McIntosh MC207 User Manual

Seven Channel Power Amplifier

MC207

Owner’s Manual

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

The lightning flash with arrowhead,
within an equilateral triangle, is intended
to alert the user to the presence of
uninsulated “dangerous voltage” within
the product’s enclosure that may be of
sufficient 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
apparatus (including amplifiers) 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 are
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.

NO USER-SERVICEABLE PARTS

INSIDE. REFER SERVICING TO

QUALIFIED PERSONNEL.

To prevent the risk of electric shock, do not remove cover or

back. No user-serviceable parts inside.

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

12. Use only with the cart, stand, tripod, bracket, or
table specified by the manufacturer,
or sold with the apparatus. When a
cart is used, use caution when moving
the cart/apparatus combination to
avoid injury from 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 power-supply
cord or plug is damaged, liquid has been spilled
or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture,
does not operate normally, or has been dropped.

15. Do not expose this equipment to dripping or
splashing and ensure that no objects filled 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.

2

Thank Y ou

Your decision to own this McIntosh MC207 Seven 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:

Table of Contents

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

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

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

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

Important Information ...................................................... 3

Connector Information ..................................................... 4

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

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

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

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

Rear Panel Connections.................................................... 7

How to Connect for Seven Channels................................ 8

How to Connect for Five Channels ................................ 10

How to Connect for Two Channels (Zone B)................. 12

Front Panel Displays and Controls ................................. 14

How to Operate and Read the Power Output Meters ..... 15

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

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

Important Information

T echnical 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 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]

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 MC207.

3. The MC207 mutes the speaker outputs for approximately two
seconds when first turned on.

4. It is very important that loudspeaker cables of adequate size
be used, so that there will be no power loss. The size is
specified in Gauge Numbers or AWG (American Wire Gauge).
The smaller the Gauge number, the larger the wire size. The
MC207 Loudspeaker Connection Terminals will accept up to a
10 AWG wire size:

If your loudspeaker cables are 50 feet (38.1m) or less,
use at least 14 Gauge.
If your loudspeaker cables are 100 feet (76.2m) or less,
use at least 12 Gauge.

5. In the event that the MC207 overheats, due to improper
ventilation and/or high ambient temperature, the protection
circuits will activate. The Front Panel Power Guard LEDs
will continuously indicate ON and the audio will be muted.
When the MC207 has returned to a safe operating
temperature, normal operation will resume.

6. The Multi-Channel Input DB25 Connector allows for easy
connecting of a McIntosh MX134 or MX135 A/V Control
Center, including the Audio and Power Control signals, to the
MC207.

Copyright 2004 © by McIntosh Laboratory, Inc.

3

Connector Information

Connector Information, Introduction and Performance Features

XLR Connectors

Below is the Pin configuration for the XLR Balanced Input
Connectors on the MC207. Refer to the diagram for con­nection:

PIN 1: Shield/Ground
PIN 2: + Input
PIN 3: - Input

Power Control and Trigger Connectors

The MC207’s Power Control Outputs provide a 5 volt sig­nal. Use a 1/8 inch stereo mini
phone plug to connect to the
Power Control Input on other
McIntosh Components.

Multi-Channel Amp DB25 Connector Pin Layout

1. Left Front + 15. Center Front Gnd.

2. Center Front + 16. Right Front Gnd.

3. Right Front + 17. N/C

4. N/C 18. Left Surround Gnd.

5. Left Surround + 19. Right Surround Gnd.

6. Right Surround + 20. Left Back Surround Gnd.

7. Left Back Surround + 21. Right Back Surround Gnd.

8. Right Back Surround + 22. N/C

9. N/C 23. N/C

10. N/C 24. System Calibrate Gnd.

11. N/C 25. Power Control Gnd.

12. System Calibrate

13. Power Control In

14. Left Front Gnd.

Pin 2

Positive

Multi-Channel Input

Pin 1
Pin 3

N/C

Ground

••

• Patented 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.

••

Dynamic Power Manager

•

••

The MC207’s Dynamic Power Manager (DPM) circuitry
allows for the connection of either 4 ohm or 8 ohm Loud­speakers, while at the same time delivering identical power
output. A peak output current of 25 amperes per channel
ensures that it will successfully drive high quality Loud­speakers such as McIntosh for a truly exciting sound expe­rience.

