McIntosh MCC204 User Manual

MCC204 Power Amplifier

Owners
Manual

MCC204

McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903-2699 Phone: [phone] FAX: [phone]

WARNING - TO REDUCE RISK OF

FIRE OR ELECTRICAL SHOCK, DO

NOT EXPOSE THIS EQUIPMENT TO

RAIN OR MOISTURE.

IMPORTANT SAFETY INSTRUCTIONS!

PLEASE READ THEM BEFORE OPERATING THIS EQUIPMENT.

NO USER-SERVICEABLE PARTS

INSIDE. REFER SERVICING TO

QUALIFIED PERSONNEL.

To prevent the risk of electric shock, do not remove

bottom cover. No user serviceable parts inside.

General:

1. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

5. Warning: To reduce risk of fire or electrical shock,
do not expose this equipment to rain or moisture.
This unit is capable of producing high sound pres­sure levels. Continued exposure to high sound pres­sure levels can cause permanent hearing impair­ment or loss. User caution is advised and ear protec­tion is recommended when playing at high volumes.

6. Disconnect this equipment when unused for long peri­ods of time.

7. Only use attachments/accessories specified by the
manufacturer.

Installation:

8. Do not block any ventilation openings. Install in accor­dance with the manufacturers instructions.

9. Do not install near any heat sources such as radiators,
heat ducts or other equipment that produce heat.

10. Do not use this equipment near water.

11. Do not expose this equipment to dripping or splashing
and ensure that no objects filled with liquids are
placed on the equipment.

12. Do not mount this product with an unstable bracket as
the equipment may fall, causing serious injury to a
person, and serious damage to the product.

Care of Equipment:

14. Clean only with dry cloth.

15. Do not permit objects or liquids of any kind to be
pushed, spilled and/or fall into the equipment through
enclosure openings.

Repair of Equipment:

16. Refer all servicing to qualified service personnel. Ser­vicing is required when the equipment 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 equipment, the equipment has been exposed to
rain or moisture, does not operate normally, or has
been dropped.

17. Do not attempt to service beyond that described in the
operating instructions. All other service should be re­ferred to qualified service personnel.

18. When replacement parts are required, be sure the ser­vice technician has used replacement parts specified by
McIntosh or have the same characteristics as the origi­nal part. Unauthorized substitutions may result in fire,
electric shock, or other hazards.

19. Upon completion of any service or repairs to this prod­uct, ask the service technician to perform safety checks
to determine that the product is in proper operating
condition.

Connection:

13. Route DC power cords so that they are not likely to be
pinched by items placed upon or against them, paying
particular attention to the point where they enter the
instrument.

2

Thank You

Table of Contents

Your decision to own this McIntosh MCC204 Four Chan­nel Power Amplifier ranks you at the very top among dis­criminating music listeners. You now have The Best. The
McIntosh dedication to Quality, is assurance that you
will receive many years of musical enjoyment from this
unit.

Please take a short time to read the information in this
manual. We want you to be as familiar as possible with all
the features and functions of your new McIntosh.

Please Take A Moment

The serial number, purchase date and McIntosh dealer
name are important to you for possible insurance claim or
future service. The spaces below have been provided for
you to record that information:

Serial Number:

Purchase Date:

Dealer Name:

Technical Assistance

If at any time you have questions about your McIntosh
product, contact your McIntosh dealer who is familiar with
your McIntosh equipment and any other brands that may
be part of your system. If you or your dealer wish addi­tional help concerning a suspected problem, you can re­ceive technical assistance for all McIntosh products at:

McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, New York 13903
Phone: [phone]
Fax: [phone]

Customer Service

If it is determined that your McIntosh product is in need of
repair, you can return it to your dealer. You can also return
it to the McIntosh Laboratory Service Repair department.
For assistance on factory repair return procedure, contact
the McIntosh Repair Department at:

McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, New York 13903
Phone: [phone]
Fax: [phone]

Copyright 2001 ã by McIntosh Laboratory, Inc.

