McIntosh MA6900 User manual

McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 139 3-2699 Phone: [phone] FAX: [phone]
Owners
Manual
MA6900
MA6900 Integrated Amplifier

2
IMPORTANT SAFETY
INSTRUCTIONS!
PLEASE READ THEM BEFORE
OPERATING THIS EQUIPMENT.
WARNING - TO REDUCE RISK OF
FIRE OR ELECTRICAL SHOCK, DO
NOT EXPOSE THIS EQUIPMENT TO
RAIN OR MOISTURE.
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.
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 e clamation point within an equi-
lateral triangle is intended to alert the
user to the presence of important
operating and maintenance (servic-
ing) instructions in the literature ac-
companying the appliance.
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 pres-
sure levels. ontinued exposure to high sound pres-
sure levels can cause permanent hearing impair-
ment or loss. User caution is advised and ear protec-
tion is recommended when playing at high volumes.
6. aution: to prevent electrical shock do not use this
(polarized) plug with an extension cord, receptacle
or other outlet unless the blades can be fully in-
serted 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.
. Only use attachments/accessories specified by the
manufacturer.
Installation:
9. The equipment shall be installed near the AC Socket
Outlet and the disconnect device shall be easily acces-
sible.
10. Do not block any ventilation openings. Install in accor-
dance 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 manu-
facturer, or sold with the equipment.
When a cart is used, use caution when
moving the cart/equipment combination
to avoid injury from tip-over.
onnection:
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.

3
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.
1 . Do not overload wall outlets, extension cords or inte-
gral 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.
are 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. Ser-
vicing is required when the equipment has been dam-
aged 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 re-
ferred to qualified service personnel.
25. When replacement parts are required, be sure the ser-
vice technician has used replacement parts specified by
McIntosh or have the same characteristics as the origi-
nal part. Unauthorized substitutions may result in fire,
electric shock, or other hazards.
26. Upon completion of any service or repairs to this prod-
uct, ask the service technician to perform safety checks
to determine that the product is in proper operating
condition.
Customer Service
Technical Assistance
Please Take A Moment
Thank You
Copyright 2001 ã by McIntosh Laboratory, Inc.
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:
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.
Serial Number:
Purchase Date:
Dealer Name:
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 as-
sistance 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]
If at any time you have questions about your McIntosh
product, contact your McIntosh dealer who is familiar with
your McIntosh equipment and any other brands that may
be part of your system. If you or your dealer wish addi-
tional help concerning a suspected problem, you can re-
ceive technical assistance for all McIntosh products at:
McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, New York 13903
Phone: [phone]
Fax: [phone]

4
Performance eatures
Introduction and Performance eatures
Introduction
·Power Output
The MA6900 consists of two separate power amplifier
channels, each capable of 200 watts into 2, 4 or 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 reli-
able, 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.
·Patented Autoformers
McIntosh designed and manufactured Output Autoformers
provide an ideal match between the amplifier output stages
and speaker loads of 2, 4 and ohms. The Autoformers
also provide perfect DC protection for your valuable loud-
speakers.
·Illuminated Power Meters
The Illuminated Power Output Meters on the MA6900 are
peak responding, and indicate the power output of the am-
plifier.
Now you can take advantage of traditional McIntosh stan-
dards of excellence in the MA6900 Integrated Amplifier.
Two 200 watt high current output channels will drive any
high quality loudspeaker system to its ultimate perfor-
mance and the flexible Preamplifier Selection provides for
hookup and control of various input sources. The MA6900
reproduction is sonically transparent and absolutely accu-
rate. The McIntosh Sound is The Sound of the Music It-
self.
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 Loudspeakers ...................................
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 ..................................................... 1
Specifications ................................................................. 22
Packing Instruction ......................................................... 23
General Notes
1. The following parts are available from the McIntosh Parts
Department:
Power Control Cable Part No. 170-202
Six foot, 2 con uctor shiel e , with two 1/8 inch stereo
mini phone plugs.
Jumper Plugs Part No. 117-781
RCA Phono Jumpers, 14mm center spacing.
2. For a itional connection information, refer to the owners
manual(s) for any component(s) connecte to the MA6900.
3. The MA6900 mutes the speaker outputs for approximately two
secon s when first turne on.
4. It is very important that lou speaker cables of a equate size
be use , so that there will be no power loss. The size is
specifie in Gauge Numbers or AWG (American Wire Gauge).
The smaller the Gauge number, the larger the wire size:
If your lou speaker cables are 50 feet (38.1m) or less,
use at least 14 Gauge.
If your lou speaker cables are 100 feet (76.2m) or less,
use at least 12 Gauge.
5. Pin configuration for the XLR Balance Input connectors on
the MA6900: PIN 1: Shiel or groun
PIN 2: + input
PIN 3: - input
6. In the event that the MA6900 over heats, ue to improper
ventilation an /or high ambient temperature, the protection
circuits will activate. The Front Panel Power Guar LEDs
will continuously in icate ON an the au io will be mute .
When the MA6900 has returne to a safe operating
temperature, normal operation will resume.