••

• Balanced and Unbalanced Inputs

••

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

••

• Patented Sentry Monitor with Thermal Protection

••

McIntosh Sentry Monitor power output stage protection
circuits ensure the MC207 will have a long and trouble free
operating life. Built-in Thermal Protection Circuits guard
against overheating.

••

• Power Control

••

The McIntosh Power Control Circuit allows for remote
turn-on of the MC207 Power Amplifier from a McIntosh
A/V Control Center or Preamplifier for a single or dual
Zone System.

TM

Introduction

Now you can take advantage of traditional McIntosh stan­dards of excellence in the MC207 Power Amplifier. Seven
200 watt high current output channels will drive any high
quality Loudspeaker System to its ultimate performance.
The MC207 reproduction is sonically transparent and abso­lutely accurate. The McIntosh Sound is “The Sound of the
Music Itself.”

Performance Features

••

• Power Output

••

The MC207 consists of seven Power Amplifier Channels,
each capable of 200 watts into 4 ohm or 8 ohm Loudspeak­ers with less than 0.005% distortion.

4

••

• Illuminated Power Meters

••

The Illuminated Power Output Watt Meters on the MC207
are peak responding, and indicate the power output of the
Front Amplifier Channels. The Meter Illumination may be
switched Off at any time.

••

• Fiber Optic Solid State Front Panel Illumination

••

The Illumination of the Front Panel is accomplished by the
combination of custom designed Fiber Optic Light Diffus­ers and Light Emitting Diodes (LEDs). This provides even
Front Panel Illumination, together with the extra long life
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 ensure
the pristine beauty of the MC207 will be retained for many
years.

Dimensions

The following dimensions can assist in determining the
best location for the MC207. There is additional informa­tion on the next page pertaining to installing the MC207
into cabinets.

Front View of the MC207

17-

1/2

44.45cm

Dimensions

"

8-

7/8

"

9-

7/16

22.54cm

23.97cm

"

Rear View of the MC207

Side View of the MC207

16

-13/16

42.70cm

11-

3/4

29.85cm

18-

47.63cm

16

41.75cm

"

3/4

-7/16

"

"

"

8-

1/4

3/16

"

0.48cm

"

20.96cm

7/8

"

2.22cm

12"

30.48cm

2"

5.08cm

5

Installation

Installation

The MC207 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 MC207 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 MC207 is removed from the custom instal­lation and used free standing. It also can be custom in­stalled in a piece of
furniture or cabinet
of your choice The
required panel cut­out, ventilation cut­out and unit dimen­sions are shown.

Always provide
adequate ventilation
for your MC207.

MC207 Front Panel
Custom Cabinet Cutout

Cool operation en­sures the longest
possible operating
life for any elec­tronic instrument.
Do not install the
MC207 directly
above a heat gener­ating component
such as a high pow­ered amplifier. If all

Opening
for Ventilation

the components are
installed in a single
cabinet, a quiet run­ning ventilation fan
can be a definite as-

MC207 Side View
in Custom Cabinet

set in maintaining
all the system com­ponents at the
coolest possible op-

Support
Shelf

erating temperature.

A custom cabinet
installation should
provide the follow­ing minimum spac­ing dimensions for
cool operation. Al­low at least 6 inches
(15.24cm) above the

MC207 Bottom View
in Custom Cabinet

Center the

opening horizontally

with the

MC207 Chassis

top, 2 inches

(3.81cm) below the bottom and 1 inch (2.54cm) on each
side of the amplifier, so that airflow is not obstructed. Al­low 20 inches (50.8cm) depth behind the front panel. Al­low 1 inch (2.54cm) in front of the mounting panel for
knob clearance. Be sure to cut out a ventilation hole in the
mounting shelf according to the dimensions in the drawing.

17-

1/16

"

43.34cm

8-

21.11cm

6"

Cabinet
Front
Panel

15.24cm

3

8.57cm

12

31.12cm
Cutout

Opening

for

Ventilation

9

25.08cm

11

29.21cm

Cutout Opening for Ventilation

-3/4

-1/4

-7/8

Cutout Opening
for
Custom Mounting

"

"

15

-3/4

40.00cm

"

-1/2

"

11"

27.9cm

"

Chassis
Spacers

12

-3/8

31.43cm

5/16

"

"

6

Rear Panel Connections and Switch

Connect the
MC207 power cord
to a live AC outlet.
Refer to informa­tion on the back
panel to determine
the correct voltage