Safety Instructions ............................................................. 2

Thank You.......................................................................... 3

Please Take a Moment ....................................................... 3

Customer Service ............................................................... 3

Table of Contents ............................................................... 3

Introduction ....................................................................... 4

Performance Features ........................................................ 4

Dimensions ....................................................................... 5

Installation ........................................................................ 6

Side Panel Cooling and Connections ................................ 7

How to Connect for Four Channels ................................... 8

How to Connect for Three Channels ................................. 9

How to Connect for Two Channels ................................. 10

How to Connect with Subwoofer Channel ...................... 11

Top Panel Controls, Displays and Switches .................... 12

How to Operate ................................................................ 13

How to Operate in Four or Three Channel Mode ............ 14

How to Operate in Two Channel or Subwoofer Mode .... 15

How to Replace the Fuses ............................................... 16

Block Diagram ................................................................. 17

Specifications .................................................................. 18

Packing Instruction .......................................................... 19

General Notes

1. An optional McIntosh External Subwoofer Rotary Control,
Model Number R1163, is available from your McIntosh
Dealer.

2. Do not connect the Amplifiers Speaker Negative Terminal
Connection directly to the Vehicle Chassis. Failure to observe
this could result in damage to your Amplifier.

3. It is advisable to place an inline fuse as close as possible to
the battery.

4. For additional connection information, refer to the owner s
manual(s) for any component(s) connected to the MCC204
Amplifier.

5. There is a built-in turn on delay which will mute the speaker
outputs for approximately two seconds when the amplifier is
turned on.

6. It is very important that loudspeaker cables of adequate size
be used in your music system, to ensure that there will be no
power loss or heating. If your loudspeaker cables are 25 feet
(7.62m) or less, use at least 16 Gauge wire size or larger.

7. The MCC204 Line Level OUTPUTs are wired as a Y
connection with the INPUTs to pass the input signals on to
additional amplifiers (keep cable lengths as short as
possible). The McIntosh MX406 Control Center is capable of
driving several additional
power amplifiers with no
degradation of the signal.

8. The MCC204 can accept
speaker level inputs at its Input
Jacks. Refer to the diagram for
connection.

(-) NEGATIVE SPEAKER OUTPUT

(+) POSITIVE SPEAKER OUTPUT

3

Introduction

Now you can take advantage of traditional McIntosh stan­dards of excellence in the MCC204 Power Amplifier. Four
50 watt high current output channels will drive any high
quality loudspeaker system to its ultimate performance.
The MCC204 reproduction is sonically transparent and ab­solutely accurate. The McIntosh Sound is The Sound of
the Music Itself.

Performance Features

· Power Output

The MCC204 consists of four separate power amplifier
channels, each capable of 50 watts into 4 ohm speakers
with less than 0.005% distortion.

· Four Bridgeable Channels

The MCC204 includes four 50 watt amplifier channels.
Each pair of channels can be set in bridged configuration
for 200 watts output into 4 ohm loudspeakers with less
than 0.01% distortion.

· High Current Output

A peak output current of 15 amperes ensures that the
MCC204 will successfully drive high quality loudspeakers,
such as McIntosh, for a truly exciting sound experience.

· Equalizer and Variable Crossover Filters

The one band equalizer has a center frequency that is vari­able from 40 Hz to 2,000 Hz which can be either cut or
boosted ±12db. 12dB per octave high pass filters with vari­able corner frequencies from 50Hz to 120Hz and 12dB per
octave low pass filters with variable corner frequencies
from 50Hz to 120Hz.

· Power Guard and Sentry Monitor

All channels include the patented McIntosh Power Guard
circuit that prevents the amplifier from being overdriven
into clipping with its harsh distorted sound that can also
damage your valuable loudspeakers. McIntosh Sentry
Monitor power output stage protection circuits are present
on all channels to ensure the MCC204 will have a long and
trouble free operating life.

· Thermal Protection with Multi-Speed Cooling Fan

Built-in thermal protection circuits guard against overheat­ing which could shorten the normal long life expectancy of
your McIntosh Power Amplifier. Cooling fan speed is con­trolled by temperature sensors attached to the interior of
the extruded aluminum cooling tunnel. The fan is normally
off. When needed, the fan will automatically switch on,
and speed is increased as needed for additional cooling.

· Fully Discrete Design

The MCC204 has a fully complimentary double balanced
amplifier design and is identical to that found in
McIntoshs leading home amplifiers.

