McIntosh MC-452 User Manual

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

MC452

Quad Balanced

Power Amplier

Owner’s Manual

The lightning ash with arrowhead, within an equilateral
triangle, is intended to alert the user to the presence of

uninsulated “dangerous voltage” within the product’s en-

closure that may be of sufcient magnitude to constitute
a risk of electric shock to persons.

The exclamation point within an equilateral triangle is
intended to alert the user to the presence of important

operating and maintenance (servicing) instructions in the

literature accompanying the appliance.

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.

1. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

5. Do not use this apparatus near water.

6. Clean only with a 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 appa-

ratus (including ampliers) 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

NO USER-SERVICEABLE PARTS

INSIDE. REFER SERVICING TO

QUALIFIED PERSONNEL.

third grounding prong. The wide blade or the
third prong are provided for your safety. If

the provided plug does not t 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 specied by

the manufacturer.

12. Use only with the cart, stand, tripod, bracket,
or table specied 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 qualied service person­nel. Servicing is required when the apparatus
has been damaged in any way, such as power-

To prevent the risk of electric

shock, do not remove cover or

back. No user-serviceable parts

inside.

supply cord or plug is damaged, liquid has
been spilled or objects have fallen into the
apparatus, the apparatus has been exposed to
rain or moisture, does not operate normally, or
has been dropped.

15. Do not expose this equipment to dripping or

splashing and ensure that no objects lled

with liquids, such as vases, are placed on the
equipment.

16. To completely disconnect this equipment from
the a.c. mains, disconnect the power supply
cord plug from the a.c. receptacle.

17. The mains plug of the power supply cord shall
remain readily operable.

18. Do not expose batteries to excessive heat such

as sunshine, re or the like.

19. Connect mains power supply cord only to a
mains socket outlet with a protective earthing
connection.

2

Thank You

Your decision to own this McIntosh MC452 Quad
Balanced 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]

Copyright 2010 © by McIntosh Laboratory, Inc.

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
Department. For assistance on factory repair return
procedure, contact the McIntosh Service Department
at:
McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, New York 13903
Phone: [phone]
Fax: [phone]

Table of Contents

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

Thank You and Please Take a Moment .......................3

Technical Assistance and Customer Service ..............3

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

General Information ...................................................3

Connector and Cable Information ..............................4

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

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

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

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

Rear Panel Connections and Switch ...........................7

How to Connect ...................................................... 8-9

How to Connect for Bi-Amp ................................ 10 -11

Front Panel Displays and Controls ............................12

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

Technical Description .......................................... 14 -17

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

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

General Information

1. The following Connecting Cable is available from
the McIntosh Parts Department:

Power Control Cable Part No. 170-202

Six foot, 2 conductor shielded, with two 1/8 inch
stereo mini phone plugs.

2. For additional connection information, refer to the

owner’s manual(s) for any component(s) connected

to the MC452.

3. The MC452 mutes the speaker output for approxi­mately two seconds when first turned on.

4. For the best performance and safety it is important
to always match the impedance of the loudspeaker
to the Power Amplifier connections. Refer to “How
to Connect” pages 8 thru 11.

Note: The impedance of a Loudspeaker actually var-

ies as the Loudspeaker reproduces different
frequencies. As a result, the nominal impedance
rating of the Loudspeaker (usually measured at
a midrange frequency) might not always agree
with the impedance of the Loudspeaker at low
frequencies where the greatest amount of power
is required. Contact the Loudspeaker Manufac­turer for additional information about the actual
impedance of the Loudspeaker before connecting

it to the McIntosh MC452.

5. In the event the MC452 over heats, due to improper
ventilation and/or high ambient temperature, the
protection circuits will activate. The Front Panel
Power Guard LED will continuously indicate ON
and the audio will be muted. When the MC452 has
returned to a safe operating temperature, normal
operation will resume.

6. When discarding the unit, comply with local rules
or regulations. Batteries should never be
thrown away or incinerated but disposed
of in accordance with the local regulations
concerning battery disposal.

7. For additional information on the MC452
and other McIntosh Products please visit
the McIntosh Web Site at www.mcintosh­labs.com.

3

Cable Information, Introduction and Performance Features

PIN 2 PIN 1

PIN 3

PIN 1

PIN 2

PIN 3

Trigger
Control

Ground

Meter
Illumination
Control

Connector and Cable Information

XLR Connectors

Below is the Pin configuration for the XLR Balanced
Input, Input/Output Connectors on the MC452. Refer
to the diagram for connection:
PIN 1: Shield/Ground

IN

OUT

PIN 2: + Input/Output
PIN 3: - Input/Output

Power Control Connector

The MC452 Power Control Input receives an On/Off
signal from +5 to +12 volts. The Power Control Output
will in turn provide a +12 volt
Output Signal with a total cur­rent up to 50mA. An additional
connection is for controlling
the illumination of the MC452
Power Output Meters. The 1/8
inch stereo mini phone plug connects to a McIntosh
Preamplifier or A/V Control Center Power Control
Output.

Note: The Power Control Connecting Cable is available

from the McIntosh Parts Department:

Data and Power Control Cable Part No. 170-202

Six foot, shielded 2 conductor, with 1/8 inch stereo
mini phone plugs on each end.

