Mcintosh ma6900om04 schematic

Integrated Amplifier

MA6900

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

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.

the apparatus.

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 tip­over.

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 You

Table of Contents

Your decision to own this McIntosh MA6900 Integrated
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:

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

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

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

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

Important Information ...................................................... 4

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

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

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

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

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

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

How to Connect for Loudspeakers ................................... 8

How to Connect for Audio and Data Control ................... 9

How to Connect for Video .............................................. 10

How to Connect for a Second Room .............................. 11

Front Panel Controls, Display, Indicator Push-Button

and Switch ...................................................................... 12

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

Remote Control Push-Buttons ........................................ 16

How to Operate by Remote Control ............................... 17

Technical Description ..................................................... 18

Specifications ................................................................. 22

Packing Instruction ......................................................... 23

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]

Copyright 2004 © by McIntosh Laboratory, Inc.

3

Introduction and Performance Features

Important Information

1. The following parts are 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.

Jumper Plugs Part No. 117-781

RCA Phono Jumpers, 14mm center spacing.

2. For additional connection information, refer to the owner’s
manual(s) for any component(s) connected to the MA6900.

3. The MA6900 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:

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 MA6900 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 MA6900 has returned to a safe operating
temperature, normal operation will resume.

Connector Information

XLR Connectors

Below is the Pin configuration for the XLR Balanced Input
Connectors on the MA6900. Refer to the diagram for con­nection:

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

Pin 2

Pin 1

Pin 3

Introduction

Now you can take advantage of traditional McIntosh stan­dards of excellence in the MA6900 Integrated Amplifier.
Two 200 watt high current output channels will drive any
high quality loudspeaker system to its ultimate perfor­mance and the flexible Preamplifier Selection provides for
hookup and control of various input sources. The MA6900
reproduction is sonically transparent and absolutely accu­rate. The McIntosh Sound is “The Sound of the Music It­self.”

Performance Features

••

• Power Output

••

The MA6900 consists of two separate power amplifier
channels, each capable of 200 watts into 2, 4 or 8 ohm
speakers with less than 0.005% distortion.

••

• Electronic Input Switching

••

Digital Logic integrated circuits drive Electromagnetic
Switches on all six inputs and operating functions for reli­able, noiseless, distortion free switching.

••

• Power Guard

••

Both 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.

••

• Sentry Monitor and Thermal Protection

••

McIntosh Sentry Monitor power output stage protection
circuits ensure the MA6900 will have a long and trouble
free operating life. Built-in Thermal Protection Circuits
guard against overheating.

Power Control and Trigger Connectors

The MA6900’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.

Data Port Connector

The MA6900’s Data Port Output provides Remote Control
Signals. Use a 1/8 inch stereo
mini phone plug to connect to the
Data Port Inputs on McIntosh
Source Units.

4

Positive

N/C

Ground

Data Signal

N/C

Ground

••

• Patented Autoformers

••

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.

••

• Illuminated Power Meters

••

The Illuminated Power Output Meters on the MA6900 are
peak responding, and indicate the power output of the am­plifier.

MA6900 Dimensions

The following dimensions can assist in determining the
best location for your MA6900. There is additional infor­mation on the next page pertaining to installing the
MA6900 into cabinets.

17-

1/2

44.45cm

MA6900 Dimensions

"

Front View of the MA6900

Rear View of the MA6900

16-

1/16

40.8cm

12-

3/16

30.96cm

7 -

5/8

7 -

1/8

"

18.10cm

19.37cm

"

"

6"

15.24cm

"

Side View of the MA6900

13/16

2.06cm

18-

3/4

"

47.63cm

16-

1/2

"

41.91cm

6-

1/4

3/16

"

0.48cm

"

13"

33.02cm

1"

2.54cm

"

15.88cm

5

Installation

Installation

The MA6900 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 MA6900 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 MA6900 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 MA6900.
Cool operation en­sures the longest
possible operating
life for any elec­tronic instrument. Do

MA6900 Front Panel
Custom Cabinet Cutout

not install the
MA6900 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 as-

Cabinet
Front
Panel

Opening
for Ventilation

set in maintaining all
the system compo­nents at the coolest
possible operating
temperature.