· Balanced Inputs with Pass Through

The Balanced Inputs cancel out interference noise that is
produced by other sources in the vehicle and can be di­rectly connected to the bridged speaker output of any head
unit. The MCC204 provides four line level outputs, for the
convenience of connecting multi-amplifier systems.

· Remote Subwoofer Control and Line Output

The subwoofer level can be controlled via an external ro­tary control, which can be remotely mounted in the vehicle.
A line level summed output is provided to drive an external
subwoofer power amplifier. The inputs to both channels are
summed for this output.

· Gold Plated Terminals

McIntosh provides gold plated input and output terminals
on the amplifiers for superior corrosion resistance. It is a
very important feature in the automotive environment.
Speaker wires to 10 AWG and DC input wires to 4 AWG
can be accommodated.

· Speaker Protection

If for any reason, a DC (Direct Current) voltage appears at
the speaker output terminals, a built-in circuit turns off the
amplifier power supplies to prevent damage to your valu­able loudspeakers.

4

Dimensions

The following dimensions can assist in determining the
best location for your MCC204. There is additional infor­mation on the next page pertaining to installing the
MCC204 into your vehicle.

Top View of the MCC204

13-

21/32

34.69cm

11.00"

27.94cm

2-

11/16

"

6.82cm

Dimensions

"

Side View of the MCC204

11"

27.93cm

11-

7/8

30.16cm

"

12-

1/2

31.75cm

"

11/32

"

10.93cm

2-

15/16

7.49cm

"

5

Installation

It is recommended that a professional who is skilled in all
aspects of installation and operation install the MCC204
and any associated mobile audio equipment.

Amplifier Ventilation

Always provide adequate ventilation for the MCC204. The
amplifier requires an adequate airflow into the cooling fan,
which is located on the left side of the amplifier. The warm
air exits the amplifier through vents on the heatsinks. See
figure 1. Be sure to provide at least 1-1/2 inches clearance
in front of the cooling fan and 1 inch clearance at the sides
of the heatsinks.

The cooling fan is controlled by temperature sensors,
attached to the interior of the tunnel. The fan is normally
off. If the program material contains sustained loud pas­sages demanding high power, the fan will turn-on to in­crease cooling. If cooling is still not sufficient, additional
heating will shut down the amplifiers internal power sup­ply completely and the Power Guard LEDs will light. The
fan will continue to run and once normal temperatures are
restored, operation will resume.

The amplifier can be mounted vertically or horizontally
and may be located under a seat if adequate clearance is
available. The preferred installation method is to mount the
amplifier directly to the vehicle frame using the hardware
supplied with the amplifier.

It is not recommended that the amplifier be mounted
under the hood or in a location where it will be directly ex­posed to the elements. The openings in the fan housing and
heat tunnel vents can allow internal components to be dam­aged by exposure to water, chemicals or any form of road
dust or debris.

Installation

WarmAir

Figure 1

Cool Air

WarmAir

Remove Top Cover Screws

Figure 2

Remove Top Cover Screws

Removing the Glass Panel

To access the MCC204 Controls, remove the glass panel
by removing the four hex bolts with the supplied 3/32 hex
key. See figure 2. Attach the supplied suction cup to the top
center of the glass panel and carefully raise it high enough
to put your hand under. Temporarily place the removed
glass panel in a safe place, remove the suction cup and
save it for future use.

Removing the End Caps

To access the MCC204 Connecting Terminal Blocks, re­move the Glass Panel first (the above step) and then re­move the Phillips Screws holding the End Caps on both
sides of the amplifier and lift the end caps off. See figure 3.

6

Remove End Cap Screws

Figure 3

Remove End Cap Screws

Side Panel Cooling and Connections

Connect to the Negative (-)
vehicle battery terminal

SUBWOOFER OUTPUTS
supply a four channel
summed output

Connect to the positve (+)
vehicle battery terminal
with an inline fuse

OUTPUTs from the
INPUT Signal Source
to connect to another
Power Amplifier

Cooling Fan
Air Intake

Receives the Amplifier
Turn-ON signal from a
McIntosh Control Center

OUTPUT Connections
for loudspeakers

Connector for optional
SUBwoofer REMOTE
Volume CONTROL

INPUTs for
audio cables
from a signal
source

OUTPUT Connections
for loudspeakers

Controls the Power Guard
Circuit when connected to
certain McIntosh Control
Centers

7

How to Connect for Four Channels

How to Connect for Four Channels

1. Connect a wire from the Control Center Amp On to the
MCC204 ON Connector on the right side of the ampli­fier.

Note: All cables should be connected to the amplifier

before connecting the DC power cables to the
battery.