Introduction

Now you can take advantage of traditional McIntosh
standards of excellence in the MC452 Quad Balanced
Power Amplifier. The 450 watts power per channel
high current output will drive any pair of high quality
Loudspeakers. The MC452 reproduction is sonically
transparent and absolutely accurate. The McIntosh
Sound is “The Sound of the Music Itself.”

4

Performance Features

• Power Output

The MC452 is a Power Amplifier with a capability
of 450 watts per channel into 2, 4 or 8 ohm speakers
with less than 0.005% distortion. The Power Amplifier
Circuitry uses Thermal Trak1 Output Transistors for
lower distortion and cool operation.

• Quad Balanced Circuitry

The MC452 is fully balanced from inputs to outputs.
It consists of two matched power amplifiers operating
in push-pull with their outputs combined in a McIn­tosh Autoformer. The Quad Balanced configuration
cancels virtually all distortion.

• Patented Autoformer

McIntosh designed and manufactured Output Auto­formers provide an ideal match between the amplifier
output stages and speaker loads of 2, 4 and 8 ohms.
The Autoformers also provide perfect DC protection
for your valuable loudspeakers.

• Balanced and Unbalanced Inputs

Balanced connections guard against induced noise and
allow long cable runs without compromising sound
qualit y.

• Power Guard

The patented McIntosh Power Guard circuit prevents
the amplifier from being over driven into clipping,
with its harsh distorted sound that can also damage
your valuable loudspeakers.

• Sentry Monitor and Thermal Protection

McIntosh Sentry Monitor power output stage protec­tion circuits ensure the MC452 will have a long and

1

ThermalTrak™ and ON Semiconductor are trademarks of Semi-

conductor Components Industries, LLC

trouble free operating life. Built-in Thermal Protection
Circuits guard against overheating.

• Special Power Supply

A very large Power Transformer and Large Capaci­tors ensure stable noise free operation even though the
power line varies.

• Illuminated Power Meters

The Illuminated Power Output Watt Meters on the
MC452 are peak responding, and indicate the true
power output of the amplifier. The Peak Watt Hold
Mode allows the meter to temporarily stay at the high­est power output and then slowly decay. The Front
Panel Meter Illumination may be switched Off at any
time.

• McIntosh Custom Binding Posts

McIntosh patent pending gold plated output terminals
deliver high current output. They accept large diam­eter wire and spade lugs. Banana plugs may also be
used only in the United States and Canada.

• Fiber Optic Solid State Front Panel Illumination

The even Illumination of the Front Panel is accom­plished by the combination of custom designed Fiber
Optic Light Diffusers and extra long life Light Emit-

ting Diodes (LEDs).

• Glass Front Panel and Super Mirror Chassis
Finish

The famous McIntosh Illuminated Glass Front Panel
and the Stainless Steel Chassis with Super Mirror Fin­ish ensures the pristine beauty of the MC452 will be
retained for many years.

Dimensions

Front View of the MC452

Rear View of the MC452

Side View of the MC452

17-1/2"

44.45cm

8-7/8"

22.54cm

9-7/16"

23.97cm

11-3/4"

29.85cm

16-13/16"

42.70cm

20-3/16"

51.27cm

3/16"

0.48cm

17-15/16"

45.55cm

2-1/4"

5.71cm

13"

33.02cm

8-3/8"

21.27cm

2-3/16"

5.55cm

The following dimensions can assist in determining
the best location for your MC452.

Dimensions

5

Installation

14-11/16"

37.30cm

17"

43.18cm

Cutout Opening for Custom Mounting

Opening for Ventilation

Cabinet Front Panel

MC452 Front Panel
Custom Cabinet Cutout

Cutout Opening for Ventilation

Support
Shelf

Chassis
Spacers

MC452 Side View
in Custom Cabinet

Cabinet
Front
Panel

Note: Center the cutout Horizontally
on the unit. For purposes of
clarity, the above illustration
is not drawn to scale.

MC452 Bottom View
in Custom Cabinet

6"

15.24cm

Opening
for Ventilation

12-3/4"

32.38cm

Cutout Opening
for Ventilation

16"

40.64cm

2-1/2"

6.35cm

The MC452 can be placed upright on a table or
shelf, standing on its four feet. It also can be custom
installed in a piece of furniture or cabinet of your
choice. The four feet may be removed from the bottom
of the MC452 when it is custom installed as outlined
below. The four feet together with the mounting
screws should be retained for possible future use if the
MC452 is removed from the custom installation and
used free standing. The required panel cutout, ventila­tion cutout and unit dimensions are shown.
Always provide adequate ventilation for your MC452.
Cool operation ensures the longest possible operating
life for any electronic instrument. Do not install the
MC452 directly above a heat generating component
such as a high powered amplifier. If all the compo­nents are installed in a single cabinet, a quiet running
ventilation fan can be a definite asset in maintaining
all the system components at the coolest possible oper­ating temperature.
A custom cabinet installation should provide the fol­lowing minimum spacing dimensions for cool opera­tion.

Allow at least 6 inches (15.24cm) above the top, 2
inches (5.08cm) below the bottom, 3 inches (7.62cm)
behind the rear panel and 2 inches (5.08cm) on each

side of the Power Amplifier, so that airflow is not

obstructed. Allow 2-1/2 inches (6.35 cm) in front of

the mounting1 panel for clearance. Be sure to cut out
a ventilation hole in the mounting shelf according
to the dimensions in the drawing.

Installation

1

When the MC452 is installed together with other McIn-

tosh Components, check clearances on all components
before proceeding.

6