stacked).

your investment and guarantees its specifications.

dynamic transfer function

in the industry.

.

Page 7

Fig. 2.1 Front Panel Controls & Indicators

2 Controls, Indicators &
Connectors

A. Dust Filters

The dust filters remove large particles from the air
drawn in by the cooling fan. Check the filters regularly
to prevent clogging. The filter elements can be easily
removed for cleaning by gently pulling them away from
the front panel (see Sections 3.2 and 4.5).

B. Level Controls

The output level for each channel is set with these con­venient level controls mounted on the front panel. Each
level control has 31 detents for precise adjustment (see
Section 4.4). A security option is available to prevent
tampering (see Section 8.3).

Macro-Tech 600/1200/2400 Power Amplifiers

Emulation Protection) circuitry, these amber indicators
glow brightly to show the presence of reserve thermal­dynamic energy. They dim proportionally as energy re­serves decrease. In the rare event that energy reserves
are depleted, the indicators turn off and ODEP propor­tionally limits output drive so the amplifier can safely
continue operating even under severe conditions.
These indicators can also help identify more unusual
operating conditions (see Section 4.2).

E. Enable Indicator

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

C. Signal/IOC Indicators

These green multifunction indicators show signal pres­ence and distortion for each channel. As signal pres­ence indicators, they flash synchronously with the
output audio signals to show their presence. As IOC
(Input/Output Comparator) indicators, they flash
brightly with a 0.1 second hold delay if there is a differ­ence of 0.05% or more between the input and output
signal waveforms. This provides

performance

overload. If an input signal is too large, the indicator for
the affected channel flashes brightly with a 0.5 second
hold delay to show clipping distortion.

nel 2 IOC indicator stays on in Parallel-Mono mode (see
Section 4.2).

. Another IOC function is to indicate input

proof of distortion-free

Note: The Chan-

D. ODEP Indicators

During normal operation of the ODEP (Output Device

Page 8 Reference Manual

F. Enable Switch

This push button is used to turn the amplifier on and off.
When turned on, the output is muted for approximately
four seconds to protect your system from start-up tran­sients. (This delay can be changed. Contact Crown’s
Technical Support Group for details.)

G. Power Cord

The power cord has an appropriate plug for the re­quired voltage. 120 VAC, 60 Hz North American Macro­Tech 600s and 1200s have 14 AWG line cords and
NEMA 5-15P plugs. Macro-Tech 2400s have 12 AWG
line cords and NEMA 5-20P plugs. International units
are shipped with an appropriate line cord and plug. See
Section 7 for AC power usage.

H. Stereo/Mono Switch

The three operating modes of a Macro-Tech amplifier

Macro-Tech 600/1200/2400 Power Amplifiers

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 for
normal two-channel operation, Bridge-Mono mode is
used to drive a single channel with a load impedance
of at least 4 ohms, and Parallel-Mono mode is used to
drive a single channel with an impedance less than 4
ohms.

Important: Turn off the amplifier before

changing the stereo/mono switch (see Section 3.3).

I. Reset Switches (Macro-Tech 2400 only)

The Macro-Tech 2400 has a back panel Reset switch
for each channel. Each switch resets the circuit breaker
that protects the channel’s power supply from overload.

J. PIP Module

The standard P.I.P.- FX is included with your amplifier. It
provides female three-pin XLR input connectors. A va­riety of other PIP modules can be used in place of the
P.I.P.-FX. They add additional features that customize
the amplifier for different applications (see Section 8.1
for information on available PIP modules).

 Input Sensitivity Switch (not shown)

The three-position input sensitivity switch located inside
the amplifier can be set after removing the PIP module
(J). It is set at the factory to 0.775 volts for standard 1­kHz output into 8 ohms. It can also be set to 1.4 volts for
standard 1-kHz output into 8 ohms, or a fixed voltage
gain of 26 dB (see Section 4.4).

sleeve) or unbalanced (tip and sleeve) input signals.
Because they are electrically in parallel with the PIP in­put connectors, input signals should not be connected
to the phone jacks when certain PIP modules are in­stalled (see Section 3.3.4). The phone jacks can also
be used as “daisy chain” outputs to simplify connect­ing input signals to multiple amplifiers.