5
MA6900 Dimensions
The following dimensions can assist in determining the
best location for your MA6900. There is additional infor-
mation on the next page pertaining to installing the
MA6900 into cabinets.
MA6900 Dimensions
17-1/2"
44.45cm
7 -5/8"
19.37cm
3/16"
0.48cm
16-1/16"
40.8cm
Front View of the MA6900
Rear View of the MA6900
Side View of the MA6900
7 -1/8"
18.10cm
13/16"
2.06cm
6"
15.24cm
12-3/16"
30.96cm
18-3/4"
47.63cm
16-1/2"
41.91cm
6-1/4"
15.88cm
1"
2.54cm
13"
33.02cm

6
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 to-
gether 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 en-
sures the longest
possible operating
life for any elec-
tronic instrument. Do
not install the
MA6900 directly
above a heat generat-
ing component such
as a high powered
amplifier. If all the
components are in-
stalled in a single
cabinet, a quiet run-
ning ventilation fan
can be a definite as-
set in maintaining all
the system compo-
nents at the coolest
possible operating
temperature.
A custom cabinet
installation should
provide the follow-
ing minimum spac-
ing dimensions for
cool operation. Al-
low at least 6 inches
(15.24cm) above the
top, 2 inches
(3. 1cm) below the
bottom and 1 inch
Installation
6- 5/8 "
16.83cm
17- 1/16 "
43.34cm
Cutout Opening for Custom Mounting
MA6900 Front Panel
Custom Cabinet Cutout
Cutout
Opening
for
Ventilation
Cutout Opening for Ventilation
Support
Shelf
Cabinet
Front
Panel
Chassis
Spacers
MA6900 Side View
in Custom Cabinet
MA6900 Bottom View
in Custom Cabinet
14- 1/2 "
36.83cm
1"
2.54cm
6"
15.24cm
Opening
for Ventilation
10- 3/8 "
26.35cm
13"
33.02cm
13"
33.02cm
14- 1/8 "
35.88cm
2"
5.08cm
(2.54cm) on each side of the amplifier, so that airflow is
not obstructed. Allow 20 inches (50. cm) 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.

