CROWN 600 Micro Tech Series Professional Power Amplifiers User Manual
- June 11, 2024
- CROWN
Table of Contents
600 Micro Tech Series Professional Power Amplifiers
Micro-Tech Series Power Amplifiers
The Micro-Tech Series Power Amplifiers are a family of
commercial audio power amplifiers. The family includes six models:
Micro-Tech 600, 1200, & 2400 and Micro-Tech 601, 1201, &
2401. These amplifiers comply with part 15 of the FCC rules and the
requirements of the EMC Council Directive 89/336/EEC as amended by
92/31/EEC, and the Low Voltage Directive 73/23/EES as amended by
93/68/EEC.
Important Safety Instructions
- Read these instructions.
- Keep these instructions.
- Heed all warnings.
- Follow all instructions.
- Do not use this apparatus near water.
- Clean only with a dry cloth.
- Do not block any ventilation openings. Install.
Magnetic Field
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.
Operation Instructions
To prevent electric shock, do not remove top or bottom covers.
No user serviceable parts inside. Refer servicing to qualified
service personnel.
The Micro-Tech 2400/2401 requires Class 1 output wiring. The
Micro-Tech 600/601/ & 1200/1201 require Class 2 output wiring.
Due to line current harmonics, it is recommended to contact your
supply authority before connection.
Watch for these Symbols
The lightning bolt triangle is used to alert the user to the
risk of electric shock. The exclamation point triangle is used to
alert the user to important operating or maintenance
instructions.
Micro-Tech Series
Operation Manual
Micro-Tech 600, 1200, & 2400
Micro-Tech 601, 1201, & 2401
Obtaining Other Language Versions: To obtain information in another language
about the use of this product, please contact your local Crown Distributor. If
you need assistance locating your local distributor, please contact Crown at
574-294-8000. 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. The information provided in this
manual was deemed accurate as of the publication date. However, updates to
this information may have occurred. To obtain the latest version of this
manual, please visit the Crown website at www.crownaudio.com. Trademark
Notice: Crown, Amcron, Crown Audio and ODEP are registered trademarks of Crown
International. Grounded Bridge is a trademark of Crown International. Other
trademarks are the property of their respective owners.
Some models may be exported under the name Amcron.®
©2004 by Crown Audio®, Inc. P.O. Box 1000, Elkhart, Indiana 46515-1000 U.S.A.
Telephone: 574-294-8000
102990-8 06/04
Important Safety
Instructions
- Read these instructions. 2) Keep these instructions. 3) Heed all warnings.
- Follow all instructions. 5) Do not use this apparatus near water. 6) Clean
only with a dry cloth. 7) Do not block any 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. If 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, 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 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 damaged in any way, such as powersupply 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. 15) To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture.
page 2
Micro-Tech Series Power Amplifiers
TO PREVENT ELECTRIC SHOCK DO NOT REMOVE TOP OR BOTTOM COVERS. NO USER
SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
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.
IMPORTANT
The Micro-Tech 2400/2401 requires Class 1 output wiring. The Micro-Tech
600/601/ & 1200/1201 require Class 2 output wiring.
MAGNETIC FIELD
CAUTION! Do not locate sensitive high-gain equipment such as preamplifiers or
tape decks directly above or below the unit. Because this amplifier has a high
power density, it has a strong magnetic field which can induce hum into
unshielded devices that are located nearby. The field is strongest just above
and below the unit.
If an equipment rack is used, we recommend locating the amplifier(s) in the
bottom of the rack and the preamplifier or other sensitive equipment at the
top.
WATCH FOR THESE SYMBOLS:
The lightning bolt triangle is used to alert the user to the risk of electric
shock.
The exclamation point triangle is used to alert the user to important
operating or maintenance instructions.
FCC COMPLIANCE NOTICE
This device complies with part 15 of the FCC rules. Operation is subject to
the following two conditions: (1) This device may not cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.
CAUTION: Changes or modifications not expressly approved by the party
responsible for compliance could void the user’s authority to operate the
equipment.
NOTE: This equipment has been tested and found to comply with the limits for a
Class B digital device, pursuant to part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses, and can radiate
radio frequency energy and, if not installed and used in accordance with the
operation manual, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to
radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:
· Reorient or relocate the receiving antenna. · Increase the separation
between the equipment and receiver. · Connect the equipment into an outlet on
a circuit different from that to which the receiver is con-
nected. · Consult the dealer or an experienced radio/TV technician for help.
Operation Manual
Micro-Tech Series Power Amplifiers
Crown International, Inc.
DECLARATION of CONFORMITY
Issued By: Crown International, Inc. 1718 W. Mishawaka Road Elkhart, Indiana
46517 U.S.A.
European Representative’s Name and Address: Nick Owen 19 Clos Nant Coslech
Pontprennau Cardiff CF23 8ND United Kingdom
Equipment Type: Commercial Audio Power Amplifiers Family Name: Micro-Tech
Amplifiers Model Names: Micro-Tech 600, 1200, 2400, 601, 1201, 2401
Sue Whitfield 574-294-8289 swhitfield@crownintl.com
EMC Standards: EN 55103-1:1995 Electromagnetic Compatibility – Product Family
Standard for Audio, Video, Audio-Visual and Entertainment Lighting Control
Apparatus for Professional Use, Part 1: Emissions EN 55103-1:1995 Magnetic
Field Emissions-Annex A @ 10 cm and 1 M EN 61000-3-2:1995+A14:2000 Limits for
Harmonic Current Emissions (equipment input current 16A per phase) EN
61000-3-3:1995 Limitation of Voltage Fluctuations and Flicker in Low-Voltage
Supply Systems Rated Current 16A EN 55022:1992 + A1: 1995 & A2:1997 Limits and
Methods of Measurement of Radio Disturbance Characteristics of ITE: Radiated,
Class B Limits; Conducted, Class B EN 55103-2:1996 Electromagnetic
Compatibility – Product Family Standard for Audio, Video, Audio-Visual and
Entertainment Lighting Control Apparatus for Professional Use, Part 2:
Immunity EN 61000-4-2:1995 Electrostatic Discharge Immunity (Environment
E2-Criteria B, 4k V Contact, 8k V Air Discharge) EN 61000-4-3:1996 Radiated,
Radio-Frequency, Electromagnetic Immunity (Environment E2, Criteria A) EN
61000-4-4:1995 Electrical Fast Transient/Burst Immunity (Criteria B) EN
61000-4-5:1995 Surge Immunity (Criteria B) EN 61000-4-6:1996 Immunity to
Conducted Disturbances Induced by Radio-Frequency Fields (Criteria A) EN
61000-4-11:1994 Voltage Dips, Short Interruptions and Voltage Variation
Safety Standard: EN 60065: 1998 Safety Requirements – Audio Video and Similar
Electronic Apparatus
I certify that the product identified above conforms to the requirements of the EMC Council Directive 89/336/EEC as amended by 92/31/EEC, and the Low Voltage Directive 73/23/EES as amended by 93/68/EEC.
