Owner’s
Manual
MC126 Power Amplifier
MC126
McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903-2699 Phone: 607-723-3512 FAX: 607-724-0549
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.
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.
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. Caution: to prevent electrical shock do not use this
(polarized) plug with an extension cord, receptacle
or other outlet unless the blades can be fully inserted to prevent blade exposure.
Attention: pour pevenir les chocs elecriques pas
utiliser cette fiche polarisee avec un prolongateur,
une prise de courant ou un autre sortie de courant,
sauf si les lames peuvent etre inserees afond ans en
laisser aucune partie a decouvert.
7. Unplug this equipment during lightning storms or
when unused for long periods of time.
8. Only use attachments/accessories specified by the
manufacturer.
2
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.
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.
Installation:
9. The equipment shall be installed near the AC Socket
Outlet and the disconnect device shall be easily accessible.
10. Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
11. Do not install near any heat sources such as radiators,
heat registers, stoves, or other equipment (including
amplifiers) that produce heat.
12. Do not use this equipment near water.
13. 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.
14. Use only with the cart, stand, tripod,
bracket, or table specified by the manufacturer, or sold with the equipment.
When a cart is used, use caution when
moving the cart/equipment combination
to avoid injury from tip-over.
Connection:
15. Connect this equipment only to the type of AC power
source as marked on the unit.
16. Protect the power cord from being walked on or
pinched particularly at plugs, convenience receptacles,
and the point where they exit from the equipment.
17. 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.
18. Do not overload wall outlets, extension cords or integral convenience receptacles as this can result in a risk
of fire or electric shock.
19. To completely disconnect this equipment from the AC
Mains, disconnect the power supply cord plug from the
AC receptacle.
Care of Equipment:
20. Clean only with a dry cloth.
21. Do not permit objects or liquids of any kind to be
pushed, spilled and/or fall into the equipment through
enclosure openings.
22. Unplug the power cord from the AC power outlet
when left unused for a long period of time.
Repair of Equipment:
23. 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.
24. Do not attempt to service beyond that described in the
operating instructions. All other service should be referred to qualified service personnel.
25. 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.
26. 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.
Thank You
Your decision to own this McIntosh MC126 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: 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 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: 607-723-3515
Fax: 607-723-1917
Copyright 2001 ã by McIntosh Laboratory, Inc.
3
Introduction and Performance Features
Table of Contents
Safety Instructions ............................................................ 2
Thank You and Please Take a Moment............................. 3
Technical Assistance and Customer Service .................... 3
Table of Contents and General Notes ............................... 4
Introduction ...................................................................... 4
Performance Features ....................................................... 4
Dimensions ....................................................................... 5
Installation ........................................................................ 6
Rear Panel Connections and Switch ................................. 7
How to Connect for Six Channels .................................... 8
How to Connect for Three Channels .............................. 10
Front Panel Displays and Controls ................................. 12
How to Operate ............................................................... 13
Specifications ................................................................. 14
Packing Instruction ......................................................... 15
General Notes
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 MC126.
3. The MC126 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
MC126 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 MC126 over heats, 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 MC126 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 MX130/132 or C39 A/V Control
Center, Audio and Power Control connections, to the MC126.
If a McIntosh MSE1 Surround Expander is connected to the
MX130/132 or C39, then discrete Audio and Power Control
Cables should be used between them and the MC126. The
Diagram and Pin Identification list for the Multi-Channel
Input is as follows:
Multi-Channel Input
4
Multi-Channel Amp DB25 Connector Pin Layout
1. Left Front +
14. Left Front Gnd.
2. Center Front +
15. Center Front Gnd.
3. Right Front +
16. Right Front Gnd.
4. N/C
17. N/C
5. Left Surround +
18. Left Surround Gnd.
6. Right Surround +
19. Right Surround Gnd.
7. Left Back Surround + 20. Left Back Surround Gnd.
8. Right Back Surround + 21. Right Back Surround Gnd.
9. N/C
22. N/C
10. N/C
23. N/C
11. N/C
24. System Calibrate Gnd.
12. System Calibrate
25. Power Control Gnd.
13. Power Control In
Introduction
Now you can take advantage of traditional McIntosh standards of excellence in the MC126 Power Amplifier. Six
120 watt high current output channels will drive any high
quality loudspeaker system to its ultimate performance.