7
MA6900 Rear Panel Connections and Switch
Main Fuse holder,
refer to information
on the back panel
of your MA6900 to
determine the cor-
rect fuse size and
rating
Right UTPUT
Connections for
2, 4 or 8 ohm
loudspeakers
Left UTPUT
Connections for
2, 4 or 8 ohm
loudspeakers
The EXT
(external)
SENS R(s)
for a Keypad
or IR Sensor
TAPE input
accepts signals
from the out-
put of a tape
deck
GND terminal
accepts a
ground wire
from a turn-
table
VIDE inputs
for audio signals
from a LV, VCR,
TV or an A/V
Selector
P WER C NTR L
MAIN utput sends
a turn-on signal to an
external McIntosh
Power Amplifier
when the MA6900 is
turned on
P WER C NTR L 1 and 2
utputs send a turn-on signal
to an external McIntosh
Power Amplifier when the
MA6900 Front Panel utput
1 and/or 2 is n
P WER C NTR L
ACC utput sends a
turn-on signal to a
McIntosh Source
Component or Power
Control unit when the
MA6900 is turned on
DATA P RTS send
signals to McIntosh
Compatible Compo-
nents to allow control
with the remote con-
trol
Connect the
MA6900 power
cord to a live AC
outlet. Refer to in-
formation on the
back panel to deter-
mine the correct
voltage
CD1 balanced INPUTS
accept high level program
source signals
UTPUTS 1
and 2 supply
the Preamplifier
utput to either
the internal or
external power
amplifier
P WER AMP IN
inputs accept sig-
nals from a sepa-
rate external
preamplifier
JUMPER PLUGS
connect the Pream-
plifier UTPUT 1
Jacks to the P WER
AMP IN Jacks and
are needed for nor-
mal operation
TAPE UTPUTS
provide the Record
ut Signal
AUX accepts high level program
source signals, PH accepts signals
from a Moving Magnet phono car-
tridge, and the small slide switch
selects which one of these two in-
puts is active when the front panel
PH/AUX Push-button is pressed
TUNER and
CD2 inputs ac-
cept signals
from the output
of a tuner and
CD player

8
How to Connect Loudspeakers
Caution: The supplied C Power Cord should not be
connected to the Rear Panel of the M 6900
mplifier 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 to-
gether as tightly
as possible.
Note: If esire ,
the twiste
en s can be tinne with sol er to keep the stran s
together, or attach spa e lug an /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.
Note: Banana Plugs are for use in the Unite States an
Cana a only.
2. Connect the loudspeaker hookup cables to the output
terminals that match the impedance of your loudspeak-
ers, being careful to observe the correct polarities. Out-
put impedance connections of 2 ohms, 4 ohms and
ohms are provided. If the impedance of your loud-
speakers is in-between the available connections, use
the nearest lower impedance connection.
W RNING: 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
Left
Loudspeaker
4 ohm
How to Connect Loudspeakers

9
How to Connect Audio Components
1. Connect an Audio Cable from the McIntosh CD Player
Audio Outputs to the MA6900 CD2 INPUTS.
2. Connect an Audio Cable from a McIntosh Tuner 1 Out-
puts to the MA6900 TUNER INPUTS.
3. Connect an Audio Cable from a Turntable to the
PH/AUX INPUTS and the Turntable Ground Connec-
tion to the GND grounding post.
4. Connect an Audio Cable from the MA6900 TAPE
OUTPUTS to the Record Inputs of a Tape Recorder
and from the MA6900 TAPE INPUTS to a Tape Re-
corder Outputs.
5. Connect a Control Cable from the MA6900 POWER
CONTROL ACC Jack to the Power Control In on the
McIntosh Tuner.
6. Connect a Control Cable from the McIntosh Tuner
Power Control Out Jack to the Power Control In jack
on the McIntosh CD Player.
7. Connect a Control Cable from the MA6900 TUNER
DATA PORT Jack to the McIntosh Tuner Data In
(Tuner 1).
. Connect a Control Cable from the MA6900 CD2
DATA PORT Jack to the McIntosh CD Player Data In
Jack.
9. Connect the MA6900 Power Cord to a live AC outlet.
To AC Outlet
Tape Recorder Turntable
McIntosh CD Player
McIntosh Tuner
How to Connect Audio Components
Out
In