Signed
Larry Colburn
Title: Senior Vice President of Manufacturing
Date of Issue: January 1, 2001
Operation Manual
Due to line current harmonics, we recommend that you contact your supply authority before connection.
page 3
Table of Contents
Important Safety Instructions ……………………………. 2 Declaration of Conformity
………………………………… 3 1 Welcome ……………………………….. 5
1.1 Features ……………………………………………… 5 1.2 Unpacking Your Amplifier ……………………… 5 2
How to Use This Manual ……………….. 5 3 Setup ……………………………………. 6 3.1 Unpack Your
Amplifier …………………………. 6 3.2 Install Your Amplifier …………………………… 6 3.3 Ensure
Proper Cooling ………………………… 6 3.4 Choose Input Wire and Connectors ……….. 7 3.5
Choose Output Wire and Connectors …….. 8 3.6 Wire Your System ……………………………….. 9
3.6.1 Stereo Mode ………………………………. 9 3.6.2 Bridge-Mono Mode …………………….. 9 3.6.3
Parallel-Mono Mode …………………… 9 3.7 Set Input Sensitivity …………………………….. 10 3.8
Set Ground Lift Switch …………………………. 10 3.9 Connect to AC Mains ………………………….. 10
3.10 Startup Procedure ……………………………… 10 4 Operation ………………………………. 11 4.1
Precautions ………………………………………… 11 4.2 Controls, Indicators and Connectors ……….
12 4.2.1 Front Panel Facilities ……………………. 12 4.2.2 Rear Panel Facilites
………………………. 13
page 4
Micro-Tech Series Power Amplifiers
5 Advanced Features and Options …………………….14 5.1 Protection Systems
……………………………………………….. 14 5.1.1 ODEP ………………………………………………………….. 14 5.1.2
Ultrasonic and Radio Frequency Protection ………. 14 5.1.3 Drive Protection
……………………………………………. 14 5.1.4 Transformer Thermal Protection ……………………… 14 5.1.5
Fuses and Circuit Breakers …………………………….. 14 5.2 Accessories
…………………………………………………………. 15 5.2.1 Cooling Fan Options …………………………………….. 15 5.2.2
Input Connectors Option ………………………………. 15 5.3 Filter Cleaning
……………………………………………………… 15
6 Principles of Operation ………………………………16 6.1 Overview
…………………………………………………………….. 16 6.2 Circuit Theory ……………………………………………………… 16 6.2.1
Stereo Operation …………………………………………… 17 6.2.2 Bridge-Mono Operation
…………………………………. 18 6.2.3 Parallel-Mono Operation ……………………………….. 18
7 Troubleshooting ……………………………………..19 8 Specifications ……………………………………….20 9 AC
Power Draw and Thermal Dissipation …………..22 10 Service …………………………………………….24
10.1 Worldwide Service ……………………………………………….. 24 10.2 US and Canada Service
………………………………………… 24
10.2.1 Service at a US or Canada Service Center ………. 24 10.2.2 Factory Service
…………………………………………… 24 10.2.3 Factory Service Shipping Instructions ……………. 24 11
Warranty ……………………………………………25 Crown Factory Service Information Form
…………………………….. 27
Operation Manual
Micro-Tech Series Power Amplifiers
Operation Manual
1 Welcome
The Crown® Micro-Tech 600, 1200 and 2400 are the original industry standards
for touring amplifiers. Micro-Tech amplifiers are known around the world as
the benchmark for highdensity, ultra-pure power in a compact package. In
addition, each model gives you Crown’s legendary ODEP® protection to keep the
show going long after other amplifiers would fail.
Models MT-601, 1201 and 2401(for Japan) are identical to corresponding models
MT-600, 1200 and 2400.
Modern power amplifiers are sophisticated pieces of engineering capable of
producing extremely high power levels. They must be treated with respect and
correctly installed if they are to provide the many years of reliable service
for which they were designed.
In addition, the Micro-Tech amplifiers include a number of features which
require some explanation before they can be used to their maximum advantage.
Please take the time to study this manual so that you can obtain the best
possible service from your amplifier.
1.1 Features
· Grounded BridgeTM design delivers incredible voltage swings without
stressing output transistors. This results in significantly lower distortion
and superior reliability.
· Patented ODEP® (Output Device Emulation Protection) circuitry compensates
for overheating and overload to keep the amplifier working.
· High damping factor provides superior motion control over low-frequency
drivers for clean, accurate low end.
· Two mono modes (Bridge-Mono and Parallel-Mono) for driving a wide range of
load impedances.
· Full protection against shorted outputs, open circuits, DC, mismatched
loads, general overheating, high-frequency overloads and internal faults.
1.2 Unpacking Your Amplifier
Please unpack and inspect your amplifier for any damage that may have occurred
during transit. If damage is found, notify the transportation company
immediately. Only you can initiate a claim for shipping damage. Crown will be
happy to help as needed. Save the shipping carton as evidence of damage for
the shipper’s inspection.
We also recommend that you 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.
2 How to Use This Manual
This manual provides you with the necessary information to safely and
correctly set up and operate your amplifier. It does not cover every aspect of
installation, setup or operation that might occur under every condition. For
additional information, please consult Crown’s Amplifier Application Guide
(available online at www.crownaudio.com), Crown Tech Support, your system
installer or retailer. We strongly recommend you read all instructions,
warnings and cautions contained in this manual. Also, for your protection,
please send in your warranty registration card today. And save your bill of
sale-it’s your official proof of purchase.
page 5
3 Setup
page 6
3.1 Unpack Your Amplifier YOU WILL NEED (not supplied):
· Input wiring cables
· Output wiring cables
Rack for mounting amplifier (or a stable surface for stacking)
WARNING: Before you start to set up your amplifier, make sure you read and
observe the Important Safety Instructions found at the beginning of this
manual.
Micro-Tech Series Power Amplifiers
3.2 Install Your Amplifier
CAUTION: Before you begin, make sure your amplifier is disconnected from the
power source, with power switch in the “off” position and all level controls
turned completely down (counterclockwise).
Use a standard 19-inch (48.3 cm) equipment rack. See Figure 3.1 for amplifier
dimensions.
You may also stack amps without using a cabinet.
NOTE: When transporting, amplifiers should be supported at both front and
back.
3.3 Ensure Proper Cooling
When using an equipment rack, mount units directly on top of each other. Close
any open spaces in rack with blank panels. DO NOT block front or rear air
vents. The side walls of the rack should be a minimum of two inches (5.1 cm)
away from the amplifier sides, and the back of the rack should be a minimum of
four inches (10.2 cm) from the amplifier back panel.
Figure 3.2 illustrates standard amplifier airflow.
ODEP
CH1
CH2
POWER OFF
19 in 48.3 cm
SIDE VIEW
16 in 40.6 cm
Figure 3.1 Mounting Dimensions
3.5 in 8.9 cm
Figure 3.2 Airflow
Operation Manual
Micro-Tech Series Power Amplifiers
3 Setup
3.4 Choose Input Wire and Connectors Crown recommends using pre-built or
professionally wired, balanced line (two-conductor plus shield), 22-24 gauge
cables and connectors. Depending upon which amplifier input you choose, you
should use either 3-pin male XLR connectors, TRS phone connectors, or terminal
forks at the amplifier inputs.
Unbalanced lines may also be used but may result in noise over long cable
runs.
The amplifier input connectors not used for audio signal input may be used to
daisy-chain the audio signal to other components.
Figure 3.3 shows connector pin assignments for balanced wiring, and Figure 3.4
shows connector pin assignments for unbalanced wiring
NOTE: Custom wiring should only be performed by qualified personnel.
Figure 3.3 Balanced Input Connector Wiring
Figure 3.4 Unbalanced Input Connector Wiring
Operation Manual
page 7
3 Setup
3.5 Choose Output Wire and Con-
nectors
Crown recommends using pre-built or professionally wired, high-quality, two-
conductor, heavy gauge speaker wire and connectors. Use banana plugs, spade
lugs or bare wire for your output connectors (Figure 3.5). To prevent short
circuits, wrap or otherwise insulate exposed loudspeaker cable connectors.