2. Connect a wire from a McIntosh Control Center with
Power Guard to the MCC204 PG Connector on the
right side of the amplifier.

3. Connect cables (up to 12AWG) from four separate
loudspeakers, to the Amplifiers Channels 1, 2, 3 and 4
OUTPUT Terminals, being careful to observe the cor­rect polarities.

4. Connect audio cables from the Control Center Outputs
to the MCC204 Inputs 1, 2, 3 and 4.

5. Optional Connection illustrated below shows the SUB
OUTput connected to a separate Subwoofer Power
Amplifier and Subwoofer Loudspeaker.

McIntosh Control Center

Left Rear

Right Rear

Note: The Subwoofer Output Signal is at line-level,

summed from all the Input Channels and is
available regardless of the MCC204 Operating
Mode used. The Subwoofer Output Level can be
remotely controlled by the optional McIntosh
External Subwoofer Rotary Control connected to
the SUB REMOTE CONTROL jack on the
MCC204.

6. Connect the MCC204 to the vehicle battery terminals
using size 4AWG (maximum) cables.

Note: It is advisable to place an inline fuse of a suitable

size as close as possible to the battery.

Subwoofer
Loudspeaker

Optional Subwoofer Amplifier

Left Front
Loudspeakers

Right Front
Loudspeakers

Left Front

Right Front

McIntosh External
Subwoofer Rotary Control

Power Guard

Amp ON

-

Vehicle
Battery

Right Rear
Loudspeakers

Left Rear
Loudspeakers

+

Fuse

8

How to Connect for Three Channels

How to Connect for Three Channels

1. Connect a wire from the Control Center Amp On to the
MCC204 ON connector on the right side of the ampli­fier.

Note: All cables should be connected to the amplifier

before connecting the DC power cables to the
battery.

2. Connect a wire from a McIntosh Control Center with
Power Guard to the MCC204 PG connector on the
right side of the amplifier.

3. Connect speaker cables (up to 12AWG) from a tweeter
to the Amplifiers Channel 1 OUTPUT Terminals be­ing careful to observe the correct polarities.

4. Connect speaker cables from a mid-range loudspeaker
to the Amplifiers Channel 2 OUTPUT Terminals, be­ing careful to observe the correct polarities.

Note: The connecting information shown here is for a

single channel of an audio system. For the other
channel, connect a second MCC204 and
loudspeakers in a similar manner.

McIntosh Control Center

Left Output

5. Connect speaker cables from one woofer to the
Amplifiers Channels 3 and 4 BRIDGED OUTPUT
Terminals, being careful to observe the correct polari­ties.

6. Connect an audio cable from one of the control center
outputs to the input of an external crossover.

7. Connect an audio cable from the external crossover
TWEETER output to the MCC204 Channel 1 Input.

8. Connect an audio cable from the external crossover
MID-RANGE output to the MCC204 Channel 2 Input.

9. Connect an audio cable from the external crossover
WOOFER output to the MCC204 Channel 3 Input.

Note: Do not connect a cable to the MCC204 Channel 4

Input.

10. Connect the MCC204 to the vehicle battery terminals
using size 4AWG (maximum) cables.

Note: It is advisable to place an inline fuse of a suitable

size as close as possible to the battery.

McIntosh Electronic Crossover

Tweeter
Loudspeaker

Midrange
Loudspeaker

Power Guard

Amp ON

-

Vehicle
Battery

Woofer
Loudspeaker

+

Fuse

9

How to Connect for Two Channels

How to Connect for Two Channels

1. Connect a wire from the Control Center Amp On to
the MCC204 ON Connector on the right side of the
amplifier.

Note: All cables should be connected to the amplifier

before connecting the DC power cables to the
battery.

2. Connect a wire from a McIntosh Control Center with
Power Guard to the MCC204 PG Connector on the
right side of the amplifier.

