McIntosh MC 7300 User manual

IMPORTANT
SAFETY
INSTRUCTIONS
THESE
INSTRUCTIONS
ARE
TO
PROTECT
YOU
AND
THE
McINTOSH
INSTRUMENT.
BE
SURE
TO
FAMILIARIZE
YOURSELF
WITH
THEM.
1. Read all instructions - Read the safety and
operating instructions before operating the
instrument.
Retain
Instructions
-
Retain
the
safety
and
operating instructions for future reference.
Heed
warnings
-
Adhere
to
warnings
and
operating instructions.
4.
Follow
Instructions
-
Follow
all
operating
and
use
instructions.
WARNING: TO REDUCE RISK OF FIRE OR
ELECTRICAL SHOCK, DO NOT EXPOSE THIS
INSTRUMENT
TO
RAIN
OR
MOISTURE.
Power Sources - Connect the power supply only to
the type described in the operating instructions or
as
marked
on
the
unit.
Power-Cord
Protection
-
Route
power-supply
cords
so that they are not likely to be walked on or
pinched by items placed upon or against them,
paying particular attention to cords at plugs,
convenience
receptacles,
and
the
point
where
they
exit from the instrument.
Ventilation - Locate the instrument for proper
ventilation.
For
example,
the
instrument
should
not be placed on a bed, sofa, rug, or similar
surface
that
may
block
ventilation
openings;
or,
placed
in
a
built-in
installation,
such
as
a
bookcase
or cabinet, that may impede the flow of air
through the ventilation openings.
Heat - Locate the instrument away from heat
sources
such
as
radiators,
heat
registers,
stoves,
or
other
appliance
(including
amplifiers)
that
produce
heat.
Wall or Cabinet Mounting - Mount the instrument
in
a
wall
or
cabinet
only
as
described
in
the
owners manual.
10.
Water
and
Moisture
-
Do
not
use
the
instrument
near
water
-
for
example,
near
a
bathtub,
washbowl,
kitchen
sink, laundry
tub, in a wet
basement,
or
near
a
swimming
pool,
etc.
11.
Cleaning
-
Clean
the
instrument
by
dusting
with
a
dry cloth.
Clean
the panel
with a cloth moistened
with
a
window
cleaner.
12.
Object
and
Liquid
Entry
-
Do
not
permit
objects
to
fall
and
liquids
to
spill
into
the
instrument
through
enclosure
openings.
~
9
S
е
м
e
so
13.
Nonuse
Periods
-
Unplug
the
power
cord
from
the
AC
power
outlet
when
left
unused
for
a
long
period
of
time.
14.
Damage
Requiring
Service
-
Service
must
be
«
performed
by
qualified
service
personnel
when:
A.
The
power
supply
cord
or
the
plug
has
been
damaged;
or
4
B.
Objects
have
fallen,
or
liquid
has
been
spilled
into
the
instrument;
or
C.
The
instrument
has
been
exposed
to
rain;
or
D.
The
instrument
does
not
appear
to
operate
nor-
mally
or
exhibits
a
marked
change
in
performance;
or
E.
The
instrument
has
been
dropped,
or
the
enclosure
damaged.
15.
Servicing
-
Do
not
attempt
to
service
beyond
that
described
in
the
operating
instructions.
АП
other
service
should
be
referred
to
qualified
service
personnel.
16.
Grounding
or
Polarization
-
Do
not
defeat
the
bs
inherent
design
features
of
the
polarized
plug.
Non-polarized
line
cord
adaptors
will
defeat
the
safety
provided
by
the
polarized
AC
plug.
17.
CAUTION:
TO
PREVENT
ELECTICAL
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
PREVENIR
LES
CHOCS
ELECTRIQUES
PAS
UTILISER
CETTE
FICHE
POLARISEE
AVEC
UN
PROLONGATEUR,
UNE
PRISE
DE
COURANT
OU
UNE
AUTRE
SORTIE
DE
COURANT,
SAUF
SI
LES
LAMES
PEUVENT
ETRE
5
INSEREES
А
FOND
SANS
EN
LAISSER
AUCUNE
PAR-
TIE
A DECOUVERT.