Using the guidelines below, select the appropriate size of wire based on the distance from amplifier to speaker.
Distance up to 25 ft. 26-40 ft. 41-60 ft. 61-100 ft. 101-150 ft. 151-250 ft.
Wire Size 16 gauge 14 gauge 12 gauge 10 gauge 8 gauge 6 gauge
CAUTION: Never use shielded cable for output wiring.
Micro-Tech Series Power Amplifiers
Figure 3.5 Output Connections
page 8
Operation Manual
Micro-Tech Series Power Amplifiers
3 Setup
3.6 Wire Your System
3.6.1 Stereo Mode Typical input and output wiring is shown in Figure 3.6. Turn
off the amplifier, and set the Stereo/Mono mode switch on the back to Stereo.
INPUTS: Connect input wiring for both channels.
OUTPUTS: Maintain proper polarity (+/-) on output connectors.
Connect Channel 1 positive (+) speaker load to Channel 1 positive terminal of
amp; repeat for negative (-). Repeat Channel 2 wiring as for Channel 1.
3.6.2 Bridge-Mono Mode Typical input and output wiring is shown in Figure 3.6.
Turn off the amplifier, and set the Stereo/Mono mode switch on the back to
Bridge Mono.
INPUTS: Connect input wiring to Channel 1 only.
OUTPUTS: Connect the speaker across the positive (red) terminals of each
channel. Do not use the negative terminals when the amp is being operated in
Bridge-Mono mode. The load must be balanced so neither lead is connected to
ground.
CAUTION: Connect only balanced equipment (meters, switches, etc.) to the
Bridge-Mono output. Both sides of the line must be isolated from the input
grounds or oscillations may occur.
NOTE: To prevent distortion and low levels, the Channel 2 level control should
be set fully counter-clockwise when operating the amplifier in Bridge-Mono
mode.
NOTE: Crown provides a reference of wiring pin assignments for commonly used
connector types in the Crown Amplifier Application Guide (Section 1.21.)
available at www.crownaudio.com.
3.6.3 Parallel-Mono Mode Typical input and output wiring is shown in Figure
3.6. Turn off the amplifier, and set the Stereo/Mono mode switch on the back
to Parallel Mono. Turn down the Channel 2 level control.
INPUTS: Connect input wiring to Channel 1 only.
OUTPUTS: Connect positive (+) speaker load to amplifier Channel 1 red (+)
binding post. Connect negative (-) speaker load to amplifier Channel 1 black
(-) binding post. Add a 14 gauge (or larger) jumper wire between the red (+)
binding posts of both channels 1 and 2.
CAUTION: When the amplifier is wired for Parallel-Mono mode, do not change the
rear switch to Stereo or Bridge-Mono. Doing that will result in inefficient
operation, high distortion and excessive heating.
NOTE: Crown provides a reference of wiring pin assignments for commonly used
connector types in the Crown Amplifier Application Guide (Section 1.21.)
available at www.crownaudio.
Operation Manual
Figure 3.6 Three System Connection Methods
page 9
3 Setup
SENSITIVITY SWITCH INSIDE ACCESS HOLE
1.4 V 26 dB 0.77 V
THIS AMPLIFIER IS EQUIPPED WITH SELECTABLE INPUT SENSITIVITY. REMOVE COVER PLATE (ABOVE) TO ACCESS SENSITIVITY SWITCH.
BALANCED INPUT WIRING
+ TIP RING
GND SLEEVE
CH-2
56 7
4
8
3
9
2
10
1
11
0
12
GAIN
INPUT
INPUT GROUND LIFT LIFT (AFFECTS PHONE INPUTS ONLY.)
INPUT
(MONO)
CH-1
56 7
4
8
3
9
2
10
1
11
0
12
GAIN
UNBALANCED INPUT WIRING
+ TIP
GND SLEEVE
GROUND LIFT SWITCH
Figure 3.7 Input Sensitiviy and Ground Lift Switches
3.7 Set Input Sensitivity
The three-position input sensitivity switch is located inside the amplifier
behind the MT-XLR module (Figure 4.2 letter “I”). The switch is set at the
factory to a sensitivity of 0.775 volt for standard 1 kHz power into 8 ohms.
(Factory setting for International versions is 1.4 V.) If desired, the
sensitivity can be switched to 1.4 volts for standard 1 kHz power into 8 ohms,
or a voltage gain of 26 dB. The 26 dB gain setting is equivalent to a
sensitivity of 2.1 volts for the Micro-Tech 600, 2.5 volts for the Micro-Tech
1200 and 3.2 volts for the Micro-Tech 2400.
To change the input sensitivity:
1. Remove the back panel cover plate (or input connector accessory).
2. Locate the access hole for the sensitivity switch inside the chassis
opening (Figure 3.7). The sensitivity switch will not be visible because it is
mounted below the hole. Use your little finger to reach it.
3. Set the switch to the desired position noted on the label beside the
access hole.
4. Replace the back panel cover plate (or input connector accessory).
3.8 Set Ground Lift Switch
The ground lift switch (Figure 3.7) is located on the back panel and can
isolate the input signal grounds from the AC (chassis) ground. It affects only
the phone jack inputs and has no effect on accessory input connectors. Sliding
the switch to the left isolates or “lifts” the grounds by placing an impedance
between the sleeve of each phone jack and the AC ground.
The Micro-Tech 2400 has two reset switches for its high-voltage power
supplies. Refer to the Troubleshooting Section in the unusual event of a
tripped breaker.
page 10
Micro-Tech Series Power Amplifiers
3.9 Connect to AC Mains Connect your amplifier to the AC mains power source
(power outlet) with the supplied AC power cordset.
WARNING: The third prong of the power connector (ground) is an important
safety feature. Do not attempt to disable this ground connection by using an
adapter or other methods.
Amplifiers don’t create energy. The AC mains voltage and current must be
sufficient to deliver the power you expect. You must operate your amplifier
from an AC mains power source with not more than 10% variation above or below
the amplifier’s specified line voltage and within the specfied frequency
requirements (indicated on the amplifier’s back panel label). If you are
unsure of the output voltage of your AC mains, please consult your
electrician.
3.10 Startup Procedure Use the following procedure when first turning on your
amplifier:
1. Turn down the level of your audio source.
2. Turn down the level controls of the amplifier.
3. Turn on the “Power” switch. The Power indicator should glow.
4. Turn up the level of your audio source to an optimum level.
5. Turn up the Level controls on the amplifier until the desired loudness or
power level is achieved.
6. Turn down the level of your audio source to its normal range.
If you ever need to make any wiring or installation changes, don’t forget to
disconnect the power cord.
For help with determining your system’s optimum gain structure (signal levels)
please refer to the Crown Amplifier Application Guide, available online at
www.crownaudio.com.
Operation Manual
Micro-Tech Series Power Amplifiers
4 Operation
4.1 Precautions Your amplifier is protected from internal and external faults,
but you should still take the following precautions for optimum performance
and safety:
1. Before use, your amplifier first must be configured for proper operation,
including input and output wiring hookup and Stereo/Mono-switch setting.
Improper wiring can result in serious operating difficulties. In Parallel-Mono
mode, a jumper is used between the red (+) Channel 1 and 2 output binding
posts. To prevent distortion and overheating, remove this jumper for Bridge-
Mono and Stereo modes.