MA6900 Side View
in Custom Cabinet

A custom cabinet
installation should
provide the follow­ing minimum spac-

Support
Shelf

ing dimensions for
cool operation. Al­low at least 6 inches
(15.24cm) above the
top, 2 inches
(3.81cm) below the

MA6900 Bottom View
in Custom Cabinet

2"

5.08cm

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

6 -

5/8

"

16.83cm

6"

15.24cm

1"

2.54cm

14-

36.83cm

Cutout

Opening

for

Ventilation

Cutout Opening for Custom Mounting

Cutout Opening for Ventilation

1/2

"

13"

33.02cm

Chassis
Spacers

10-

3/8

26.35cm

"

14-

1/8

35.88cm

"

13"

33.02cm

6

MA6900 Rear Panel Connections and Switch

Main Fuse holder,
refer to information
on the back panel
of your MA6900 to
determine the cor­rect fuse size and
rating

The EXT
(external)
SENSOR(s)
for a Keypad
or IR Sensor

Right OUTPUT
Connections for
2, 4 or 8 ohm
loudspeakers

POWER CONTROL 1 and 2
Outputs send a turn-on signal
to an external McIntosh
Power Amplifier when the
MA6900 Front Panel Output
1 and/or 2 is On

CD1 balanced INPUTS
accept high level program
source signals

OUTPUTS 1
and 2 supply
the Preamplifier
Output to either
the internal or
external power
amplifier

TAPE OUTPUTS
provide the Record
Out Signal

VIDEO inputs
for audio signals
from a LV, VCR,
TV or an A/V
Selector

Left OUTPUT
Connections for
2, 4 or 8 ohm
loudspeakers

GND terminal
accepts a
ground wire
from a turn­table

POWER CONTROL
MAIN Output sends
a turn-on signal to an
external McIntosh
Power Amplifier
when the MA6900 is
turned on

Connect the
MA6900 power
cord to a live AC
outlet. Refer to in­formation on the
back panel to deter­mine the correct
voltage

DATA PORTS send
signals to McIntosh
Compatible Compo­nents to allow control
with the remote con­trol

POWER CONTROL
ACC Output sends a
turn-on signal to a
McIntosh Source
Component or Power
Control unit when the
MA6900 is turned on

JUMPER PLUGS
connect the Pream­plifier OUTPUT 1
Jacks to the POWER
AMP IN Jacks and
are needed for nor­mal operation

POWER AMP IN
inputs accept sig­nals from a sepa­rate external
preamplifier

TUNER and
CD2 inputs ac­cept signals
from the output
of a tuner and
CD player

TAPE input
accepts signals
from the out­put of a tape
deck

AUX accepts high level program
source signals, PH accepts signals
from a Moving Magnet phono car­tridge, and the small slide switch
selects which one of these two in­puts is active when the front panel
PH/AUX Push-button is pressed

7

How to Connect Loudspeakers

Caution: The supplied AC Power Cord should not be

connected to the Rear Panel of the MA6900
Amplifier until after the Loudspeaker Connections
have been made. Failure to observe this could
result in Electric Shock.

1. Prepare the Loudspeaker Hookup Cables that attach to
the 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.

How to Connect Loudspeakers

Banana plug connection:
Insert the banana plug into the hole at the top of the
terminal.

Note: Banana Plugs are for use in the United States and

Canada only.

2. Connect the loudspeaker hookup cables to the output
terminals that match the impedance of your loudspeak­ers, being careful to observe the correct polarities. Out­put impedance connections of 2 ohms, 4 ohms and 8
ohms are provided. If the impedance of your loud­speakers is in-between the available connections, use
the nearest lower impedance connection.

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.

Right
Loudspeaker
4 ohm

8

Left
Loudspeaker
4 ohm