3. Connect cables (up to 12AWG) from two separate
loudspeakers, one to the Amplifier Bridged Channels 1
and 2 OUTPUT Terminals, and one to Bridged Chan­nels 3 and 4 OUTPUT Terminals, being careful to ob­serve the correct polarities.

4. Connect audio cables from the Control Center Outputs
to the MCC204 Inputs 1 and 3.

5. Optional Connection illustrated below shows the SUB
OUTput connected to a separate Subwoofer Power
Amplifier and Subwoofer Loudspeaker.

McIntosh Control Center

Left Rear

Right Rear

Note: The Subwoofer Output Signal is at line-level,

summed from all the Input Channels and is
available regardless of the MCC204 Operating
Mode used. The Subwoofer Output Level can be
remotely controlled by the optional McIntosh
External Subwoofer Rotary Control connected to
the SUB REMOTE CONTROL jack on the
MCC204.

6. Connect the MCC204 to the vehicle battery terminals
using size 4AWG (Maximum) cables.

Note: It is advisable to place an inline fuse of a suitable

size as close as possible to the battery.

Optional connections for
controlling the Subwoofer
Level by using the Front to
Rear Fader Control on the
Control Center

Optional Subwoofer Amplifier

Subwoofer
Loudspeaker

Left Loudspeakers

Left Front

Right Front

McIntosh External
Subwoofer Rotary Control

Power Guard
Amp ON

Vehicle
Battery

Right Loudspeakers

+-

Fuse

10

How to Connect with Subwoofer Channel

How to Connect with Subwoofer Channel

1. Connect a wire from the Control Center Amp On to
the MCC204 ON Connector on the right side of the
amplifier.

Note: All cables should be connected to the amplifier

before connecting the DC power cables to the
battery.

2. Connect a wire from a McIntosh Control Center with
Power Guard to the MCC204 PG Connector on the
right side of the amplifier.

3. Connect cables (up to 12AWG) from two separate up­per range loudspeakers, to the Amplifiers Channels 1
and 2 OUTPUT Terminals, and subwoofer loud­speaker to Channels 3 and 4 BRIDGED OUTPUT Ter­minals, being careful to observe the correct polarities.

4. Connect audio cables from the Control Center Outputs
to the MCC204 Inputs 1 and 2.

McIntosh Control Center

Note: The Subwoofer Output Signal is at line-level,

summed from all the Input Channels and is
available regardless of the MCC204 Operating
Mode used. The Subwoofer Output Level can be
remotely controlled by the optional McIntosh
External Subwoofer Rotary Control connected to
the SUB REMOTE CONTROL jack on the
MCC204.

5. Connect the MCC204 to the vehicle battery terminals
using size 4AWG (Maximum) cables.

Note: It is advisable to place an inline fuse of a suitable

size as close as possible to the battery.

Optional connections for
controlling the Subwoofer
Level by using the Front to
Rear Fader Control on the
Control Center

Left Loudspeakers

Right Loudspeakers

Left Rear
Right Rear

Left Front

Right Front

McIntosh External
Subwoofer Rotary Control

Power Guard
Amp ON

-

Vehicle
Battery

Subwoofer
Loudspeaker

+

Fuse

11

Top Panel Controls, Display and Switches

CROSSOVER Filter
Switch and Control se­lect the low roll-off fre­quency, high roll-off
frequency or flat fre­quency response

POWER
GUARD LED
lights when the
Power Guard
Circuit acti­vates for Am­plifier Channels
1 or 2

CH 3-4 MODE Switch
selects STEREO or
BRIDGE mode of
operation

CH 3-4 EQUALIZER Con­trols select the Frequency and
the Level of Boost or Cut at
the Center Frequencies

CH 3-4 SENSITIVITY
Individual Input Sensi­tivity Controls for
Channels 3 and 4

POWER GUARD LED
lights when the Power
Guard Circuit activates
for Amplifier Channels
3 or 4

INPUT
SOURCE
Switch for
Channels 3, 4
selects either
CHs 1, 2, or
3, 4 or
Subwoofer
(Sum of CHs
1, 2, 3, and 4)

12

CROSSOVER Filter
Switch and Control se­lect the low roll-off fre­quency, high roll-off
frequency or flat fre­quency response

CH 1-2 MODE Switch
selects STEREO or
BRIDGE mode of
operation

CH 1-2 EQUALIZER Con­trols select the Frequency and
the Level of Boost or Cut at
the center frequencies