The MC126 reproduction is sonically transparent and absolutely accurate. The McIntosh Sound is “The Sound of the
Music Itself.”
Performance Features
·
Power Output
The MC126 consists of six separate power amplifier channels, each capable of 120 watts into 4 ohm speakers with
less than 0.005% distortion. It may also be used as a Three
Channel Amplifier with each channel capable of 275 watts
into 8 ohm speakers.
·
High Current Output
A peak output current of 10 amperes per channel ensures
that the MC126 will successfully drive high quality loudspeakers such as McIntosh for a truly exciting sound experience.
·
Power Guard
The MC126’s Patented McIntosh Power Guard Circuits
prevent each of the amplifier channels from being
overdriven 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 MC126 will have a long and trouble free
operating life. Built-in Thermal Protection Circuits guard
against overheating.
Dimensions
Dimensions
The following dimensions can assist in determining the
best location for your MC126. There is additional information on the next page pertaining to installing the MC126
into cabinets.
17-1/2"
44.45cm
Front View of the MC126
7 -5/8"
7 -1/8"
18.10cm
19.37cm
17"
43.18cm
Rear View of the MC126
6 -5/16"
16.03cm
13 -1/4"
33.66cm
18-1/2"
46.99cm
17"
43.18cm
Side View of the MC126
6-1/2"
3/16"
0.48cm
13/16"
2.06cm
16.51cm
14-1/16"
7/8"
35.72cm
2.22cm
5
Installation
Installation
The MC126 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 MC126 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 MC126 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 MC126 Front Panel
Custom Cabinet Cutout
are shown.
Always provide
adequate ventilation
for your MC126.
Cool operation ensures the longest
possible operating
life for any electronic instrument.
Cabinet
Front
Do not install the
Panel
MC126 directly
above a heat generating component
such as a high powered amplifier. If all
the components are MC126 Side View
installed in a single in Custom Cabinet
cabinet, a quiet running ventilation fan
can be a definite asSupport
Shelf
set in maintaining
all the system components at the
coolest possible operating temperature.
1-1/2"
A custom cabinet
MC126
Bottom
View
3.81cm
installation should
in Custom Cabinet
provide the following minimum spacing dimensions for
cool operation. Allow at least 6 inches
(15.24 cm) above the top, 2 inches (3.81cm) below the bottom and 1 inch (2.54 cm) on each side of the amplifier, so
that airflow is not obstructed. Allow 20 inches (50.8 cm)
depth behind the front panel. Allow 1 inch (2.54 cm) 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
6 -5/8"
16.83cm
Cutout Opening for Custom Mounting
Cutout Opening for Ventilation
6"
Spacers
15.24cm
9-1/2"
24.13cm
Cutout
Opening
14"
35.56cm
for
Ventilation
14-1/16"
35.72cm
6
Chassis
13-3/16"
33.50cm
Rear Panel Connections and Switch
INPUTS for discrete audio
cables from an A/V Control
Center or Preamplifier Audio
Outputs
Selects power
turn-on mode
MULTI-CHANNEL INPUT
accepts a 25 conductor DB25
computer type cable that connects all audio and power control signals
Individual Input
LEVEL Controls
for each channel
Main Fuse holder, refer
to information on the
back panel of your
MC126 to determine the
correct fuse size and rating
POWER CONTROL IN receives turn
On/Off signals from a McIntosh component and the POWER CONTROL OUT
sends that turn On/Off signal to the next
McIntosh component
MODE switch selects
between Stereo and Mono
Bridge operation for each
pair of channels
Connect the MC126
power cord to a live
AC outlet. Refer to
information on the
back panel to determine the correct voltage
Loudspeaker OUPUT Connections for
Stereo and Mono Bridge Modes of
Operation for each pair of channels
7
How to Connect the MC126 for Six Channels
Caution: The supplied AC Power Cord should not be
connected to the Rear Panel of the MC126
Amplifier until after the Loudspeaker Connections
have been made and the supplied protective
Terminal Connection Covers have been installed.