A
й
ў
The
lightning
flash
with
arrowhead,
within
ап
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.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION:
TO
PREVENT
THE
RISK
OF
ELECTRIC
SHOCK,
DO
NOT
REMOVE
COVER
(OR
BACK).
NO
USER-SERVICABLE
PARTS
INSIDE.
REFER
SERVICING
“ТО
QUALIFIED
PERSONNEL.
A
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.
\
E go
?
The
serial
number,
purchase
date,
and
McIntosh
Laboratory
Service
Contract
number
are
important
to
you
for
possible
insurance
claim
or
future
service.
Record
this
information
here.
Вела
та
Serial Number
p
ys
Purchase Date
(ана
Service Contract Number
Upon
application,
McIntosh
Laboratory
provides
a
Service
Contract
to
the
original
purchaser.
Your
McIntosh
Authorized
Service
Agency
can
expedite
repairs
when
you
provide
the
Service
Contract
with
the
instrument
for
repair.
Copyright
1991
©
by
McIntosh
Laboratory
Inc.

Contents
INTRODUCTION 3
INSTALLATION 4, 5
HOW ТО CONNECT INPUTS 6
CONNECTING DIAGRAMS 7,8
HOW TO CONNECT
OUTPUTS 9, 10
FRONT PANEL CONTROLS 11
REAR PANEL 12
PERFORMANCE LIMITS 13
PERFORMANCE
CHARTS
14
TECHNICAL DESCRIPTION 15, 16
BLOCK DIAGRAM 17
Take
Advantage
of
3
Years
of
Contract
Service.
.
.
Fill in the Application
NOW.
Your MC 7300 Power Amplifier will give you many
years of satisfactory performance. If you have any
questions, please contact,
CUSTOMER
SERVICE
-
McIntosh
Laboratory
Inc.
2 Chambers Street
Binghamton, New York 13903-2699
Phone: [phone]
McINTOSH THREE YEAR SERVICE CONTRACT— — — — — — )
An application for A THREE YEAR SERVICE CONTRACT is included with this manual.
The terms of the contract are:
1. If the instrument covered by this contract becomes
defective, McIntosh will provide all parts, materials,
and labor needed to return the measured perform-
ance of the instrument to the original performance
limits free of any charge. The service contract does
not cover any shipping costs to and from the
authorized service agency or the factory.
2.
Any
McIntosh
authorized
service
agency
will
repair
all McIntosh instruments at normal service rates.
To receive the free service under the terms of the
service contract, the service contract certificate
must accompany the instrument when taken to the
service agency.
3. Always have service done by a McIntosh
authorized service agency. If the instrument is
modified or damaged as a result of unauthorized
repair the service contract will be cancelled.
Damage by improper use or mishandling is not
covered by the service contract.
4. The service contract is issued to you as the
original purchaser. To protect you from
misrepresentation this contract cannot be
transferred to a second owner.
5. Units in operation outside the United States and
Canada are not covered by the McIntosh Factory
Service Contract, irrespective of the place of .
purchase. Nor are units acquired outside the USA -
and Canada, the purchasers of which should
consult with their dealer to ascertain what, if any, ,
service contract or warranty may be available i
locally.