For information on wiring and configuration, please consult the Setup section
of this manual or, for advanced setup techniques, consult Crown’s Amplifier
Application Guide available online at www.crownaudio.com.
2. Use care when making connections, selecting signal sources and controlling
the output level. The load you save may be your own!
3. Do not short the ground lead of an output cable to the input signal
ground. This may form a ground loop and cause oscillations.
4. Never connect the output to a power supply, battery or power main.
Electrical shock may result.
5. Tampering with the circuitry, or making unauthorized circuit changes may
be hazardous and invalidates all agency listings.
6. Do Not operate the amplifier with the ODEP LEDs turning off.
7. Do Not overdrive the mixer, which will cause clipped signal to be sent to
the amplifier. Such signals will be reproduced with extreme accuracy, and
loudspeaker damage may result.
8. Do Not operate the amplifier with less than the rated load impedance. Due
to the amplifier’s output protection, such a configuration may result in
premature clipping and speaker damage.
Remember: Crown is not liable for damage that results from overdriving other
system components.
Operation Manual
page 11
4 Operation
4.2 Controls, Indicators and Connectors
4.2.1 Front Panel Facilities
A. Filter Grille
Supports and protects the dust filter (B). To clean the dust filter, detach
the grille by removing the three screws that hold it in place.
B. Dust Filter
Removes large particles from the air drawn by the cooling fan. Check the
filter regularly to prevent clogging. The filter can be cleaned by soaking in
a mild detergent (e.g. dishwashing liquid).
C. ODEP Indicators (Output Device
Emulation Protection)
During normal operation, these amber indicators glow brightly to show that
reserve thermodynamic energy is present. They dim proportionally as energy
reserves decrease. In the rare event that energy reserves are depleted, the
ODEP indicators turn off and the protection circuitry proportionally limits
output drive so the amplifier can safely continue operating even under extreme
conditions. These indicators also help identify more unusual operating
conditions (see Section 5.1.1 on ODEP and Section 7 on Troubleshooting).
Micro-Tech Series Power Amplifiers
D. Enable Indicator
Lights when the amplifier is on. AC power is available and the low-voltage
power supply and fan are operational. Does not indicate the status of the
high-voltage power supply (see Section 6 on Troubleshooting).
E. Power Switch
Amplifier is on when the switch is in the “on” position. When turned on, the
output is muted for approximately four seconds to protect your system from
start-up transients.
A
B
page 12
ODEP
CH1
CH2
POWER OFF
C
C
Figure 4.1 Front Panel Indicators and Grille
D
E
Operation Manual
Micro-Tech Series Power Amplifiers
4 Operation
4.2.2 Rear Panel Facilities
F. Power Cord
All units are shipped with an approprate plug and cord for the required AC
voltage.
G. Stereo/Mono Modes Switch
· Use Stereo mode for normal two-channel operation.
· Use Bridge-Mono mode to drive a single channel with a load impedance of at
least 4 ohms.
· Use Parallel-Mono mode to drive a single channel with a load impedance less
than 4 ohms.
Important: Turn off the amplifier before changing the Stereo/Mono modes
switch.
H. Reset Switches (Micro-Tech 2400 only)
The Micro-Tech 2400 has two push-button reset swiches on the back panel that
are used to reset the circuit breakers for the high-voltage power supplies.
Refer to Section 5.1.5 in the rare event of a tripped breaker.
I. MT-XLR Module
This module provides two balanced XLR inputs. Because the MT-XLR connectors
are in parallel with the amplifier’s built-in phone connectors, an input
signal fed to either input can be fed to another amplifier from the unused
connector for that channel. If you prefer to use barrier block inputs instead,
order the MT-BB accessory (see Section 5.2).
Input Sensitivity Switch
The three-position input sensitivity switch (Figure 4.2) is located inside the
amplifier behind the MTXLR module (I). See Section 3.7 for details.
J. Level Controls
Used to set the amplifier’s output levels. These controls are on the back
panel to prevent tampering. Be sure to turn down the Channel-2 level control
(fully counterclockwise) when operating in Bridge-Mono or Parallel-Mono mode.
K. Balanced Phone Jack Inputs
A balanced ¼-inch phone jack input is provided for each channel. The jacks may
be used with either
balanced (tip, ring and sleeve) or unbalanced (tip and sleeve) lines (refer to
Figure 3.5). Balanced XLR ijnputs for each channel are provided with the MT-
XLR module. Barrier-block input connectors are available with the MT-BB
accessory (see Section 5.2.2). Caution: Do not use the Channel-2 input in
either mono mode.
L. Ground Lift Switch
Used to isolate the phone jack signal grounds from the AC power (chassis)
ground. Moving the switch to the “lift” position helps prevent the hum
associated with ground loops. Sliding the switch to the left isolates or
“lifts” the grounds by placing an impedance between the sleeve of each phone
jack and the AC ground.
M. Output Jacks
A pair of versatile binding posts is provided for output connection to each
channel. Loudspeakers can be easily connected using banana plugs, spade lugs
or bare wire (European models do not accept banana plugs). See Section 3.5.
PUSH TO RESET
MODEL: MICRO-TECH 2400 SERIES AC VOLTS: 120 AMPS: 17 60 Hz
MAXIMUM OUTPUT: 900 WATTS PER CHANNEL INTO 2 OHMS AT 1 KHz WITH NO MORE THAN
0.1% THD.
REG. U.S. PAT. OFF. 4,330,809 4,611,180
PARALLEL MONO
STEREO
BRIDGE MONO
CAUTION: TURN OFF AMPLIFIER BEFORE CHANGING THIS SWITCH!
CAUTION: THIS COVER IS NECESSARY FOR EFFICIENT COOLING OF THE AMPLIFIER. REMOVE ONLY TO ACCESS GAIN SWITCH.
THIS AMPLIFIER IS EQUIPPED WITH SELECTABLE INPUT SENSITIVITY. REMOVE COVER PLATE (ABOVE) TO ACCESS SENSITIVITY SWITCH.
BALANCED INPUT WIRING
+ TIP RING
GND SLEEVE
CH-2
56 7
4
8
3
9
2
10
1
11
0
12
GAIN
INPUT
INPUT GROUND LIFT LIFT (AFFECTS PHONE INPUTS ONLY.)
INPUT
(MONO)
CH-1
56 7
4
8
3
9
2
10
1
11
0
12
GAIN
UNBALANCED INPUT WIRING
+ TIP
GND SLEEVE
OUTPUTS
CLASS 1 OUTPUT WIRING REQUIRED.
CH-2
CH-1
WARNING: TO REDUCE THE RISK OF FIRE OR
ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT
TO RAIN OR MOISTURE.
® INTERNATIONAL, INC. ELECTRONIC EQUIPMENT
ELKHART, IN 46517 MADE IN U.S.A.
0000
SERIAL NUMBER
000000
BRIDGE-MONO WIRING 1 TURN AMPLIFIER OFF.
2 SET STEREO/MONO
SWITCH TO BRIDGE-MONO.
3 OUTPUT ACROSS RED TERMINALS ONLY. (CH-1 IS POSITIVE.)
PARALLEL-MONO WIRING
1 TURN AMPLIFIER OFF.
2 SET STEREO/MONO
SWITCH TO
PARALLEL-MONO.
3 ADD JUMPER (14
GAGE OR LARGER)
ACROSS RED
TERMINALS.