1
How to Connect for Video Switching
How to Connect for Video Switching
1. Connect a Data cable from the MA6900 VIDEO DATA
PORT to the Audio/Video Selector Data In jack.
2. Connect the Audio/Video Selector Control Center Au-
dio Outputs to the MA6900 VIDEO INPUTS.
3. Connect the Audio/Video Selector Video Monitor Out-
put to a Monitor/TV.
Note: Either or both Au io/Vi eo Selector Monitor
Output(s) may be connecte to the Monitor/TV.
4. Connect a McIntosh DVD/CD Player Audio Outputs to
the Audio/Video Selector V-Aux Audio Inputs, the
Video Output to the Audio/Video Selector Video Input
and the Control Out to the Audio/Video Selector Data
Output jack.
5. Connect a Control Cable from the MA6900 POWER
CONTROL ACC Jack to the Power Control In on the
McIntosh DVD/CD Player.
6. Connect other video source components to the appro-
priate audio and video and data jacks on the Audio/
Video Selector.
McIntosh DVD Player
Audio/Video Selector
Monitor/TV

11
How to Connect for a Second Room
How to Connect for a Second Room
1. Connect Audio Cables from the MA6900 OUTPUTS 2
to the Second Power Amplifier Inputs.
2. Connect Hookup Cables from the Second Power Am-
plifier to the loudspeakers. Refer to page in this
Owners Manual for connection details.
3. Connect a Control Cable from the MA6900 POWER
CONTROL 2 Jack to the Power Control In of a McIn-
tosh Power Amplifier.
4. Connect an RG6 or RG59U coaxial cable from the
EXTernal SENSOR Jack to a Keypad.
Note: A Wall Mounte IR Sensor may also be use in place
of the keypa .
Right
Loudspeaker
4 ohm
Left
Loudspeaker
4 ohm
McIntosh Power Amplifier
Keypad

12
ront Panel Controls, Push-Buttons and Switch
P WER
switch turns
all AC power
completely
N or FF
M N push-button
combines the left and
right channel signals for
Mono operation
V LUME control
allows adjustment of
the listening level for
both channels
The BALANCE control
allows adjustment of
the relative volume bal-
ance between channels
MUTE push-button
mutes the listening
audio
STANDBY/ N
push-button turns
the MA6900 N,
or FF (Standby)
IR Sensor
receives
commands
from a re-
mote con-
trol
HEADPHONES jack
allows connection of
Stereo Headphones for
private listening
METER indicates the
Left Channel Power
utput of the amplifier
P WER GUARD
LEDs light when the
amplifiers channel
P WER GUARD
circuit activates
METER indicates the
Right Channel Power
utput of the amplifier
L UDNESS
provides fre-
quency re-
sponse con-
toured to com-
pensate for the
behavior of the
human ear at
softer listening
levels
UTPUTS 1
and 2 push-
buttons turn the
Speakers and
Preamplifier
utputs n or
ff
Select any one
of the six Audio
signal sources
Equalizer provides
12dB of boost or cut
at the center frequen-
cies indicated above
each control