CH 1-2 SENSITIVITY
Individual Input Sensitivity
Controls for Channels 1
and 2

Introduction

How to Operate

The McIntosh MCC204 is a highly versatile amplifier that
can be configured in many ways. This manual gives ex­amples of some of the most common configurations. The
best way to set equalization and filter controls is through
the use of a real-time spectrum analyzer and the expertise
of a professional installer. This manual will guide you
through the basic operation, however we suggest you refer
to your dealer for further information on the use of this
unit. To access the Amplifier Controls and Switches refer
to Removing the Glass Panel located on page 6 of this
Owners Manual.

Crossover

The CROSSOVER Switch OUT Position selects a Flat Fre­quency Response. When the CROSSOVER Switch is in
the LP (low frequency pass) Po­sition, the Amplifier will pass all
frequencies below the setting of
the CROSSOVER FRE­QUENCY Control. If the
CROSSOVER Switch is in the
HP (high frequency pass) Posi-

Figure 4

tion, the Amplifier will pass all
frequencies above the setting of the CROSSOVER FRE­QUENCY Control. Refer to figure 4.

Input Sensitivity Controls

The SENSITIVITY controls allows the setting of the input
sensitivity, of all four amplifier channels, to provide an
ideal match for the signal source be­ing used. The most desirable setting
allows the control center to have a
useful volume range as wide as pos­sible from loud to soft. A good place
to start is to set the amplifiers SEN­SITIVITY Control to the output volt-

Figure 6

age called out in your control center
owners manual. The Level controls can be set for any sen­sitivity from .5 volts to 8 volts.
Refer to figure 6.

Note: When used in conjunction with a McIntosh Control

Center, you may find setting the Sensitivity controls to
the center detent (1.5V) works best.

Equalizer

Each of the two pairs of channels (1 and 2, 3 and 4) is
equipped with an equalizer. The equalizer is not intended to
act as a tone control. The one-band equalizer is best uti­lized as a notch filter to reduce a
peak (as located by real-time analy­sis with an RTA) in your systems
frequency response. If you are at­tempting to equalize a system with­out RTA data, play music you are

Figure 5

familiar with, set the equalizer
LEVEL Control to +12 and slowly turn the FREQUENCY
Control to get an idea where in the musical spectrum the
frequency numbers are located. Then set the LEVEL Con­trol back to 0 and listen to the system to determine its
equalization needs. Subtle adjustments are best and cutting
usually sounds better than boosting. Refer to figure 5.

13

How to Operate in Four or Three Channel Mode

How to Operate Four Channel Mode How to Operate Three Channel Mode

In the Four Channel Mode, all channels operate as inde­pendent 50 watt amplifiers. A typical four channel applica­tion is to drive a pair of full range loudspeakers in the front
section of a vehicle and a second pair in the rear. Refer to
figures 7 and 8.

Power

The MCC204 will turn On or Off when the Control Center
turns On or Off.

Note: There must be an Amp ON connection between the

MCC204 and the signal source unit in order for the
amplifier power turn On and Off to function.

Input Source

Set the Input SOURCE Switch to the 3, 4 position for 4
Channel Mode.

Sensitivity Controls

The Sensitivity Controls allow setting of the input level of
all four amplifier channels to provide an ideal match for the
signal source being used.

Mode

Set both MODE Switches to the STereo position to config­ure the amplifier for four channel operation.

Crossover

Set the CROSSOVER Switches to the OUT position since
all channels are operating at full frequency range.

In the Three Channel, Tri-amp Mode, channel 1 operates as
a 50 watt amplifier for the tweeter, channel 2 operates as a
50 watt amplifier for the mid-range and bridged channels 3
and 4 operate as a 200 watt amplifier driving a woofer. Re­fer to figures 7 and 8.

Power

The MCC204 will turn On or Off when the control center
turns On or Off.

Note: There must be an Amp ON connection between the

MCC204 and the signal source in order for the
amplifier turn On and Off to function.

Input Source

Set the Input SOURCE Switch to 3, 4.

Sensitivity Controls

The Sensitivity Controls allow setting the input level of
amplifier channels 1, 2 and 3 to provide an ideal match for
the signal source being used. Sensitivity Control 3 adjusts
the woofer level balance and Sensitivity Control 4 has no
effect.