Resettable Circuit
Breaker

OUPUT Connections
for 4 ohm or 8 ohm
Loudspeaker for
Channel 7 (Right
Front)

OUPUT Connections
for 4 ohm or 8 ohm
Loudspeaker for
Channel 6 (Right
Back) or Right Chan­nel for Zone B

OUPUT Connections
for 4 ohm or 8 ohm
Loudspeaker for
Channel 5 (Left Back)
or Left Channel for
Zone B

OUPUT Connections
for 4 ohm or 8 ohm
Loudspeaker for
Channel 4 (Center
Front)

OUPUT Connections
for 4 ohm or 8 ohm
Loudspeaker for Chan­nel 1 (Left Front)

OUPUT Connections
for 4 ohm or 8 ohm
Loudspeaker for Chan­nel 2 (Left Surround)

OUPUT Connections
for 4 ohm or 8 ohm
Loudspeaker for
Channel 3 (Right Sur­round)

Selects the imped­ance (4 or 8 ohms)
of the Loudspeak­ers connected to
the MC207

POWER CONTROL ZA receives
turn On/Off signals from a McIntosh
component for Zone A (Channels 1-

7). POWER CONTROL ZB receives
turn On/Off signals from a McIntosh
component for Zone B (Channels 5
and 6).

Balanced INPUTS
(7) for discrete au­dio cables from an
A/V Control Center
or Preamplifier Au­dio Outputs

Balanced INPUTS
(5-6) for discrete
audio cables from
an A/V Control
Center or Pream­plifier Audio Out­puts

Unbalanced INPUTS
(6-7) for discrete audio
cables from an A/V
Control Center or
Preamplifier Audio Out­puts

Balanced INPUTS
(3-4) for discrete
audio cables from
an A/V Control
Center or Pream­plifier Audio Out­puts

Unbalanced INPUTS
(4-5) for discrete audio
cables from an A/V
Control Center or
Preamplifier Audio Out­puts

Balanced INPUTS
(1-2) for discrete
audio cables from
an A/V Control
Center or Preampli­fier Audio Outputs

Unbalanced INPUTS (1-3)
for discrete audio cables
from an A/V Control Center
or Preamplifier Audio Out­puts

MULTI­CHANNEL
INPUT ac­cepts a 25
conductor
DB25 com­puter type
cable that
connects all
audio and
power con­trol signals

7

How to Connect for Seven Channels

Caution: The supplied AC Power Cord should not be

connected to the Rear Panel of the MC207
Amplifier until after the Loudspeaker Connections
have been made. Failure to observe this could
result in Electric Shock.

1. Connect Balanced Audio Cables from the Zone A Out­puts of a McIntosh A/V Control Center to the MC207
INPUTS (Channels 1-7), making sure to match up the
channel identifications between both units.

Note: In place of the Balanced Audio Cables, unbalanced

cables may be used. If a DB25 cable is used between
the MULTI-CHANNEL INPUT of the MC207 and the
Multi-Channel Output, the separate Power Control
cable is not needed, proceed to step 3.

2. Connect a power control cable from the McIntosh A/V
Control Center Zone A Power Control Out to the
MC207 POWER CONTROL ZA.

3. Prepare the
Loudspeaker
Hookup Cables
that attach to the
MC207 Power
Amplifier by
choosing one of
the methods below:

Bare wire cable ends:
Carefully remove sufficient insulation from the cable
ends, refer to figures 1, 2 & 3. If the cable is stranded,
carefully twist the strands together as tightly as pos­sible.

Note: If desired, the twisted ends can be tinned with

solder to keep the strands together, or attach spade
lug and/or banana connector.

Spade lug or prepared wire connection:
Insert the spade lug connector or
prepared section of the cable end
into the terminal side access hole,
and tighten the terminal cap until
the cable is firmly clamped into the
terminal so the wires cannot slip
out. Refer to figures 4, 5 & 6.

Banana plug connection:
Tighten the top portion of the terminal post and insert
the banana plug into the opening
at the top of the terminal. Refer
to figure 7.

Note: The use of Banana Plugs is

for use in the United States
and Canada only.

4. Connect the Loudspeaker
Hookup Cables from the MC207
OUTPUT Terminals to the Loud­speakers, being careful to observe the correct polarities
and channel designation.

WARNING: Loudspeaker terminals are hazardous live

and present a risk of electric shock. For
additional instruction on making
Loudspeaker Connections contact your
McIntosh Dealer or McIntosh Technical
Support.