Failure to observe this could result in Electric
Shock.
1. Connect a power control cable from the McIntosh A/V
Control Center Power Control Out to the McIntosh
Surround Expander Power Control In.
2. Connect a power control cable from the McIntosh Surround Expander Power Control Out to the MC126
POWER CONTROL IN.
3. Connect cables from the Audio Outputs of a McIntosh
A/V Control Center and Surround Expander to the
MC126 INPUTS, making sure to match up the channel
identifications between both units.
4. Prepare the Loudspeaker Hookup Cables that attach to
the MC126 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:
Insert the banana plug into the hole at the top of the
terminal. Tighten the top portion of the terminal post
and the set screw to secure the banana plug in place.
Note: The use of Banana Plugs is for use in the United
States and Canada only.
5. Connect the Loudspeaker Hookup Cables from the
MC126 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.
6. Attach each of the three supplied Terminal Connection
Covers with the four Pan Head
Mounting Screws (6-32 x 5/16
inch) to the Rear Panel of the
MC126 Amplifier. Refer to figures 7 and 8.
Note: There are four openings on the bottom edge of the
cover to allow the Loudspeaker Cables to exit the
MC126.
7. Connect the MC126 Power Cord to an active AC outlet.
Figure 8
Terminal
Connection Cover
8
Figure 7
Cable
Opening
How to Connect the MC126 for Six Channels
McIntosh A/V Control Center
McIntosh Surround Expander
To AC
Outlet
Center Front
Loudspeaker
Right Front
Loudspeaker
Left Front
Loudspeaker
Back Surround
Loudspeaker
Right Surround
Loudspeaker
Left Surround
Loudspeaker
9
How to Connect the MC126 for Three
Channels
Caution: The supplied AC Power Cord should not be
connected to the Rear Panel of the MC126
Amplifier until after the Loudspeaker Connections
have been made and the supplied protective
Terminal Connection Covers have been installed.
Failure to observe this could result in Electric
Shock.
1. Connect a power control cable from the McIntosh A/V
Control Center Power Control Out to the McIntosh
MC126 POWER CONTROL IN.
2. Connect cables from the Audio Outputs of a McIntosh
A/V Control Center to the MC126 MONO INPUTS.
3. Prepare the Loudspeaker Hookup Cables that attach to
the MC126 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:
Insert the banana plug into the hole at the top of the
terminal. Tighten the top portion of the terminal post
and the set screw to secure the banana plug in place.
Note: The use of Banana Plugs s for use in the United
States and Canada only.
5. Connect the Loudspeaker Hookup Cables from the
MC126 MONO 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.
6. Attach each of the three supplied Terminal Connection
Covers with the four Pan Head
Mounting Screws (6-32 x 5/16
inch) to the Rear Panel of the
MC126 Amplifier. Refer to figures 7 and 8.
Note: There are four openings
on the bottom edge of the
Figure 7
cover to allow the
Loudspeaker Cables to exit the MC126.
7. Connect the MC126 Power Cord to an active AC outlet.
Figure 8
Terminal
Connection Cover
10
Cable
Opening
How to Connect the MC126 for Three Channels
McIntosh A/V Control Center
To AC
Outlet
Center Front
Loudspeaker
(8 ohm)
Right Front
Loudspeaker
(8 ohm)
Left Front
Loudspeaker
(8 ohm)
11
Front Panel Displays and Controls
POWER GUARD LEDs light
when the LEFT FRONT, CENTER or RIGHT FRONT Amplifier
Channel POWER GUARD Circuit
activates
Remote On Indicator
lights when the amplifier
is in the Remote Turn-On
Mode
POWER GUARD LEDs light when
the LEFT SURRound, BACK
SURRound or RIGHT SURRound
Amplifier Channel POWER
GUARD Circuit activates
12
POWER Switch
Turns AC power
On/Off
How to Operate the MC126
How to Operate the MC126
How to Operate with a Bridged Channel
Power On
To have the MC126 turn On or Off when a multichannel
system turns On or Off, the Front Panel Power Switch must
be left in the ON position and the
Rear Panel Power Control Switch
must be in the REMOTE Position. For
non-remote operation, set the Rear
Panel Power Control Switch to LOCAL and use the Front Panel Power
Switch to turn the MC126 On or Off
Figure 9
as desired. Refer to figure 9.