Mode

Set the Channels 1-2 MODE Switch to the STereo position.
Set the Channels 3-4 output MODE Switch to the BRidged
position.

Crossover

Set the CROSSOVER Switches to the OUT position since
all channels are operating at full frequency range.

14

Figure 7

Figure 8

How to Operate in Two Channel or Subwoofer Mode

How to Operate in Two Channel Mode How to Operate in Subwoofer Mode

In the Two Channel Mode, Channels 1 and 2, and Channels
3 and 4 operate in bridged configuration as a pair of full
frequency range 200 watt amplifiers. A typical application
is use of a more powerful amplifier for stereo reproduction.
Refer to figures 7 and 8.

Power

The MCC204 will turn On or Off when the Control Center
turns On or Off.

Note: There must be an Amp ON connection between the

MCC204 and the signal source unit in order for the
amplifier power turn On and Off to function.

Input Source

Set the Channel 3-4 SOURCE Switch to 3, 4.

Sensitivity Controls

The Sensitivity Controls 1 and 3 allow the setting of input
level of both bridged pairs of amplifier channels to provide
an ideal match for the signal source being used.

Mode

Set both the Channel 1-2 MODE Switch and the Channel
3-4 MODE Switch to the BRidged position to configure
the amplifier for two channel operation.

Crossover

Set the CROSSOVER Switches to the OUT position since
both bridged channels are operating at full frequency
range.

In the Sub Woofer Mode, Channels 1 and 2 operate as in­dependent 50 watt amplifiers, driving two midrange and
high frequency or full range speakers. Channels 3 and 4
operate in Bridged Mode as a single 200-watt amplifier,
driving a low frequency speaker. A typical Subwoofer Ap­plication is to drive two upper-range loudspeakers and one
woofer or subwoofer. Refer to figures 7 and 8.
.

Power

The MCC204 will turn On or Off when the Control Center
turns On or Off.

Note: There must be an Amp ON connection between the

MCC204 and the signal source unit in order for the
amplifier power turn On and Off to function.

Input Source

Set the Channel 3-4 SOURCE Switch to the 1-4 (SUB) po­sition to send the summed signals from Input 1 and 2 to the
Bridged Channels 3 and 4 for low-pass filtering.

Sensitivity Controls

The Sensitivity Controls allow setting the input level of
Amplifier Channels 1, 2 and 3 to provide an ideal match
for the signal source being used. Sensitivity Control 3 ad­justs the subwoofer level balance and Sensitivity Control 4
has no effect.

Output Mode

Set the Channels 1-2 MODE Switch to the STereo position
and the Channels 3-4 MODE Switch to the BRidged posi­tion to operate in the Subwoofer Mode.

Crossover

Set the Channel 1-2 CROSSOVER Switch to the HP Posi­tion and the Channel 3-4 CROSSOVER Switch to the LP
Position. Adjust the CROSSOVER FREQUENCY Control
for both Channels 1-2 and 3-4 to the same frequency set­ting. The selection of the Crossover Frequency should be
determined by the recommendations of the Loudspeaker
Manufacturer for the best performance.

15

Remove Top Cover Screws

Remove Top Cover Screws

Figure 9

Remove Three Screws

Figure 10

Remove Three Screws

Figure 11

Location of the two fuses

How to Replace the Fuses

If the MCC204 produces no sound, there is no Illumination
of the Nomenclature on the Top Glass Panel, and the power
connections seem secure, one or more of the Amplifiers
Fuse(s) may have failed. Under normal operating
conditions your amplifiers fuses should not fail. Failure of
a fuse is usually an indication of a problem. Replacing the
fuse, if there is a problem in the amplifier, may incur a risk
of further damage. Refer to figures 9, 10 and 11.

Caution: Disconnect the Amplifier from the Vehicle Battery

1. Before accessing fuses, disconnect both the positive
and negative power cables from the DC input
terminals on the left side of the amplifier using a
5/32 hex key.

2. Remove the Top Glass Panel by first removing the
four hex bolts with the supplied 3/32 hex key.

3. To remove the Top Glass Panel, attach the supplied
suction cup to the top center of the glass panel and
carefully raise it high enough to put your hand under.
Temporarily place the removed glass panel in a safe
place, remove the suction cup and save it for future
use.