5. Place the IMPEDANCE Switch to the position (4 ohm
or 8 ohm) that matches the impedance of the connected
Loudspeakers. In the event that some of the Loud­speakers in the system are of different impedance, use
the impedance of the Left and Right Front Loudspeak­ers to set the IMPEDANCE Switch position.

6. Connect the MC207 Power Cord to an active AC out­let.

McIntosh A/V Control Center

8

How to Connect for Seven Channels

Left Front
Loudspeaker

Center Front
Loudspeaker

Right Front
Loudspeaker

Left Surround
Loudspeaker

To AC
Outlet

Back Surround
Loudspeaker

Right Surround
Loudspeaker

Back Surround
Loudspeaker

9

How to Connect for Five Channels

Caution: The supplied AC Power Cord should not be

connected to the Rear Panel of the MC207
Amplifier until after the Loudspeaker Connections
have been made. Failure to observe this could
result in Electric Shock.

1. Connect Balanced Audio Cables from the Zone A Out­puts of a McIntosh A/V Control Center to the MC207
INPUTS (Channels 1-4 and 7), making sure to match up
the channel identifications between both units.

Note: In place of the Balanced Audio Cables, unbalanced

cables may be used. If a DB25 cable is used between
the MULTI-CHANNEL INPUT of the MC207 and the
Multi-Channel Output, the separate Power Control
Cable ZA is not needed.

2. Connect a power control cable from the McIntosh A/V
Control Center Zone A Power Control Out to the
MC207 POWER CONTROL ZA.

3. Prepare the Loudspeaker Hookup Cables that attach to
the MC207 Power Amplifier by choosing one of the
methods below:

Bare wire cable ends:
Carefully remove sufficient insulation from the cable
ends, refer to figures 1, 2 & 3. If the cable is stranded,
carefully twist the strands together as tightly as pos­sible.

Note: If

desired,
the
twisted
ends can
be tinned with solder to keep the strands together,
or attach spade lug and/or banana connector.

Spade lug or prepared wire connection:
Insert the spade lug connector or prepared section of
the cable end into the terminal side
access hole, and tighten the terminal
cap until the cable is firmly clamped
into the terminal so the wires cannot
slip out. Refer to figures 4, 5 & 6.

Banana plug connection:
Tighten the top portion of the terminal post and insert
the banana plug into the opening at the top of the ter­minal. Refer to figure 7.

Note: The use of Banana Plugs is

for use in the United States
and Canada only.

4. Connect the Loudspeaker
Hookup Cables from the MC207
OUTPUT Terminals to the Loud­speakers, being careful to ob­serve the correct polarities and
channel designation.

WARNING: Loudspeaker terminals are hazardous live

and present a risk of electric shock. For
additional instruction on making
Loudspeaker Connections contact your
McIntosh Dealer or McIntosh Technical
Support.

5. Place the IMPEDANCE Switch to the position (4 ohm
or 8 ohm) that matches the impedance of the connected
Loudspeakers. In the event that some of the Loud­speakers in the system are of different impedance, use
the impedance of the Left and Right Front Loudspeak­ers to set the IMPEDANCE Switch position.

Note: If the two remaining channels (5 and 6) are to be

used for Zone B operation, proceed to page 12.

6. Connect the MC207 Power Cord to an active AC out­let.

McIntosh A/V Control Center

10

How to Connect for Five Channels

Left Front
Loudspeaker

Center Front
Loudspeaker

Right Front
Loudspeaker

Left Surround
Loudspeaker

To AC
Outlet

Right Surround
Loudspeaker

11

How to Connect for Two Channels (Zone B)

Caution: The supplied AC Power Cord should not be

connected to the Rear Panel of the MC207
Amplifier until after the Loudspeaker Connections
have been made. Failure to observe this could
result in Electric Shock.

1. Connect Audio Cables from the Zone B Outputs of a
McIntosh A/V Control Center to the MC207 INPUTS
(Channels 5 and 6), making sure to match up the chan­nel identifications between both units.

2. Connect a power control cable from the McIntosh A/V
Control Center Zone B Power Control Out to the
MC207 POWER CONTROL ZB.

3. Prepare the Loudspeaker Hookup Cables that attach to
the MC207 Power Amplifier by choosing one of the
methods below:

Bare wire cable ends:
Carefully remove sufficient insulation from the cable
ends, refer to
figures 1, 2 &

3. If the cable
is stranded,
carefully twist
the strands to­gether as tightly as possible.

Note: If desired, the twisted ends can be tinned with

solder to keep the strands together, or attach spade
lug and/or banana connector.