4 OUTPUT ACROSS CH-1 TERMINALS ONLY.
Operation Manual
F
GH
IJ K L
KJ
Figure 4.2 Rear Panel Connectors and Controls
MM
page 13
5 Advanced Features and Options
NOTE: For detailed information about these Crown amplifier features, please
consult the Crown Amplifier Application Guide, available on the Crown website
at www.crownaudio.com.
5.1 Protection Systems
Your Crown amplifier provides extensive protection and diagnostic
capabilities, including ODEP, ultrasonic/RF protection, drive protection, and
power supply fuses or breakers.
5.1.1 ODEP
Crown invented ODEP to prevent amplifier shutdown during demanding operation,
and to increase the efficiency of the output circuitry.
To do this, Crown measured the safe operating area (SOA) of each output
transistor before installing it in an amplifier. Next, Crown designed
intelligent circuitry to simulate the instantaneous operating conditions of
those output transistors. Its name describes what it does: Output Device
Emulation Protection or ODEP. In addition to simulating output transistor
operating conditions, it compares their operation to their known SOA. If ODEP
sees that more power will be asked of the output devices than they can
deliver, ODEP immediately limits the drive level until it falls within the
SOA. Limiting is proportional and kept to an absolute minimum — only what is
required to prevent output transistor damage.
This level of protection enables Crown to increase output efficiency to never-
beforeachieved levels while greatly increasing reliability. The front-panel
ODEP indicators show whether the amplifier is functioning correctly or whether
ODEP is limiting the drive level.
5.1.2 Ultrasonic and Radio Frequency Protection
Micro-Tech amplifiers have a controlled slew rate. This means that their
design puts a limit on the frequencies they can reproduce. The
page 14
Micro-Tech Series Power Amplifiers
controlled slew rate has no effect on audio performance because the high-
frequency limit is well above 20 kHz. This approach protects the amplifier and
tweeters from radio frequencies. An amplifier’s slew rate only needs to be
large enough to deliver the maximum voltage at the highest required frequency
— higher slew rates actually let the amplifier reproduce undesirable
frequencies.
5.1.3 Drive Protection
This system temporarily removes drive from the output stages to protect the
amplifier and its loads, and prevents oscillation. Drive protection can be
activated in two situations. First, if dangerous subsonic frequencies or
direct current (DC) is detected in the amplifier’s output, drive protection
will activate. The amplifier resumes normal operation when it no longer
detects dangerous output. Activating this protection is very unlikley, but
improper source signals like subsonic square waves or a severely clipped
signal can activate this system.
Second, the amplifier’s fault protection system puts the affected channel into
drive protection mode in rare situations where heavy commonmode current is
detected in its output. The amplifier should never output heavy commonmode
current unless its circuitry is damaged. Activating drive protection helps
prevent further damage.
5.1.4 Transformer Thermal
Protection
This activates in the rare case where the unit’s transformer temperature rises
to unsafe levels. Then the amplifier will remove power from the affected
channel’s high-voltage power supply, which puts the channel in drive
protection mode. The channel will return to normal operation after its
transformer cools to a safe temperature.
A transformer can overheat during very severe conditions: higher than rated
output levels, excessively low-impedance loads, and unreasionably high input
signals.
Micro-Tech amplifiers keep working under conditions where other amplifiers
would fail. But even when a Micro-Tech’s limits are exceeded, it will still
protect itself — and your investment — from damage.
5.1.5 Fuses and Circuit Breakers 120 VAC, 60 Hz models and all Micro-Tech
2400s have an internal fuse that protects the low-voltage power supply and
cooling fan. The high-voltage power supplies for the Micro-Tech 600 and 1200
are protected by internal fuses, while the power supplies for the Micro-Tech
2400 high-voltage supplies are protected by circuit breakers.
With rated loads and output levels, the fuses (or circuit breakers) should
shut down the amplfiier only in the rare instance of a catastrophic failure.
ODEP protection keeps the amplifier operational under most other severe
conditions. The fuses (or circuit breakers) can also shut down the amplifier
if extremely lowimpedance loads and high output levels result in current draw
that exceeds their rating. Again, this should be possible only when operating
outside rated conditions, as when the amplifier is used to drive a 1-ohm load
in Stereo mode, or when an input signal is clipped severely.
Micro-Tech amplifiers do not blow their fuses or trip their breakers unless
something is wrong. In the rare event that an internal fuse blows, please
refer the unit to a qualified technician. If a breaker in a Micro-Tech 2400
trips, try to identify and correct the problem before resetting the breakers.
If the problem persists, refer the unit to a qualified technician.
Operation Manual
Micro-Tech Series Power Amplifiers
5 Advanced Features and Options
5.2 Accessories
5.2.1 Cooling Fan Options Every Micro-Tech amplifier has a built-in
highvelocity fan that provides optimum cooling. Two optional replacement fan
blades are available for special cooling requirments. Crown part C 6594-3 is a
quieter, low-velocity fan blade that in many cases can provide adequate
cooling. Crown part C 6593-5 is a reverse air flow fan blade which changes the
direction of the air flow in and out of the amplifier (not recommended for the
Micro-Tech 2400).
Important: The optional replacement fan blades should only be installed by a
qualified technician.
5.2.2 Input Connectors Option The MT-BB is an accessory panel that provides
barrier-block input connectors. An MT-BB accessory might be desirable in
applications requiring bare wire connections. It can also be used to daisy-
chain an input signal from one amplifier to another, just like the MT-XLR.
The MT-BB must be installed at an authorized service center or the Crown
factory.
5.3 Filter Cleaning
A dust filter is provided on the air intake to the cooling system (Figure 4.1,
letter “B”). If this filter becomes clogged, the unit will not cool as
efficiently as it should and may produce lowerthan-normal output levels due to
high heat-sink temperature.
To remove the filter, use a phillips screwdriver to remove the three screws
that hold the front grille in place. Wash the filter with mild dishwashing
detergent and warm water. Be sure to dry the filter before installing it.
Replacement filters may be ordered from the factory.
Dust filters are not 100% efficient. So, depending on the local environment,
the internal heat sinks of the amplifier will benefit from periodic cleaning
by a qualified technician. Internal cleaning information is available from our
Technical Support Group.
Figure 5.1 MT-BB Input Panel Accessory
Operation Manual
page 15
6 Principles of Operation
6.1 Overview
Micro-Tech amplifiers incorporate several technological advancements including
real-time computer simulation of output transistor stress, low-stress output
stages and an advanced heat sink embodiment.
Custom circuitry is incorporated to limit temperature and current to safe
levels making it highly reliable and tolerant of faults. Unlike many lesser
amplifiers, it can operate at its voltage and current limits without self-
destructing.
Micro-Tech amplifiers are protected from all common hazards that plague high-
power amplifiers including shorted, open or mismatched loads; overloaded power
supplies; excessive temperature, chain-destruction phenomenon, input overload
and high-frequency blowups. The unit protects loudspeakers from input and
output DC, as well as turn-on and turn-off transients.
Real-time computer simulation is used to create an analogue of the junction
temperature of the output transistors (hereafter referred to as the output
devices). Current is limited only when the device temperature becomes
excessive–and only by the minimum amount required). This patented approach
called Output Device Emulation Protection (or ODEP) maximizes the available
output power and protects against overheating–the major cause of device
failure.
Micro-Tech Series Power Amplifiers
Crown also invented the four-quadrant topology used in the output stages of
each MicroTech amplifier (see Figure 6.1). This special circuitry is called
the Grounded Bridge. It makes full use of the power supply by delivering peak-
to-peak voltages to the load that are twice the voltage seen by the output
devices.
