Owner’s
Manual
MCC302 Power Amplifier
MCC302
McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903-2699 Phone: 607-723-3512 FAX: 607-724-0549
Thank You
Table of Contents
Your decision to own this McIntosh MCC302 Two Channel Safety Instructions ............................................................. 2
Power Amplifier ranks you at the very top among discrimi-
nating 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.
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 Two Channels ................................... 8
How to Connect with Subwoofer Channel ........................ 9
Top Panel Controls, Displays and Switches .................... 10
How to Operate................................................................ 11
How to Replace the Fuses ............................................... 12
Block Diagram................................................................. 13
Specifications .................................................................. 14
Packing Instruction .......................................................... 15
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:
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 MCC302
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 MCC302 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.
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 addi-
tional help concerning a suspected problem, you can re-
ceive technical assistance for all McIntosh products at:
McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, New York 13903
Phone: 607-723-1545
Fax: 607-723-3636
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:
8. The MCC302 can accept speaker level inputs at its Input
McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, New York 13903
Phone: 607-723-3515
Fax: 607-723-1917
Jacks. Refer to the diagram for
(-) NEGATIVE SPEAKER OUTPUT
connection.
(+) POSITIVE SPEAKER OUTPUT
Copyright 2001 ã by McIntosh Laboratory, Inc.
3
Introduction
Now you can take advantage of traditional McIntosh stan-
dards of excellence in the MCC302 Power Amplifier. Two
150 watt high current output channels will drive any high
quality loudspeaker system to its ultimate performance.
The MCC302 reproduction is sonically transparent and ab-
solutely accurate. The McIntosh Sound is “The Sound of
the Music Itself.”
· Thermal Protection with Multi-Speed Cooling Fans
Built-in thermal protection circuits guard against overheat-
ing which could shorten the normal long life expectancy of
your McIntosh Power Amplifier. Cooling fan speed is con-
trolled by temperature sensors attached to the interior of
the extruded aluminum cooling tunnel. The fans are nor-
mally off. When needed, the fans will automatically switch
on, and speed is increased as needed for additional cooling.
Performance Features
· Fully Discrete Design
· Power Output
The MCC302 has a fully complimentary double balanced
amplifier design and is identical to that found in
McIntosh’s leading home amplifiers.
The MCC302 consists of two separate power amplifier
channels, each capable of 150 watts into 4 ohm speakers
with less than 0.005% distortion.
· Balanced Inputs with Pass Through
· Bridgeable Channels
The Balanced Inputs cancel out interference noise that is
produced by other sources in the vehicle and can be di-
rectly connected to the bridged speaker output of any head
unit. The MCC302 provides two line level outputs, for the
convenience of connecting multi-amplifier systems.
The MCC302 includes two 150 watt amplifier channels.
Both channels can be set in bridged configuration for 600
watts output into a 4 ohm loudspeaker with less than
0.008% distortion.
· High Current Output
· Remote Subwoofer Control and Line Output
The subwoofer level can be controlled via an external ro-
tary 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.
A peak output current of 30 amperes ensures that the
MCC302 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 vari-
able from 40 Hz to 2,000 Hz which can be either cut or
boosted ±12db. 12dB per octave high pass filters with vari-
able corner frequencies from 50Hz to 120Hz and 12dB per
octave low pass filters with variable corner frequencies
from 50Hz to 120Hz.
· 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.
· 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 MCC302 will have a long and
trouble free operating life.
· 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 valu-
able loudspeakers.
4
Dimensions
Dimensions
The following dimensions can assist in determining the
best location for your MCC302. There is additional infor-
mation on the next page pertaining to installing the
MCC302 into your vehicle.
Top View of the MCC302
13-21/32"
34.69cm
11.00"
27.94cm
2-11/16"
6.82cm
12-1/2"
31.75cm
11-7/8"
30.16cm
Side View of the MCC302
11"
27.93cm
11/32"
10.93cm
2-15/16"
7.49cm
5
Installation
Installation
It is recommended that a professional who is skilled in all
aspects of installation and operation install the MCC302
and any associated mobile audio equipment.
Amplifier Ventilation
Always provide adequate ventilation for the MCC302. The
amplifier requires an adequate airflow into the cooling
fans, which are 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 clear-
ance in front of the cooling fans and 1 inch clearance at the
sides of the heatsinks.
The cooling fans are controlled by temperature sensors,
attached to the interior of the tunnel. The fans are normally
off. If the program material contains sustained loud pas-
sages demanding high power, the fans will turn-on to in-
crease cooling. If cooling is still not sufficient, additional
heating will shut down the amplifier’s internal power sup-
ply completely and the Power Guard LEDs will light. The
fans 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 ex-
posed to the elements. The openings in the fan housings
and heat tunnel vents can allow internal components to be
damaged by exposure to water, chemicals or any form of
road dust or debris.