4. Remove the Phillips Screws holding the End Caps on
both sides of the amplifier and lift the end caps off.

5. Remove the two Phillips Screws located between the
row of Controls/Switches and the Top/Bottom edge
of the Gold Faceplate Control Panel.

6. Remove all 10 crossover, equalizer and sensitivity
knobs.

7. Remove the Gold Faceplate Control Panel.

8. Remove the fuses with needle nose pliers, taking care
to avoid hitting parts on the ciruit board.

9. Replace the fuse with one of the same type and
rating, as unauthorized substitutions may prove
hazardous to you and the amplifier.

10. When reinserting the fuse, set it in place with the

11. Re-install the Gold Faceplate Control Panel and all

12. Re-connect the power cables to the vehicle battery.
If the replacement fuse(s) fails again, have the amplifier
repaired at a McIntosh Service Center.

(or DC Power Supply) as Potentially Dangerous
Currents exist inside the amplifier.

Note: To determine if the fuse has failed, examine the

link between the two fuse legs to see if it has a
break in it.

pliers, then push it the rest of the way in with your
finger to avoid having the pliers slip and hit the
circuit board.

10 crossover, equalizer and sensitivity knobs.

How to Replace the Fuses

16

MCC204 Block Diagram

17

Block Diagram

Specifications

Specifications

Power Output Per Channel

50 watts into 4 ohm loads and 100 watts into 2 ohm loads
is the minimum sine wave continuous average power out­put per channel all four channels operating.

Power Output Bridged

200 watts into 4 ohm loads is the minimum sine wave con­tinuous average power output.

Rated Power Band

20Hz to 20,000Hz

Total Harmonic Distortion

Maximum Total Harmonic Distortion at any power
level from 250 milliwatts to rated power output is:

0.005% for 4 ohm loads

0.01% for 2 ohm loads

0.01% for Bridged Mode with 4 ohm loads

Dymanic Headroom

1dB

Frequency Response

+0, -0.25dB from 20Hz to 20,000Hz
+0, -3dB from 10Hz to 100,000Hz

Intermodulation Distortion

Maximum Intermodulation Distortion if instanta­neous peak output per channel does not exceed
twice the rated output, for any combination of fre­quencies from 20Hz to 20,000Hz, with all channels
operating is:

0.005% for 4 ohm loads

0.01% for 2 ohm loads

0.01% for Bridged Mode with 4 ohm loads

Input Impedance

12,000 ohms

Power Requirements

12 Volts DC, 2.5 amps (idle) - 38 amps (50 watts)

Dimensions

12.5 inches (31.8cm) wide, 3.0 inches (7.6cm)
high, 13.7 inches (34.8cm) depth

Weight

14.5 pounds (6.6Kg) net, 17.0 pounds (7.7Kg) in
shipping carton

Sensitivity

0.5 Volts

A-Weighted Signal To Noise Ratio

105dB (1.5V)

One Band Equalizer

Center Frequency is variable from 40Hz to 2,000Hz, level
variable ±12db, Q fixed at 2

Crossover

Selectable High pass or Low pass. The frequency is vari­able from 50Hz to 120Hz. The slope is 12dB per octave
(Low pass is 24dB per octave in bridged mode)

Subwoofer Output

Low Pass filtered at 200Hz with a 6db per octave slope
(level variable ±12db when using optional McIntosh Exter­nal Subwoofer Rotary Control)

18

Packing Instructions

Packing Instructions

In the event it is necessary to repack the equipment for
shipment, the equipment must be packed exactly as shown
below, failure to do so will result in shipping damage.
Make sure that the Top Glass Panel is firmly secured to the
chassis using the supplied hex head screws.

Use the original shipping carton and interior parts only
if they are all in good serviceable condition. If a shipping
carton or any of the interior part(s) are needed, please call
or write Customer Service Department of McIntosh Labo­ratory. Please see the Part List for the correct part numbers.

Quantity Part Number Description

1 034162 Shipping carton only
2 034132 End cap (Foam pad)

19

McIntosh Laboratory, Inc.

2 Chambers Street

Binghamton, NY 13903

McIntosh Part No. 040765