13
How to Operate
How to Operate
Power On
Press the POWER switch to ON. The Red LED above the
STANDBY/ON push-button, lights to
indicate the MA6900 is in Standby
mode. To turn On the MA6900, press
the STANDBY/ON push-button. The
MUTE LED will light for approxi-
mately two seconds after turn on. Re-
fer to figures 1 and 2.
Note: For normal
operation, turn the
MA6900 On an
Off with the
Stan by/On push-
button. If the
amplifier is not
going to be use for
an exten e time,
turn off all AC
Power with the
Power Switch. You
may also turn On
the MA6900 by
simply pressing the
esire Source
Selection Push-
button on the Front
Panel or Remote
Control.
Source Selection
Select the desired source
with the appropriate push-
button switch on the Front
Panel or Remote Control.
Refer to figures 2 and 3
and page 16 for additional
information.
Volume ontrol
Adjust the VOLUME con-
trol for the desired listen-
ing level.
PH/AUX Inputs
When using a phono player with a moving magnet car-
tridge connected to the PH/AUX inputs,
set the PH AUX switch to the PH posi-
tion. When using an auxiliary program
source component connected to the PH/
AUX inputs, set the PH AUX switch to
the AUX position. Refer to figure 4.
Balance ontrol
Adjust the BALANCE control as needed to achieve ap-
proximately equal listening volume levels in each loud-
speaker. Turn the BALANCE to the left to emphasize the
Left Channel by reducing the level of the Right Channel.
Turn the BALANCE to the right to emphasize the Right
Channel by reducing the level of the Left Channel.
Equalizer ontrols
Each of the five Equalizer Frequency Controls will raise or
lower by approximately12dB, the amplitude of the band of
frequencies centered at the frequency marked above the
controls. Both Left and Right Channels are affected. Refer
to figure 5. At the center detent or flat position of the con-
trols, all equalizer circuit components are removed from
the signal path.
Loud Switch
Press the LOUD push-button to add loudness bass compen-
sation to the volume control for improved low level listen-
ing.
Mono
Press the MONO push-button to combine left and right ste-
reo signals to mono at the SPEAKERS 1 and 2 and HEAD-
PHONES output.
Mute
Press the MUTE push-button to mute audio in all outputs
except the HEADPHONES and TAPE OUTPUT. The
MUTE LED above the push-button will flash on and off to
indicate that Mute is active. To unmute audio, press
MUTE, press the Remote Control Volume push-button(s)
or press an Input push-button.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5

14
How to Operate, cont
Outputs 1 and 2
Press OUTPUTS Push-button 1 to switch the Speakers On
or Off. The
push-buttons
also switch the
Preamplifier
OUTPUTS 1
and 2 On or Off
for connection to external Power Amplifier(s). Press either
push-button individually, or both together. Refer to figure
6.
Headphones Jack
Connect a pair of dynamic headphones to the Headphones
Jack for private listening. Press Mute to mute all other out-
puts including the amplifier connected to the loudspeakers.
Refer to figure 6.
Reset of Microprocessors
In the event that the controls of the MA6900 stop function-
ing, push the POWER switch OFF and wait about two min-
utes. Then push the POWER switch ON followed by push-
ing the STANDBY/ON push-button. This will reset the
MA6900 microprocessors and the Integrated Amplifier
should be functioning normally.
Note: The above con ition is usually cause by either
interruptions in AC power an /or major changes that
may occur in AC power line voltage.
Using a Separate Power Amplifier
There are two different ways to use a separate power am-
plifier with a MA6900. The first way
is to use the separate amplifier instead
of the MA6900 built-in Power Ampli-
fier. Connect the loudspeakers to the
separate power amplifier and remove
the McIntosh Jumpers that are located
between the OUTPUTS 1 Jacks and
the POWER AMP INput Jacks. Refer to figures 7 and .
Note: The McIntosh Jumpers must be connecte , between the
above mentione jacks, when the MA6900 Internal
Power Amplifier is to be use .
The second way is to use both a sepa-
rate power amplifier and the MA6900
built-in Power Amplifier. Connect one
pair of loudspeakers to the separate
power amplifier and the second pair to
the MA6900.
Note: The MA6900 VOLUME Control will affect the soun
level of all the lou speakers.
How To Make A Tape Recording
1. Select the source signal you wish to record with the
appropriate Front Panel input push-button. If you wish
to record from an Audio/Video source connected to the
optional McIntosh Audio/Video Selector Audio/Video
Selector, using the Remote Control, select the desired
source connected to the McIntosh Audio/Video Selec-
tor. Refer to figure 9.
2. Adjust the record level using the tape recorder volume
control and proceed with the recording process.
3. To listen to the tape playback of the program source
just recorded, press the TAPE input push-button.
Note: The MA6900 TAPE OUTPUTS are not affecte by the
VOLUME or BALANCE controls.
Power Output Meters
The MA6900 Power Output Meters indicate the power de-
livered to the 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.
Figure 6
No Jumpers
Figure 8
Jumpers
Figure 7
Figure 9