As its name suggests, the Grounded Bridge topology is referenced to ground.
Composite devices are constructed as gigantic NPN and PNP devices to handle
currents which exceed the limits of available devices. Each output stage has
two composite NPN devices and two composite PNP devices.
The devices connected to the load are referred to as “high-side NPN and PNP”
and the devices connected to ground are referred to as “lowside NPN and PNP.”
Positive current is delivered to the load by increasing conductance
simultaneously in the high-side NPN and lowside PNP stage, while decreasing
conductance of the high-side PNP and low-side NPN.
The two channels may be used together to double the voltage (Bridge-Mono) or
current (Parallel-Mono) presented to the load. This feature gives you
flexibility to maximize power available to the load.
A wide bandwidth, multiloop design is used for state-of-the-art compensation.
This produces ideal behavior and results in ultra-low distortion values.
Aluminum extrusions have been widely used for heat sinks in power amplifiers
due to their low cost and reasonable performance. But measured on a watts per
pound or watts per volume basis, the extrusion technology doesn’t perform
nearly as well as the heat sink technology developed for Micro-Tech
amplifiers.
The heat sinks in a Micro-Tech amplifier are fabricated from custom convoluted
fin stock that provides an extremely high ratio of area to volume, or area to
weight. All power devices are mounted directly to massive heat spreaders that
are electrically at the Vcc potential. Making the heat spreaders electrically
alive improves thermal performance by eliminating the insulating interface
underneath each power device. The chassis itself is also used as part of the
thermal circuit to maximize utilization of the available resources.
6.2 Circuit Theory
Each channel is powered by its own power transformer T100 or T200. Both
channels share a common low-voltage supply. The secondary output of T100 is
full-wave rectified by D109 and is filtered by a large computer grade
capacitor. A thermal switch embedded in the transformer protects it from
overheating.
The low-voltage fanformer is rectified by diodes D1, D2, D3 and D4 to generate
an unregulated 24 volts. Monolithic regulators U1 and U2 provide a regulated
±15 volts.
page 16
Operation Manual
Micro-Tech Series Power Amplifiers
6 Principles of Operation
6.2.1 Stereo Operation For simplicity, the discussion of Stereo operation will
refer to one channel only. Mono operation will be discussed later. For
specific circuit references, see the block diagram in Figure 6.1.
The signal at the ¼-inch phone jack input passes directly to the balanced gain
stage (U104-A and U104-B). The balanced gain stage causes balanced to single-
ended conversion using a difference amplifier. From there, gain can be
controlled with a potentiometer. The error amp (U104-C) amplifies the
difference between the output signal and the input signal from the gain pot,
and drives the voltage translator stage.
From the error amp, the voltage translator stage routes the signal to the Last
Voltage Amplifiers (LVAs) based on signal polarity. The +LVA
(Q105) and the LVA (Q110), with their pushpull effect through the bias servo
Q318, drive the fully complementary output stage.
The bias servo Q318 is thermally coupled to the heat sink and sets the
quiescent bias current in the output stage to lower the distortion in the
crossover region of the output signal. D301, D302, D303, and D304 remove the
charge on the unused portion of the output stage based on the polarity of the
output signal.
With the voltage swing provided by the LVAs, the signal then gains current
amplification through the Darlington emitter-follower output stage.
The bridge-balanced circuit (U104-D) receives a signal from the output of the
amplifier and compares it to the signal at the Vcc supply. The bridge-balanced
circuit then develops a voltage
to drive the bridge-balanced output stage. This results in the Vcc supply
having exactly one half of the output voltage added to their quiescent
voltage. D309, D310, D311 and a trimmer resistor set the quiescent current
point for the bridge-balanced output stage.
The protection mechanisms that affect the signal path are implemented to
protect the amplifier under real-world conditions. These conditions are high
instantaneous current, excessive temperature, and output device operation
outside safe conditions.
Q107 and Q108 sense output current and act as a common current limiter. When
instantaneous current exceeds the design criteria, the limiters remove the
drive from the LVAs to limit output current to safe levels.
Operation Manual
Figure 6.1 Circuit Block Diagram
page 17
6 Principles of Operation
To further protect the output stages, the patented ODEP circuitry is used. It
produces an analog output proportional to the always changing die temperature
of the output transistor. This output controls the translator stage previously
mentioned, removing any further drive that may exceed the safe operating area
of the output stage.
Thermal sensors S100 and S200 give the ODEP circuits vital information on the
operating temperature of the heat sink on which the output devices are
mounted.
Should the amplifier fail in a way that would cause DC across the output lead,
the DC protection circuit senses this on the negative feedback loop and shuts
down the output stage drive until the DC is removed.
6.2.2 Bridge-Mono Operation By setting the back panel stereo/mono switch to
Bridge-Mono, you can convert a Micro-Tech amplifier for bridged-mono
operation. With a signal applied to the channel 1 input and the load connected
between the positive (+) output terminals, twice the voltage can be delivered
to the load.
The channel 1 output feeds the channel 2 error amp U204-A. The signal feeding
channel 2 is inverted so the channel 2 output will have the
Micro-Tech Series Power Amplifiers
opposite polarity of channel 1. This makes it possible to deliver twice as
much voltage to the load while the protection mechanisms for each channel
continue to work independently.
6.2.3 Parallel-Mono Operation With the stereo/mono switch set to ParallelMono,
the output of channel 2 is paralleled with that of channel 1. A suitable
jumper capable of handling high current must be connected across the positive
(+) output terminals to gain the benefits of this operating mode.
The signal path for channel 1 is the same as previously discussed, except that
channel 1 also drives the output stage of channel 2. The balanced input, error
amp, translators, and LVAs of channel 2 are disconnected and no longer control
the channel 2 output stage. The channel 2 output stage and protection
mechanisms are also coupled through S1 and function as one.
In Parallel-Mono mode, the amplifier can deliver twice the current of a single
channel. Because the channel 2 ODEP circuit is coupled through S1, the
amplifier gains additional protection if a fault occurs in the channel 2
output stage. The channel 2 ODEP circuit will limit the output of both output
stages by removing the drive from the channel 1 voltage translator.
page 18
Operation Manual
Micro-Tech Series Power Amplifiers
7 Troubleshooting
OTHER POSSIBLE CONDITIONS TO BE AWARE OF:
CONDITION: Normal operation.
The Enable (Power) LED is on, and the ODEP LEDs are on or flickering.
ODEP LEDs on indicates a high energy reserve. An ODEP LED flickering means
that the energy reserve for the affected channel is dipping.
CONDITION: Normal LED display but distorted sound.
POSSIBLE REASON:
· Load is wired incorrectly or Stereo/Mono mode switch is set incorrectly.
Check both.
· Input signal level is too high. Turn down your amplifier level controls, or
turn down the input signal, until the clip LED goes out.
Check mixer levels and gain staging, mixer clip lights, and pads built into
microphones.
CONDITION: Normal LED display but no sound.
POSSIBLE REASON:
· Input signal level is very low. · Level controls are turned down. · Input
cable broken or not plugged in. · Speakers not connected. · The amplifier
output level is so high that the
breaker has tripped. Try to identify and correct the problem before resetting
the breaker. If the problem persists, refer the unit to an authorized Crown
Service Center. · The amplifier output is shorted. First disconnect your
speakers from the affected channel(s) one by one to determine if one of the
loads is shorted.