Spade lug or prepared wire connection:
Insert the spade lug connector or prepared section of
the cable end into the terminal side access hole, and
tighten the terminal cap until the cable is firmly
clamped into the terminal so the wires cannot slip out.
Refer to figures 4, 5 & 6.

Banana plug connection:
Tighten the top portion of the terminal post and insert
the banana plug into the opening at the top of the ter­minal. Refer to figure 7.

Note: The use of Banana Plugs is

for use in the United States
and Canada only.

4. Connect the Loudspeaker
Hookup Cables from the MC207
OUTPUT Terminals to the Loud­speakers, being careful to ob­serve the correct polarities and
channel designation.

WARNING: Loudspeaker terminals are hazardous live

and present a risk of electric shock. For
additional instruction on making
Loudspeaker Connections contact your
McIntosh Dealer or McIntosh Technical
Support.

5. Place the IMPEDANCE Switch to the position (4 ohm
or 8 ohm) that matches the impedance of the connected
Loudspeakers. In the event that some of the Loud­speakers in the system are of different impedance, use
the impedance of the Left and Right Front Loudspeak­ers to set the IMPEDANCE Switch position.

6. Connect the MC207 Power Cord to an active AC out­let.

12

McIntosh A/V Control Center

How to Connect for Two Channels (Zone B)

To AC
Outlet

Left Channel
(Zone B)

Right Channel
(Zone B)

13

Front Panel Displays and Controls

POWER OUTPUT METER
indicates power output of the
Left Front Channel (1)

POWER GUARD LED
lights when the Left Front
Channel (1) POWER
GUARD Circuit activates

POWER OUTPUT METER
indicates power output of the
Center Front Channel (4)

POWER GUARD LED
lights when the Center
Front Channel (4) POWER
GUARD Circuit activates

POWER OUTPUT METER
indicates power output of the
Right Front Channel (7)

POWER GUARD LED
lights when the Right Front
Channel (7) POWER
GUARD Circuit activates

14

METER LIGHTS
Switch selects the
Meter Illumination
On or Off

Remote On Indicator
lights when the amplifier
is in the Remote Turn-On
Mode

POWER GUARD LEDs light
when the Left Surround Chan­nel (2), Right Surround Chan­nel (3), Left Back Surround
Channel (5) or Right Back Sur­round Channel (6) POWER
GUARD Circuit activates

POWER Switch Turns
AC Power Off, Remote
(On/Off), or On

How to Operate and Read the Power Output Meters

How to Operate

Power On

With the POWER Switch set to the REMOTE Position, the
MC207 will turn On or Off when
an A/V Control Center turns On or
Off. For manual operation, rotate
the POWER Switch to the ON or
OFF Position as desired. Refer to
figure 8.

Note: There must be a power

control connection between
the MC207 and the McIntosh
A/V Control Center in order
for the remote power turn-on
to function.

Meter Illumination

Rotate the METER LIGHTS Switch to select Meter Illumi­nation On or Off. Refer to figure 9.

Note: When the MC207 is

connected to a McIntosh
MX132, MX134 or MX135
A/V Control Center with a
DB25 conductor cable, the
meter illumination will
automatically switch On
during the Loudspeaker Level
Setup Adjustment.

Impedance Switch

The MC207’s Dynamic Power Manager circuitry allows
for the connection of either 4 ohm or 8
ohm Loudspeakers to its output terminals,
while at the same time delivering the same
power output. Refer to figure 10. Place the
IMPEDANCE Switch to the position (4
ohm or 8 ohm) that matches the im­pedance of the connected Loudspeak­ers. In the event that some of the
Loudspeakers in the system are of
different impedance, use the imped­ance of the Left and Right Front
Loudspeakers to set the IMPED­ANCE Switch position. Refer to figure 11.

Figure 8

Figure 9

Figure 10

Figure 11

How to Read the Power Output Meters

The MC207 Power Output Meters are calibrated to allow
for the direct reading of either the Power Output in Watts
or Decibels going to the Front Left, Center and Right
Loudspeakers. The meters respond to all the musical infor­mation being produced by the amplifier. They indicate to
an accuracy of at least 95% of the power output with only
a single cycle of a 2000Hz tone burst. Refer to figure 12.