15
Notes

16
Remote Control Push-Buttons
Selects one of the twelve
High Level Audio/Video
Sources or Phono Input
Turns AC Power N or FF to
certain McIntosh Components
when connected via the Data Port
Adjusts the volume
level up or down
Selects CD Player or
Tape Recorder Functions
and also performs various
functions on a variety of
McIntosh Components
Press to Power the MA6900
N or FF
Use to select tuner
presets, disc tracks or
any numbered opera-
tion
Selects Switched utput
2, FM Tuner perating
Functions and Track Se-
lection on certain McIn-
tosh CD Players
Mutes the audio
Note: The Remote Control push-buttons that
are blackene out are for use with
other McIntosh Pro ucts.
Press M DE to switch
between Stereo or Mono
Modes
Selects Switched utput
1, AM Tuner perating
Functions and Disc Selec-
tion on certain McIntosh
CD Players
Selects n Screen Func-
tions for McIntosh DVD
Players and certain CD
Players
Press TRIM to turn the
Loudness Control n or
ff
Selects the Fast Forward
Mode on Disc Players
and Tuning Up the AM/
FM Dial
Selects the REWind
Mode on Disc Players
and Tuning Down the
AM/FM Dial
Selects Functions for
McIntosh Home Control-
ler and as a shift key
when used with the AM
or FM push-buttons to
select utput (Spkr) 1 or
2
Press the push-button
to illuminate the keys Press to REVIEW Tuner
Station Presets and se-
lects certain functions on
McIntosh CD Players

17
How to Operate by Remote Control
The supplied remote control is capable of directly control-
ling the functions of contemporary McIntosh Source Com-
ponents connected to the MA6900. Earlier McIntosh
source components and other brand source components can
be controlled by the MA6900 with the addition of a McIn-
tosh Remote Control Translator (RCT).
Note: Your McIntosh Dealer can assist you with the
installation an operation of the Remote Control
Translator (RCT).
Mute
Press the MUTE push-button to mute audio at the Pream-
plifier OUTPUTS 1, 2 and Speaker L, R OUTPUTs. The
TAPE OUTPUTS and HEADPHONES output are not af-
fected by the MUTE function. The MUTE LED above the
push-button will flash on and off to indicate that Mute is
active. Press MUTE a second time to unmute audio.
Mono
Press the MONO push-button to combine left and right ste-
reo signals to mono at the Preamplifier OUTPUTS 1, 2 and
Speaker L, R OUTPUTs.
Trim
Press the TRIM push-button to active the Loudness Com-
pensations circuit.
Input Source Selection
Press any of the twelve input push-buttons to select a pro-
gram source. When one of the Audio/Video Inputs (SAT,
LV, TV, VCR, VCR2 and DVD) are selected by remote
control, the MA6900 will automatically switch to the
VIDEO Input. If the Front Panel VIDEO Push-button is
pressed, the source device connected to the VIDEO INPUT
Jacks will be heard. When the optional McIntosh MVS Au-
dio/Video Selector is added, multiple Audio/Video Inputs
Sources, such as LV, TV, VCR, VCR2 and DVD (V-Aux),
will become available by just pressing the desired program
source push-button on the remote control.
D/Tape Functions
Use these push-buttons to operate a CD player, CD changer
or tape recorder.
Numbered Push-buttons
Press push-buttons 0 through 9 to access tuner station pre-
sets or CD tracks/discs.
Disc and Track
Use the DISC and TRACK push-buttons when a CD player
or changer is being used.
Tuner Push-buttons
Press the AM or FM push-button to select the desired
broadcast band. Press and release the Channel Upp or
Downqpush-button to move from station to station. Press
and hold a Channel Upp or Downq push-button to move
continuously from station to station. Press REVIEW to
start the automatic brief audition of each of the presets
stored in the tuner memory. Press REVIEW a second time
to stop on a station preset and exit the Review process.
Volume
Press the Up or Down VOLUME push-button to raise or
lower the listening volume level.
Note: The TAPE OUPUTS are not affecte by volume
changes.
Amplifier Selection
Press HOME push-button followed by the SPEAKER 1 or
2 push-buttons either separately or together, to control the
rear panel OUTPUTS 1, 2 which can feed signals to a
power amplifier or other accessory component.
Acc On
Press ACC ON to turn the power ON to a McIntosh Disc
Player.
Acc Off
Press ACC OFF to turn the power OFF to a McIntosh Disc
Player.
E
Press E to perform various functions on a variety of McIn-
tosh Components. It will also pause the playing of a disc or
tape player.
Lighting
Press and release the LIGHTING push-button to momen-
tarily illuminate the upper half of the remote control push-
buttons.
Note: While the LIGHTING push-button is being epresse ,
the remote control will be unable to sen a remote
comman . When the LIGHTING push-button is release
the push-buttons will continue to stay illuminate for
approximately three secon s thus allowing you to sen
the esire comman . If any of the translucent push-
buttons are epresse , they will continue to stay
illuminate for approximately three secon s.
How to Operate by Remote Control