Operation Manual
CONDITION: Enable LED on, ODEP LEDs off, no sound. Low-voltage power supply
and fan are still working. POSSIBLE REASON: · Transformer thermal protection
has activated.
Amplifier will come back on automatically when it cools. · ODEP reserves have
been depleted and the amplifier is about to activate protection. · High-
voltage power supply fuse or breaker has blown. Check for shorts in the
speaker lines. Avoid loads of 1 ohm or less. Let the amplifier cool down, then
reset the breaker (Micro-Tech 2400 only).
CONDITION: All LEDs off. POSSIBLE REASON: · The amplifier has lost power. ·
The amplifier is not plugged into the power
receptacle. · The amplifier’s circuit breaker has tripped.
Allow the amplifier to cool; check for shorts in the speaker lines; remove
excessive loads. Then reset the breaker. · The amplifier has blown its
internal fuse for the low-voltage power. supply. Refer the unit to a qualified
technician. · The power switch is off.
page 19
8 Specifications
Minimum Guaranteed Power
120 VAC, 60 Hz Units, Stereo mode, per channel, both channels driven
1 kHz with 0,1% THD Stereo, 2 ohms (per ch.) Stereo, 4 ohms (per ch.) Stereo,
8 ohms (per ch.)
120 VAC, 60 Hz Units, Bridge mono mode
1 kHz with 0.1% THD Bridge mono, 4 ohms Bridge mono, 8 ohms Bridge mono, 16
ohms
120 VAC, 60 Hz Units, Parallel mono mode
1 kHz with 0.1% THD Parallel mono, 1 ohm Parallel mono, 2 ohms Parallel mono,
4 ohms
Performance
Frequency Response (at 1 watt, 20Hz – 20 kHz)
Phase Response (at 1 watt, 20Hz – 20 kHz)
Signal to Noise Ratio below full bandwidth power 20 Hz to 20 kHz A-weighted
Total Harmonic Distortion (THD) at rated power, from 20 Hz to 20 kHz
Intermodulation Distortion (IMD) 60 Hz and 7 kHz at 4:1, from 163 milliwatts
to full bandwidth power
Damping Factor: 10 Hz to 400 Hz
Crosstalk (below rated power, 20 Hz to 20 kHz)
Common Mode Rejection (CMR) (20 Hz to 1 kHz)
DC Output Offset (Shorted input)
Input Impedance (nominally balanced, nominally unbalanced)
Load Impedance (Note: Safe with all types of loads) Stereo Bridge Mono
Parallel Mono
MT-600
400 W 325 W 220 W
750 W 655 W 450 W
700 W 665 W 450 W MT-600 ± 0.1 dB ±10°
100 dB >105 dB
0.1%
< 0.05% >1000 > 60 dB > 70 dB ±10 mV 20 k ohms, 10 k ohms
2-16 ohms 4 -16 ohms 1-4 ohms
page 20
Micro-Tech Series Power Amplifiers
MT-1200
675 W 480 W 310 W
1,300 970 W 620 W
1,300 W 965 W 620 W MT-1200 ± 0.1 dB ±10°
100 dB >105 dB
0.1%
< 0.05% >1000 > 60 dB > 70 dB ±10 mV 20 k ohms, 10 k ohms
2-16 ohms 4 -16 ohms 1-4 ohms
MT-2400
1,050 W 800 W 520 W
2,070 W 1,585 W 1,035 W
2,080 W 1, 605 W 1, 035 W MT-2400 ± 0.1 dB ±10°
100 dB >105 dB
0.1%
< 0.05% >1000 > 60 dB >70 dB ±10 mV 20 k ohms, 10 k ohms
2-16 ohms 4 -16 ohms 1-4 ohms
Operation Manual
Micro-Tech Series Power Amplifiers
8 Specifications
Performance Voltage Gain (at maximum level setting, ± 0.5 dB)
26dB sensitivitiy 0.775V sensitivity 1.4V sensitivity Required AC Mains
(country specific) Power Draw at Idle Cooling
Dimensions: Width, Height, Depth
Weight (120VAC, 60-Hz units) Net Weight Shippping Weight
Weight (International units) Net Weight Shipping Weight
MT-600
MT-1200
MT-2400
26 dB 35.0 dB 30.0 dB
50/60 Hz, 100 – 240 VAC (±10%)
90 watts
Flow-through ventilation from front to side panels. Internal heat sinks with
forced air
cooling.
EIA Standard 19 in. (48.3 cm) x 3.5 in. (8.9 cm) x 16 in. (40.6 cm)
26 dB 36.0 dB 31.0 dB
50/60 Hz, 100 – 240 VAC (±10%)
90 watts
Flow-through ventilation from front to side panels. Internal heat sinks with
forced air
cooling.
EIA Standard 19 in. (48.3 cm) x 3.5 in. (8.9 cm) x 16 in. (40.6 cm)
26 dB 38.0 dB 33.0 dB
50/60 Hz, 100 – 240 VAC (±10%)
90 watts
Flow-through ventilation from front to side panels. Internal heat sinks with
forced air
cooling.
EIA Standard 19 in. (48.3 cm) x 3.5 in. (8.9 cm) x 16 in. (40.6 cm)
36 lb 4 oz (16.5 kg) 41 lb 2 oz (18.7 kg)
41 lb 1 oz (18.6 kg) 45 lb 3 oz (20.5 kg)
46 lb 14 oz (21.3 kg) 55 lb 12 oz (25.3 kg)
38 lb 7 oz (17.9 kg) 44 lb 2 oz (20.0 kg)
41 lb 0 oz (18.6 kg) 45 lb 4 oz (20.5 kg)
47 lb 9 oz (21.6 kg) 56 lb 6 oz (25.6 kg)
Operation Manual
page 21
9 AC Power Draw and Thermal Dissipation
This section provides detailed information about the amount of power and
current drawn from the AC mains by Micro-Tech amplifiers and the amount of
heat produced under various conditions. The calculations presented here are
intended to provide a realistic and reliable depiction of the amplifiers. The
following assumptions or approximations were made: · The amplifier’s available
channels are loaded, and full power is being delivered. · Amplifier efficiency
at standard 1 kHz power is estimated to be 65%. · Typical quiescent power draw
for the MicroTech 600 is 65 watts; typical quiescent power draw for the Micro-
Tech 1200 and 2400 is 80 watts. · Quiescent thermal dissipation equals 222
btu/hr at 65 watts and 273 btu/hr at 80 watts. · The estimated duty cycles
take into account the typical crest factor for each type of source material. ·
Duty cycle of pink noise is 50%. · Duty cycle of highly compressed rock n’ roll midrange is 40%. · Duty cycle of rockn’ roll is 30%. · Duty cycle of
background music is 20%. · Duty cycle of continuous speech is 10%. · Duty
cycle of infrequent paging is 1%.