Figure 12

15

T echnical Description

McIntosh Laboratory, the company who introduced the
world’s first amplifier that could be called “High Fidelity”,
has done it again. The McIntosh engineering staff has cre­ated a power amplifier without compromise, using the most
advanced McIntosh circuit design concepts.

A continuous average power output rating of 200 watts
and an output current of greater than 25 amperes per chan­nel, makes this one of the most advanced and powerful am­plifiers McIntosh has ever manufactured. The distortion
limits for the MC207 are no more than 0.005% at rated
power output for all frequencies from 20Hz to 20,000Hz.
Typical performance at mid frequencies is less than

0.002%. The true distortion readings on the MC207 are so
low, it takes special measuring techniques to make accurate
readings. The MC207 can deliver the best possible perfor­mance from any type of high quality Loudspeaker System.

Creating an amplifier with this level of performance did
not come easily. Many months of design, testing and mea­suring were required. Extensive controlled listening tests,
the ultimate form of measuring, were made before the final
design was accepted.

Design Philosophy

The design philosophy incorporated in the MC207 in­volved several different techniques, all based on sound sci­entific logic. Refer to figure 13. Every stage of voltage or
current amplification must be as linear as possible prior to
the use of negative feedback. McIntosh engineers know
how to properly design negative feedback circuits so they
contribute to the extremely low distortion performance ex­pected from a McIntosh amplifier. The typical McIntosh
owner would never accept the approximately 100 times

16

Inside View of the MC207

Block Diagram of the Amplifiers

and

Meter Circuitry

T echnical Description

(One of Seven Channels Illustrated)

higher distortion of many non-feedback designs.

All transistors are selected to have nearly constant cur­rent gain over the entire current range they must cover.
Output transistors in par­ticular, have matched
uniform current gain,
high current-bandwidth
product and large active
region safe operating
area. T o accommodate
the high current demands
of a 4 ohm loudspeaker,
the MC207 Output Cir­cuitry utilizes a multi­plicity of power output
transistors. Refer to fig­ure 14. An automatic
tracking bias system
completely eliminates
any trace of crossover
distortion. Precision
metal film resistors and
low dielectric absorption
film capacitors are used
in all critical circuit loca­tions.

Figure 13

The MC207 is the first McIntosh Power Amplifier to
use the newly developed Dynamic Power Manager
(DPM) Circuitry. Refer to figure 15 on the next page.

TM

Figure 14

17

Figure 15

The MC207 can easily drive 4 ohm speakers, with their
high current demand. Additionally, the MC207 can be used
with 8 ohm speakers, and deliver equal power. McIntosh’s
new DPMTM design enables it to run on higher voltage rails
when connected to less current-hungry 8 ohm speakers and
still deliver 200 watts. The power penalty usually paid with
8 ohm speakers on high current amplifiers does not exist
with this new design.

The high efficiency circuit design of the MC207 con­tributes to
low oper­ating tem­peratures.
More than
2625
square
inches of
heat sink
area occu­pies al­most half
of the
MC207’s
chassis
space and
keeps the
amplifier
operating
safely
with con­vection

Figure 16

cooling. No fans are needed. Refer to figure 16.

Protection Circuits

The MC207 incorporates its version of the McIntosh Sen­try Monitor out­put transistor
protection cir­cuit. Refer to
figure 17. There
is absolutely no
compromise in
sonic perfor­mance with this
circuit, and it
ensures safe op­eration of the
amplifier under
even the most
extreme operat-

Figure 17

Input Test Signal

ing conditions.
The different
types of protec­tion circuits in­corporated in
the MC207 in­sure a long and
safe operating
life.

The MC207
also includes the
unique patented
McIntosh Power
Guard circuit.
Power Guard

Figure 18

eliminates the
possibility of

Without Power Guard

ever overdriving
the amplifier
into clipping.
Refer to figures
18, 19 and 20.
An overdriven
amplifier can
produce both
audible and in­audible distor­tion levels ex­ceeding 40%.
The audible dis­tortion is un­pleasant to hear,

Figure 19

18

Technical Description, con’t

but the inaudible

With Power Guard

ultrasonic dis­tortion is also
undesirable,
since it can
damage valuable
Loudspeaker
System tweet­ers. You will
never experi­ence the harsh
and damaging
distortion due to
clipping.