Channel 2 input should NOT be used in either
Bridge Mono or Parallel Mono mode.

Caution: The

L. Ground Lift Switch

This switch isolates or “lifts” the phone jack signal
grounds from the AC power ground. Activating the
switch inserts an impedance between the sleeve of
each phone jack and the unit’s AC ground to help pre­vent the hum that can result from a ground loop.

M. Balanced XLR Inputs

The factory-installed P.I.P.- FX provides a three-pin fe­male XLR connector for balanced input to each chan­nel. The XLR inputs are connected in parallel with the
amplifier’s phone jack inputs. Because the P.I.P.- FX
does not have any active circuitry, its XLR connectors
can also be used as “daisy chain” outputs to connect
signals from phone jack inputs to multiple amplifiers
(see Section 3.3.4). Caution: The Channel 2 input

should NOT be used in either Bridge Mono or Paral­lel Mono mode.

K. Balanced Phone Jack Inputs

Balanced ¼-inch phone jack input connectors are pro­vided on the back panel of your amplifier. The phone
jacks can be wired for either balanced (tip, ring and

Reference Manual

N. Output Jacks

A pair of versatile 5-way binding posts is provided for
the output of each channel. The 5-way binding posts
accept banana plugs, spade lugs or bare wire.

Page 9

3 Installation

3.1 Mounting

Macro-Tech amplifiers are designed for standard
19-inch (48.3-cm) rack mounting and “stack” mounting
without a cabinet. For more efficient cooling and extra
support in a rack, it is recommended that units be
stacked directly on top of each other.

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

Macro-Tech 600/1200/2400 Power Amplifiers

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

Tip:

An easy way to verify adequate cooling is to ob­serve the ODEP indicators while the amplifier is operat­ing under worst-case conditions. If the indicators dim,
additional cooling is recommended.

LEVEL LEVEL

181512

9

21

24

6

27

3

30

0

19 in

48.3 cm

SIDE VIEW

16 in

40.6 cm

SIGNAL/IOC

ODEP

181512

9

21

ON

24

6

3

0

OFF

27

30

ENABLECH1 CH2

2.5 in

6.35 cm

3.5 in

8.9 cm

Fig. 3.1 Mounting Dimensions

3.2 Cooling

NEVER block the side or front air vents. Macro-Tech
amplifiers do not need to be mounted with space be­tween them. If you must leave open spaces in a rack
for any reason, close them with blank panels to prevent
air from recycling into the front of other amplifiers. Allow
at least 35 cubic feet (1 cubic meter) per minute per
unit for the Macro-Tech 600 and 1200, and at least 45
cubic feet (1.3 cubic meters) per minute per unit for the
Macro-Tech 2400. Additional air flow may be required
when driving low impedance loads at consistently high
output levels. Refer to Section 7 for detailed information
on thermal dissipation.

17 in

43.2 cm

IMPORTANT: Be sure rear of amplifier

is securely mounted to rack.

If your rack has a front door that could block air flow to
the amplifier’s air intakes, you must provide adequate
air flow by installing a grille in the door or by pressuriz­ing the air behind the door. Wire grilles are recom­mended over perforated panels because they tend to
cause less air restriction. A good choice for pressuriz­ing 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 blows
outside air into the space between the door and in front
of the amplifiers, pressurizing the “chimney” behind the
door. This blower should not blow air into or take air out
of the space behind the amplifiers. For racks without a
door, you can evacuate the rack by mounting the
blower at the top of the rack so that air inside the cabi­net is drawn out the back (Option 2 below).

AIR

FLOW

BLOWER

(OPTION 2)

EQUIPMENT

RACK

(SIDE VIEW)

FRONT

OF

RACK

DOOR

16 in

40.6 cm

AIR

FLOW

2 in

(5 cm)

MIN.