page 22
Micro-Tech Series Power Amplifiers
Here are the equations used to calculate the data presented in Figures 9.1, 9.2 and 9.3:
AC Mains Power Draw (watts)
=
Total output power with all channels driven (watts)
x
Duty Cycle
Amplifier Efficiency (.65)
Quiescent Power Draw (watts)
The quiescent power draw figures provided in the opposite column are typical and include power drawn by the fan. The following equation converts power draw in watts to current draw in amperes:
AC Mains Power
Current Draw (amperes)
=
Draw (watts)
AC Mains Voltage
x
Power Factor (.83)
The power factor of 0.83 is needed to compensate for the difference in phase between the AC mains voltage and current. The following equation is used to calculate thermal dissipation:
( ) Thermal
Dissipation =
Total output power with all channels driven (watts)
x
Duty Cycle
x
.35
Quiescent Power + Draw (watts)
x 3.415
(btu/hr)
Amplifier Efficiency (.65)
The constant 0.35 is inefficiency (1.000.65) and the factor 3.415 converts watts to btu/hr. Thermal dissipation in btu is divided by the constant 3.968 to get kcal. If you plan to measure output power under real-world conditions, the following equation may also be helpful:
( ) Thermal
Dissipation =
Total measured output power from all channels (watts)
x
.35
Quiescent Power + Draw (watts)
x 3.415
(btu/hr)
Amplifier Efficiency (.65)
Operation Manual
Micro-Tech Series Power Amplifiers
9 AC Power Draw and Thermal Dissipation
Figure 9.1 Micro-Tech 600 Power Draw, Current Draw
and Thermal Dissipation at Various Duty Cycles
Figure 9.2 Micro-Tech 1200 Power Draw, Current Draw and Thermal Dissipation at
Various Duty Cycles
Figure 9.3 Micro-Tech 2400 Power Draw, Current Draw and Thermal Dissipation at
Various Duty Cycles
Operation Manual
page 23
10 Service
page 24
Crown amplifiers are quality units that rarely require servicing. Before
returning your unit for servicing, please contact Crown Technical Support to
verify the need for servicing.
This unit has very sophisticated circuitry which should only be serviced by a
fully trained technician. This is one reason why each unit bears the following
label:
CAUTION: To prevent electric shock, do not remove covers. No user serviceable
parts inside. Refer servicing to a qualified technician.
10.1 Worldwide Service Service may be obtained from an authorized service
center. (Contact your local Crown/Amcron representative or our office for a
list of authorized service centers.) To obtain service, simply present the
bill of sale as proof of purchase along with the defective unit to an
authorized service center. They will handle the necessary paperwork and
repair.
Remember to transport your unit in the original factory pack.
10.2 US and Canada Service Service may be obtained in one of two ways: from an
authorized service center or from the factory. You may choose either. It is
important that you have your copy of the bill of sale as your proof of
purchase.
10.2.1 Service at a US or Canada Service Center This method usually saves the
most time and effort. Simply present your bill of sale along with the
defective unit to an authorized service center to obtain service. They will
handle the necessary paperwork and repair. Remember to transport the unit in
the original factory pack. A list of authorized service centers in your area
can be obtained from the Crown website at www.crownaudio.com, or by calling
Crown Customer Service.
Micro-Tech Series Power Amplifiers
10.2.2 Factory Service
To obtain factory service, fill out the service information page found in the
back of this manual and send it along with your proof of purchase and the
defective unit to the Crown factory.
For warranty service, we will pay for ground shipping both ways in the United
States. Contact Crown Customer Service to obtain prepaid shipping labels prior
to sending the unit. Or, if you prefer, you may prepay the cost of shipping,
and Crown will reimburse you. Send copies of the shipping receipts to Crown to
receive reimbursement.
Your repaired unit will be returned via UPS ground. Please contact us if other
arrangements are required.
10.2.3 Factory Service Shipping
Instructions:
1. Before sending a Crown product to the factory for service, first call the
Crown Service Department for a return authorization (RA) number.
2. Be sure to fill out the service information form that follows and enclose
it with your shipment, either inside the box or in a packing slip envelope
securely attached to the outside of the shipping carton. Do not send the
service information form separately. If you are sending the unit from a
Shipping Center, we recommend taping the form to the product. We also
recommend recording the serial number and model before shipping for your
reference.
3. To ensure the safe transportation of your unit to the factory, ship it in
an original factory packing container. If you don’t have the original carton,
you may obtain a product service foam-inplace shipping pack from the Crown
Factory Service Department at the number listed below. For non-warranty
service, you may also provide your own shipping pack, however we still
recommend using a Crown Supplied Shipping
Container. Minimum recommended requirements for materials are as follows: 275
P.S.I. burst test Double-Wall carton that allows for 2inch solid Styrofoam on
all six sides of unit or 3 inches of plastic bubble wrap on all six sides of
unit; securely seal the package with an adequate carton sealing tape. Do not
use light boxes or “peanuts.” Damage caused by poor packing cannot be covered
under warranty.
4. Do not ship the unit in any kind of cabinet (wood or metal). Ignoring this
warning may result in extensive damage to the unit and the cabinet.
Accessories are not needed–do not send the product documentation, cables and
other hardware.
If you have any questions, please contact Crown Factory Service.
Crown Factory Service 1718 W. Mishawaka Rd., Elkhart, Indiana 46517 U.S.A.
Telephone: 574-294-8200
800-342-6939 (North America, Puerto
Rico, and Virgin Islands only)
Facsimile: 574-294-8301 (Technical
Support) 574-294-8124 (Factory Service)
Internet: http://www.crownaudio.com
Operation Manual
Micro-Tech Series Power Amplifiers
11 Warranty
3
YEAR
UNITED STATES & CANADA
SUMMARY OF WARRANTY
Crown International, 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.
WHAT THE WARRANTOR WILL DO
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 inter-
est, 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.
Warranty work for some products can only be performed at our 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 including the return
shipment, and all taxes, duties, and other customs fees for such foreign
shipments.)
HOW TO OBTAIN WARRANTY
SERVICE
You must notify us of your need for warranty service within 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.
WARRANTY ALTERATIONS
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.
DESIGN CHANGES
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.
LEGAL REMEDIES OF PURCHASER
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 after expiration of the warranty period.
THIS STATEMENT OF WARRANTY SUPERSEDES
ANY OTHERS CONTAINED IN THIS MANUAL
FOR CROWN PRODUCTS.
12/01
Operation Manual
page 25
11 Warranty
3
YEAR
Micro-Tech Series Power Amplifiers
WORLDWIDE EXCEPT USA & CANADA
SUMMARY OF WARRANTY Crown International, 1718 West Mishawaka Road, Elkhart,
Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and ANY
SUBSEQUENT OWNER of each NEW Crown1 product, for a period of three (3) years
from the date of purchase by the original purchaser (the “warranty period”)
that the new Crown product is free of defects in materials and workmanship,
and we further warrant the new Crown product regardless of the reason for
failure, except as excluded in this 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.
WHAT THE WARRANTOR WILL DO 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.
HOW TO OBTAIN WARRANTY SERVICE You must notify your local Crown importer of
your need for warranty service within the warranty period. All components must
be shipped in the original box. 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.
WARRANTY ALTERATIONS 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.
DESIGN CHANGES 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.
LEGAL REMEDIES OF PURCHASER No action to enforce this Crown Warranty shall be commenced after expiration of the warranty period.
THIS STATEMENT OF WARRANTY SUPERSEDES
ANY OTHERS CONTAINED IN THIS MANUAL FOR
CROWN PRODUCTS.
7/01
page 26
Operation Manual
Micro-Tech Series Power Amplifiers
Crown Factory Service Information
Shipping 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: ____ Email
Model:
Serial Number:
Purchase Date :
NATURE OF PROBLEM (Be sure to describe the conditions that existed when the problem occurred and what attempts were made to correct it.)
Other equipment in system:
If warranty has expired, payment will be: ! Cash/Check ! Visa ! Master Card !
C.O.D. ! Purchase Order for Crown Dealer
Card Number:____ Exp. Date:
Signature:__
Operation Manual
ENCLOSE THIS PORTION WITH THE UNIT. DO NOT MAIL SEPARATELY.
page 27
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>