Removing the Glass Panel
To access the MCC302 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 MCC302 Connecting Terminal Blocks, re-
move the Glass Panel first (the above step) and then re-
move the Phillips Screws holding the End Caps on both
sides of the amplifier and lift the end caps off. See figure 3.
6
Side Panel Cooling and Connections
Connect to the Negative (-)
vehicle battery terminal
Connect to the positve (+)
vehicle battery terminal
with an inline fuse
Cooling Fan
Air Intake
Cooling Fan
Air Intake
SUBWOOFER OUTPUTS
supply a two channel
summed output
Receives the Amplifier
Turn-ON signal from a
McIntosh Control Center
OUTPUTs from the
INPUT Signal Source
to connect to another
Power Amplifier
INPUTs for
audio cables
from a signal
source
OUTPUT Connections
for loudspeakers
Connector for optional
Controls the Power Guard
SUBwoofer REMOTE
Volume CONTROL
Circuit when connected to
certain McIntosh Control
Centers
7
How to Connect for Two Channels
How to Connect for Two Channels
Note: The Subwoofer Outputs are line-level outputs and
summed from all the Input Channels. They can be
remotely controlled by connecting a cable from the
SUB REMOTE CONTROL jack to the Optional
External Rotary Control.
1. Connect a wire from the Control Center Amp On to
the MCC302 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.
6. Optional Connection allows the SUB REMOTE CON-
TROL to be connected to the Power Amplifier, regard-
less of the MCC302 Operating Mode used.
7. Connect the MCC302 to the vehicle battery terminals
using size 4AWG (Maximum) cables.
2. Connect a wire from a McIntosh Control Center with
Power Guard to the MCC302 PG Connector on the
right side of the amplifier.
3. Connect cables (up to 12AWG) from two separate
loudspeaker systems, to the Amplifier’s Channels 1
and 2 OUTPUT Terminals, being careful to observe
the correct polarities.
Note: It is advisable to place an inline fuse of a suitable
size as close as possible to the battery.
4. Connect audio cables from the Control Center Outputs
to the MCC302 Inputs 1 and 2.
5. Optional Connection illustrated below shows the SUB
OUTput connected to a separate Subwoofer Power
Amplifier and Subwoofer Loudspeaker.
Subwoofer
Loudspeaker
McIntosh Control Center
Optional Subwoofer Amplifier
Power Guard
Amp ON
Left Front
Right Front
McIntosh External
Subwoofer Rotary Control
Left Loudspeakers
Right Loudspeakers
-
+
Vehicle
Battery
Fuse
8
How to Connect for Bridged Subwoofer Mode
How to Connect for Bridged Subwoofer Mode
There are many different possible Vehicle Audio System
combinations utilizing the MCC302 Power Amplifier. It is
recommended that a professional who is skilled in all as-
pects of Vehicle Audio Systems assist you in the selection
and installation. The illustration below is just one of the
many possible combinations.
1. Connect a wire from the Control Center Amp On to the
MCC302 ON Connector on the right side of the ampli-
fier.
OUTPUT Terminals, being careful to observe the cor-
rect polarities.
4. Connect audio cables from the Control Center Outputs
to the McIntosh Power Amplifier (Upper Range) Inputs
1 and 2.
5. Connect audio cables from the McIntosh Power Ampli-
fier (Upper Range) Outputs 1 and 2 to the MCC302,
Inputs 1 and 2.
Note: The Subwoofer Output is summed from both of the
Input Channels and can be remotely controlled by
connecting a cable from the SUB REMOTE
CONTROL jack to the Optional External Rotary
Control.
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 MCC302 PG Connector on the
right side of the amplifier.
3. Connect cables (up to 12AWG) from four separate
loudspeakers connected in a series/parallel combina-
tion, to the Amplifier’s Channels 1 and 2 BRIDGE
6. Connect the MCC302 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 Control Center
McIntosh Power Amplifier (Upper Range)
Power Guard
Amp ON
Left Front
Right Front
McIntosh External
Subwoofer Rotary Control
(+)
(+)
(-)
(-)
-
+
Vehicle
Battery
Fuse
(+)
(+)
(-)
(-)
9
Top Panel Controls, Display and Switches
EQUALIZER Controls select
CROSSOVER Filter
SOURCE Switch selects either
CHs 1, 2, or 1 - 2 SUBwoofer
(Sum of CHs 1, 2)
the Frequency and the Level
of Boost or Cut at the Center
Frequencies for Channels 1
and 2
Switch and Control select
the low roll-off frequency,
high roll-off frequency or
flat frequency response
MODE Switch selects
STEREO or BRIDGE
mode of operation
POWER GUARD
LED lights when the
Power Guard Circuit
activates for Ampli-
fier Channels 1 or 2
SENSITIVITY
Individual Input Sensi-
tivity Controls for
Channels 1 and 2
10
How to Operate
Introduction
Input Sensitivity Controls
The McIntosh MCC302 is a highly versatile amplifier that
can be configured in many ways. This manual gives ex-
amples 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.