The Power

Guard circuit is

Figure 20

a waveform
comparator, monitoring both the input and output wave­forms. Under normal operating conditions, there are no dif­ferences between the shape of these waveforms. If an am­plifier channel is overdriven, there will be a difference be­tween the two signal waveforms. When the difference ex­ceeds 0.3% (equivalent to 0.3% harmonic distortion), the
Power Guard activates the PG light and a dynamic elec­tronic attenuator at the amplifier input reduces the input
volume just enough to prevent any further increase in dis­tortion. The Power Guard circuit acts so fast that there are
absolutely no audible side effects and the sonic purity of
the music reproduction is perfectly preserved. The MC207
Power Amplifier with Power Guard is not limited to just
the rated power output, but will actually produce distortion
free output well above its rated power due to the McIntosh
philosophy of conservative design.

Power Supply Circuits

To compliment the design of the MC207, there is a high
current power supply for the seven power amplifier chan­nels. Refer to figure 21. The very large Power Transfomer,
has toroidal windings on a toroidal core and can supply
over 35 amps of continuous current. Refer to figure 22
(golf ball is for size comparsion). It is enclosed in the leg­endary McIntosh Potted Enclosures and weighs over

Figure 22

12.06kg. The super size main filter capacitors can store
over 430 Joules of energy for the seven amplifier channels,
necessary for the wide dynamic range that “Digital Audio”
demands. Refer to figure 23. The power amplifier draws
high current from the AC power line. Therefore, it is im­portant that they plug directly into the wall outlet.

Also, most owners desire one power switch for the
whole audio system. The MC207 is equipped with a circuit
that provides remote Power Control from a McIntosh A/V

Block Diagram

of the

Power Supply

Figure 21

19

Figure 23

Control Center. When the A/V Control Center is switched
On a digital “1” (+5V) signal operates the power relay in
the MC207. The MC207 also has a remote Power Control
input for Zone B operation (two of the seven channels).

20

Notes

21

Specifications

Specifications

Power Output

Minimum sine wave continuous average power output per
channel, all channels operating is:
200 watts into a 4 ohm or 8 ohm load

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 or 8 ohm loads

Dynamic Headroom

1.7dB

Frequency Response

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

Sensitivity

1.0 Volt Balanced with a 4 ohm Loudspeaker

2.0 Volt Unbalanced with a 4 ohm Loudspeaker

1.4 Volt Balanced with a 8 ohm Loudspeaker

2.8 Volt Unbalanced with a 8 ohm Loudspeaker

Power Requirements

100 Volts, 50/60Hz at 14.4 amps
110 Volts, 50/60Hz at 13.0 amps
120 Volts, 50/60Hz at 12.0 amps
220 Volts, 50/60Hz at 6.0 amps
230 Volts, 50/60Hz at 6.0 amps
240 Volts, 50/60Hz at 6.0 amps

Note: Refer to the rear panel of the MC207 for the correct

voltage.

Overall Dimensions

17-1/2 inches (44.45cm) W, 9-7/16 inches (23.97cm) H,
18-3/4 inches (47.63cm) D, including clearance for con­nectors

Weight

83 pounds (37.6 kg) net, 116 pounds (52.6 kg) in shipping
carton

A-Weighted Signal To Noise Ratio

89dB (112dB below rated output)

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 or 8 ohm loads

Input Impedance

20,000 ohms Balanced
10,000 ohms Unbalanced

Wide Band Damping Factor

Greater than 60 at 4 ohms
Greater than 140 at 8 ohms

22

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. It is very important that the four plastic feet are at­tached to the bottom of the equipment. Four 1/4 - 20 x 2-1/
2 inch screws and washers must be used to fasten the unit
securely to the bottom pad and shipping skid. This will en­sure the proper equipment location on the bottom pad. Fail­ure to do this will result in shipping damage.

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 034052 Shipping carton top
1 034051 Shipping carton bottom
2 034054 Foam Pad (top and bottom)
2 034186 Foam Pad (front and rear)
2 034187 Foam Pad (sides)

1 034136 Inner carton top
1 034137 Inner carton bottom
1 034188 Foam Pad (inner carton)
1 034264 Shipping skid
4 101212 1/4 - 20x2-1/4 cap screw
4 104058 Flat washer

23

McIntosh Laboratory, Inc.

2 Chambers Street

Binghamton, NY 13903

The continuous improvement of its products is
the policy of McIntosh Laboratory Incorporated
who reserve the right to improve design without
notice.

Printed in the U.S.A.

McIntosh Part No. 04089600