18
Technical 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 cre-
ated a power amplifier without compromise, using the most
advanced McIntosh circuit design concepts.
A continuous average power output rating of 200 watts
and with an output current of greater than 50 amperes per
channel, making this the most advanced Integrated Ampli-
fier McIntosh has ever manufactured. The distortion limits
for the MA6900 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 MA6900 are so low, it takes
special measuring techniques to make accurate readings.
The MA6900 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 mea-
suring were required. Extensive controlled listening tests,
the ultimate form of measuring, were made before the final
design was accepted.
Preamplifier Design Philosophy
All signal switching in the MA6900 is done by Electro-
Magnetic devices. Electro-Magnetic Switching is a proven
technology that uses the latest in materials and manufactur-
ing methods. Each switch consists of a glass tube that is
filled with an inert oxygen-
free atmosphere and sealed
with tiny leads protruding
from either end. These leads
extend into the tube and
overlap one another with a
separation of a few thou-
sandths of an inch. The leads
are made from a ferrous ma-
terial that is influenced by a
magnetic field. They are first
plated with gold as a base
material, then with rhodium
and finally ruthenium. Ru-
thenium is the best contact
material known.
The glass assembly is
then placed in the center of a
multilayer coil of copper
wire. The entire assembly is
molded together in a tough
shock absorbing material.
Bottom Inside View of the MA69
The switch and coil connectors extend from the bottom in
the form of printed circuit board terminals. When a DC
voltage is applied to the coil, current flows and creates a
Equalizer Control Adjustment Range
Hz (Hertz)
dB
(Decibel)
Figure 1