AMPLIFIER
(TOP VIEW)

AIR

FLOW

RACK

CABINET

AIR

FLOW

BLOWER

(OPTION 1)

Fig. 3.3 Proper Air Flow in a Rack Cabinet

If the air supply is unusually dusty, you might want to
pre-filter it using commercial furnace filters to prevent
rapid loading of the unit’s own air filter. When needed,

AIR FLOW

Fig. 3.2 Top View of a Rack-Mounted Unit

Page 10 Reference Manual

the unit’s filter can be cleaned with mild dish detergent
and water (see Section 4.5).

Macro-Tech 600/1200/2400 Power Amplifiers

3.3 Wiring

This section describes the most common ways to in­stall your amplifier in a sound system. The input and
output terminals are located on the back panel. Please
use care when making connections, selecting signal
sources and controlling the output level. The load you
save may be your own! Crown assumes no liability for
damaged loads resulting from careless amplifier use or
deliberate overpowering.

CAUTION: Always remove power from the unit and
turn the level controls off while making or changing
connections.

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

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

This is very important when loudspeak-

3.3.1 Stereo (Two-Channel) Operation

In Stereo mode, installation is very intuitive: input Chan­nel 1 feeds output Channel 1, and input Channel 2
feeds output Channel 2. To put the amplifier in Stereo
mode, first turn off the amplifier, then slide the stereo/
mono switch to the center position, and properly con­nect the output wiring as shown in Figure 3.4. A pair of
5-way binding posts is provided for each channel to
facilitate easy connection of loudspeaker wires. Ob­serve correct loudspeaker polarity and be very careful
not to short the two outputs.

CAUTION: In Stereo mode, never parallel the two
outputs by directly tying them together, and never
parallel them with the output of another amplifier.

Such a connection does not result in increased power
output, but may result in overheating and premature
activation of the protection circuitry.

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

Reference Manual

Fig. 3.4 Stereo Wiring

Page 11

3.3.2 Bridge-Mono Operation

Bridge-Mono mode is intended for driving loads with a
total impedance of 4 ohms or more (If the load is less
than 4 ohms, see Section 3.3.3). Installing the amplifier
in Bridge-Mono mode is very different from the other
modes and requires special attention.

To put the amplifier in Bridge-Mono mode, turn the am­plifier off and slide the stereo/mono switch to the right
(as you face the back of the amplifier). Both outputs
receive the signal from Channel 1 with the output of
Channel 2 inverted so it can be bridged with the Chan­nel 1 output. DO NOT USE THE CHANNEL 2 INPUT or
the signal level and quality may be greatly degraded.
Keep the Channel 2 level control turned down com­pletely (counterclockwise).

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

Macro-Tech 600/1200/2400 Power Amplifiers

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

Connect the load across the Channel 1 and 2 red bind­ing posts with the positive lead from the load attaching
to the red post of Channel 1 and the negative lead of
the load attaching to the red post of Channel 2 as shown
in Figure 3.5. THE TWO BLACK BINDING POSTS ARE
NOT USED AND SHOULD NOT BE SHORTED. The
load must be balanced (neither side shorted to
ground).

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

Fig. 3.5 Bridge-Mono Wiring

Page 12 Reference Manual

Macro-Tech 600/1200/2400 Power Amplifiers

3.3.3 Parallel-Mono Operation

Parallel-Mono mode is intended for driving loads with a
net impedance of less than 4 ohms. (See Bridge-Mono
if the load is 4 ohms or greater.) Installing the amp in
Parallel-Mono mode is very different from the other
modes and requires special attention.

CAUTION: Do not attempt to operate in Stereo or
Bridge-Mono mode until the Parallel-Mono jumper
is first removed. Failure to do so will result in high
distortion and excessive heating.

To put the amplifier in Parallel-Mono mode, turn it off
and slide the stereo/mono switch to the left (as you face
the back panel). Connect the input signal to Channel 1
only. 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 to
remain lit in Parallel-Mono mode.

Install a jumper wire between the red binding posts of
both Channel 1 and 2 that is at least 14 gauge in size.
Then, connect the load to the output of Channel 1 as
shown in Figure 3.6. The positive lead from the load
connects to the red binding post of Channel 1 and the
negative lead from the load connects to the black bind­ing post of Channel 1.

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

Reference Manual

Fig. 3.6 Parallel-Mono Wiring

Page 13