The versatile McIntosh MC126 can be used in two different Operating Modes. The three channel pairs can be used
in Stereo Mode to supply 120 watts (4 ohm) to each of the
Home Theater System’s six channels. Any of the three stereo pairs can be set to Mono (Bridged) Mode to supply 275
watts (8ohm) of power when greater power is desired. Refer to figures 10, 11 and 12.
Note: There must be a power control
connection between the MC126 and the McIntosh A/V
Control Center or Surround Decoder in order for the
remote power turn-on to function.
Input Level Controls
When using a McIntosh A/V Control Control Center or
Surround Decoder set all six level controls to the 1.6V position. If an A/V
Control Center or Surround Decoder has
a 0.8V output rating, set the controls to
the 0.8V position. If an increase or deFigure 10
crease in amplifier sensitivity is required
for other applications, set the controls as desired. Refer to
figure 10.
1. Set the MODE Switch to the
MONO position.
2. Adjust the MONO Level control
Figure 12
to the 1.6V position if using a
McIntosh A/V Control Center or Surround Decoder.
3. Connect the cable from the signal source component to
the MONO In jack.
4. Connect loudspeaker cables to the terminals marked (-)
and (+) MONO.
Mode Switch
The MODE Switch allows a pair of MC126 channels to be
used in two different operating configurations. Refer to figure 11.
Stereo: Each channel operates indepenFigure 11
dently as 120 watt amplifiers.
Mono: A channel pair operates in bridged configuration for a single monaural 275 watt amplifier.
13
Specifications
Specifications
Power Output Stereo
Minimum sine wave continuous average power output per
channel, all channels operating is:
120 watts into a 4 ohm load
80 watts into a 8 ohm load
Power Output Mono
Minimum sine wave continuous average power output per
channel, all channels operating is:
275 watts into a 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 (Stereo)
0.005% for 8 ohm loads (Mono)
Dynamic Headroom
1.8dB
Frequency Response
+0, -0.25dB from 20Hz to 20,000Hz
+0, -3dB from 10Hz to 100,000Hz
Sensitivity
0.8Volts
A-Weighted Signal To Noise Ratio
92dB (113dB 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 (Stereo)
0.005% for 8 ohm loads (Mono)
Input Impedance
20,000 ohms
Wide Band Damping Factor
100 at 4 ohms
200 at 8 ohms
14
Power Requirements
100 Volts, 50/60Hz at 9.4 amps
110 Volts, 50/60Hz at 8.5 amps
120 Volts, 50/60Hz at 5.9 amps
220 Volts, 50/60Hz at 4.3 amps
230 Volts, 50/60Hz at 4.0 amps
240 Volts, 50/60Hz at 3.9 amps
Note: Refer to the rear panel of the MC126 for the correct
voltage.
Dimensions
Front Panel: 17-1/2 inches (44.45cm) wide, 7-1/8 inches
(18.10cm) high. Depth behind front mounting panel is 18
inches (45.72cm). Clearance required in front of the Front
Panel is 1 inch (2.54cm) for knobs.
Weight
58 pounds (26.3 kg) net, 77 pounds (34.9 kg) in shipping
carton
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 three plastic feet are attached to the bottom of the equipment. Three #10 x 2-1/2
inch screws and washers must be used to fasten the unit
securely to the bottom pad and wood 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
1
4
Part Number
033888
033887
Description
Shipping carton only
End cap (Foam pad)
1
1
1
3
1
3
3
033697
033725
034008
017218
033699
101169
104033
Inside carton only
Top Pad
Bottom pad
Plastic foot (spacer)
Shipping skid
#10 x 2-1/2 inch Wood screw
#10 x 1-3/4 inch Flat washer
4
4
017218
100159
4
104083
Plastic foot
#10-32 x 3/4 inch Machine
screw
#10 x 7/16 inch Flat washer
15
McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, NY 13903
McIntosh Part No. 040650