19
Technical Description
magnetic field. The force of the field causes the leads to
bend and contact one another inside the sealed glass tube.
The inert gas eliminates corrosion of the contacts and in-
sures a low resistance, distortion free switch.
All inputs, outputs, and data ports are controlled by
logic circuits in the MA6900. The logic is changed by front
panel push-buttons or by a microprocessor IR decoder.
This microprocessor IR decoder is programmed with ex-
clusive McIntosh software. It receives data from the front
panel or external sensors and provides the command sig-
nals for input switching, data switching, and volume con-
trol.
The equalizer section uses several high technology op-
erational amplifiers. The amplifier stage has been opti-
mized for the best transient performance and minimum dis-
tortion. Five other operational amplifiers are arranged in a
circuit configuration that is the equivalent of a series turned
circuit. A control potentiometer inserts this series tuned cir-
cuit into either the feedback or input section of the equal-
izer amplifier. This provides a 12dB boost or cut at the fre-
quency of the tuned circuit. Refer to figure 10. The overall
gain of the stage is 0dB when the potentiometer is at its
center detent position. In this position the tone control ele-
ments are completely removed from the signal path.
Power Amplifier Design Philosophy
The design philosophy incorporated in the MA6900 in-
volved several different techniques, all based on sound sci-
entific logic. Refer to figure 11. 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 ex-
pected from a McIntosh amplifier. The typical McIntosh
owner would never accept the approximately 100 times
higher distortion of many non-feedback designs.
All transistors are selected to have nearly constant cur-
rent gain over the entire current range they must cover.
Output transistors in particular, have matched uniform cur-
rent gain, high current-bandwidth product and large active
region safe operating area. An automatic tracking bias sys-
tem completely eliminates any trace of crossover distor-
tion. Precision metal film resistors and low dielectric ab-
sorption film capacitors are used in all critical circuit loca-
tions.
The output signal of the circuit is coupled together in
the unique McIntosh MA6900 Output Autoformer. It pro-
vides low distortion power transfer at frequencies from be-
low 20Hz to well beyond 20,000Hz with optimum imped-
Figure 11
Block Diagram of the Amplifer and Meter Circuitry

2
Input Test Signal
Figure 14
Without Power Guard
Figure 15
Top Inside View of the MA69
Figure 12
Figure 13
ance points of two ohms, four ohms and eight ohms. The
unequaled expertise of McIntosh in the design and manu-
facturing of autoformers is legendary in the high fidelity
industry.
The high efficiency circuit design of the MA6900 con-
tributes to low operating temperatures. More than 621
square inches of heat sink area keep the MA6900 operating
safely with convection cooling. No fans are needed.
Autoformers
All solid state power amplifier output circuits work best
into what is called an optimum load. This optimum load
may vary considerably from what a loudspeaker requires.
In the case of more than one loudspeaker connected in par-
allel, the load to the
power amplifier may
drop to two ohms or
even less. A power am-
plifier connected to a
load that is lower than
optimum, causes more
output current to flow,
which results in extra
heat being generated in
the power output stage.
This increase in tem-
perature will result in a
reduced life expectancy
for the amplifier.
The Autoformer creates an ideal match between the
power amplifier output stage and the loudspeaker. Refer to
figure 12. There is absolutely no performance limitation
with an Autoformer. Its frequency response exceeds that of
the output circuit itself, and extends well beyond the au-
dible range. Its distortion level is so low it is virtually im-
possible to measure. In the rare event of a power amplifier
output circuit failure, the McIntosh Autoformer provides
absolute protection from possible damage to your valuable
loudspeakers.
Protection ircuits
The MA6900 incorporates its version of the McIntosh
Sentry Monitor output transistor
protection circuit. Refer to figure
13. There is absolutely no compro-
mise in sonic performance with
this circuit, and it ensures safe op-
eration of the amplifier under even
the most extreme operating condi-
tions. The different types of pro-
tection circuits incorporated in the
MA6900 insure a long and safe operating life.
The MA6900 also includes the unique patented McIn-
tosh Power Guard circuit.
Power Guard eliminates the
possibility of ever overdriving
the amplifier into clipping. Re-
fer to figures 14, 15 and 16. An
overdriven amplifier can pro-
duce both audible and inaudible
distortion levels exceeding
40%. The audible distortion is
unpleasant to hear, but the inau-
dible ultrasonic distortion is
also undesirable, since it can
damage valuable loudspeaker
system tweeters. You will never
experience the harsh and dam-
aging distortion due to clipping.
The Power Guard circuit is a
waveform comparator, monitor-
ing both the input and output
waveforms. Under normal oper-
ating conditions, there are no
differences between the shape
of these waveforms. If an am-
plifier channel is overdriven,
there will be a difference between the two signal wave-
forms. When the difference exceeds 0.3% (equivalent to
0.3% harmonic distortion), the Power Guard activates the