The SENSITIVITY controls allows the setting of the input
sensitivity, of both 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
Figure 6
SENSITIVITY Control to the output
voltage called out in your control center owner’s manual.
The Level controls can be set for any sensitivity from .5
volts to 8 volts.
Power
Refer to figure 6.
The MCC302 will turn On or Off when the Control Center
Note: In BRIDGE MODE Sensitivity Control 2 has no effect.
When used in conjunction with a McIntosh Control
Center, you may find setting the Sensitivity controls to
the center detent (1.5V) works best.
turns On or Off.
Note: There must be an Amp ON connection between the
MCC302 and the signal source unit in order for the
amplifier power turn On and Off to function.
Operating in Two Channel Mode
Crossover
Input Source
Set the Input SOURCE Switch to the 1, 2
position. Refer to figure 7.
The CROSSOVER Switch OUT Position selects a Flat Fre-
quency Response. When the CROSSOVER Switch is in
the LP (low frequency pass) Posi-
tion, the Amplifier will pass all
frequencies below the setting of
the CROSSOVER FREQUENCY
Control. If the CROSSOVER
Mode
Set the MODE Switches to the STereo posi-
tion to configure the amplifier for two chan-
nel operation. Refer to figure 8.
Figure 7
Switch is in the HP (high fre-
quency pass) Position, the Ampli-
fier will pass all frequencies
Figure 4
Crossover
Set the CROSSOVER Switch to the OUT position since
both channels are operating at full frequency range. Refer
to figure 4.
above the setting of the CROSSOVER FREQUENCY
Control. Refer to figure 4.
Equalizer
Operating in Bridged Subwoofer Mode
Both channels (1 and 2) are 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 lo-
cated by real-time analysis with an
RTA) in your system’s frequency re-
sponse. If you are attempting to
Input Source
Set the SOURCE Switch to the 1-2 (SUB)
position. Refer to figure 7.
Output Mode
Set the MODE Switch to the BRIDGED Po-
sition to operate in the Bridged Subwoofer
equalize a system without RTA data,
play music you are familiar with, set
Figure 8
Figure 5
Mode. Refer to figure 8.
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 deter-
mine its equalization needs. Subtle adjustments are best
and cutting usually sounds better than boosting. Refer to
figure 5.
Crossover
Set the CROSSOVER Switch to the LP Position. Adjust
the CROSSOVER FREQUENCY Control for the Cross-
over Frequency that is recommended by the Manufacturer
of the Loudspeaker for the best performance. Refer to fig-
ure 4.
11
How to Replace the Fuses
How to Replace the Fuses
If the MCC302 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 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
(or DC Power Supply) as Potentially Dangerous
Currents exist inside the amplifier.
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, one is located above
the row of Controls/Switches and the other near the
Bottom Edge of the Gold Faceplate Control Panel.
6. Remove all 5 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.
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.
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
pliers, then push it the rest of the way in with your
finger to avoid having the pliers slip and hit the
circuit board.
11. Re-install the Gold Faceplate Control Panel and all 5
crossover, equalizer and sensitivity knobs.
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.
12
MCC302 Block Diagram
Specifications
Specifications
Power Output Per Channel
Intermodulation Distortion
150 watts into 4 ohm loads and 300 watts into 2 ohm loads
is the minimum sine wave continuous average power out-
put per channel, with both channels operating.
Maximum Intermodulation Distortion if instanta-
neous peak output per channel does not exceed
twice the rated output, for any combination of fre-
quencies from 20Hz to 20,000Hz, with all channels
operating is:
Power Output Bridged
600 watts into 4 ohm loads is the minimum sine wave con-
tinuous average power output.
0.005% for 4 ohm loads
0.008% for 2 ohm loads
0.008% for Bridged Mode with 4 ohm loads
Rated Power Band
20Hz to 20,000Hz
Input Impedance
12,000 ohms
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
Power Requirements
12 Volts DC, 2.5 amps (idle) - 50 amps (150 watts)
Dimensions
0.008% for 2 ohm loads
12.5 inches (31.8cm) wide, 3.0 inches (7.6cm)
high, 13.7 inches (34.8cm) depth
0.008% for Bridged Mode with 4 ohm loads
Dymanic Headroom
1dB
Weight
14.5 pounds (6.6Kg) net, 17 pounds (7.7Kg) in
shipping carton
Frequency Response
+0, -0.25dB from 20Hz to 20,000Hz
+0, -3dB from 10Hz to 100,000Hz
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 vari-
able 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 Exter-
nal Subwoofer Rotary Control)
14
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.
Quantity Part Number
Description
Shipping carton only
End cap (Foam pad)
1
2
034162
034132
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 Labo-
ratory. Please see the Part List for the correct part numbers.
15
McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, NY 13903
McIntosh Part No. 040757
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