де
| ~The electrical and mechanical design of the
MC 7300 power amplifier is the result of the many
years of engineering and manufacturing experience
of the design staff at McIntosh. This "Know How”,
along with the meticulous attention to design and
production details, makes the MC 7300 one of the
finest amplifiers ever produced by McIntosh
Laboratory.
The use of 10 complimentary connected output
transistors per channel, allows not only full power
output
into
normal
loads,
but
extra
high
current
out-
-put to drive uneven speaker loads. Some speaker
designs
have
impedance
characteristics
that
may
dip
to
as
low
as
1
or
2
ohms
at
certain
frequencies.
It
is
‘possible for the MC 7300 to deliver as much as 85
amperes peak current into these lower impedance
loads.
The MC 7300 will supply this extra current output
with complete reliability due to the use of McIntosh
Sentry Monitor protection circuits. Some power
amplifier
manufacturers
have
claimed
that
their
pro-
ducts do not use protection circuits since they com-
promise performance. The real genius of McIntosh
engineering design has recognized these potential
problems and completely eliminated them. Properly
designed
protection
circuits
assure
you
an
amplifier
. hat will operate under all types of user conditions
with maximum reliability and freedom from possible
speaker or amplifier damage. The benefits of these
designs mean you own an amplifier that will con-
tinue to operate safely for many years.
The MC 7300 output is so distortion free, it is dif-
ficult
to
measure
with
conventional
instruments.
The
performance limit is 0.005% maximum distortion, yet
it is typical for an amplifier to measure less than
0.00296 at mid frequencies.
The power output watt meters on the MC 7300 are
peak responding, and indicate the TRUE power out-
put of the amplifier. The MC 7300 meter circuits are
constantly measuring both voltage and current
delivered into the speaker loads. A speaker may have
a different load impedance at different frequencies,
resulting in a change of output current. The MC 7300
meters properly react to this condition and indicate
Real Output power.
Other desirable features are included such as high
current gold plated output terminals that will accept
cable
up
to
0.204
inches
in
diameter.
Balanced
input
connectors
are
also
provided
in
addition
to
the
nor-
mal RCA inputs.
As in all Mcintosh power amplifiers, the famous
patented McIntosh POWER GUARD circuit is includ-
ed. You never have to be concerned with amplifier
overdrive
when
playing
wide
dynamic
range
program
sources such as compact discs.
Refer to the technical description for a full account
of all the outstanding circuit and performance
features of this superb power amplifier.
INTRODUCTION
3

LOCATION
The MC 7300 may be installed in a McIntosh
cabinet or custom installed in furniture of your
choice. Always provide adequate ventilation. The
trouble-free
life
of
an
electronic
instrument
is
greatly
extended by providing sufficient ventilation. This
prevents the build-up of high internal temperatures
that cause deterioration of circuit components. Allow
enough clearance so cool air can enter at the bottom
of the cabinet and be vented from the top. Allow at
least
1
1/2
inches
(3.8
cm)
above
the
amplifier
so
the
airflow is not obstructed.
The recommended minimum space for installation
is
17
inches
(43.2
cm)
wide,
16
inches
(40.7
cm)
deep,
(including connectors), and 8 inches (20.3 cm) high.
Allow 1 inch (2.54 cm) in front of panel for knob
clearance.
CUSTOM INSTALLATION
The PANLOC system of installing equipment
conveniently and securely is a product of McIntosh
research. The PANLOC buttons on the front panel
will lock the unit firmly in place when turned ap-
proximately
one-quarter
turn
clockwise.
A
one-
quarter counterclockwise turn of the PANLOC but-
tons unlocks the chassis from its mounting.
To install the instrument in a McIntosh cabinet,
follow the instructions that are enlcosed with the
cabinet. For any other type of installation follow
these instructions:
1. Unpack from Carton
Open
the
carton
and
remove
the
PANLOC
brackets,
hardware
package,
and
mounting
template.
Remove
-
the
instrument
from
its
plastic
bag
and
place
it
up-
side
down
on
the
shipping
pallet.
Unscrew
the
four
plastic
feet from the bottom
of the chassis.
2. Mark the Cabinet Panel
Tape the mounting template in position on the
cabinet panel where the instrument is to be install-
ed. The broken lines that represent the outline of
the
rectangular
cutout
also
represent
the
outside
dimensions
of
the
chassis.
Make
sure
these
lines
clear
shelves,
partitions,
or
any
equipment.
With
the
template
in
place,
first
mark
the
six
A
and
B
holes
and
the
four
small
holes
that
locate
the
corners
of
the
cutout.
Then,
join
the
four
corner
markings
with
pencil lines, using the edge of the template as a
straightedge.
3. Drill Holes
Use
a
drill
with
a
3/16
inch
(5
mm)
bit
held
perpen-
dicular
to
the
panel
and
drill
the
six
A
and
B
holes.
Then,
using
a
drill
bit
slightly
larger
than
the
tip
of
your saw blade,
drill one hole at each of two
diagonally
opposite
corners.
The
holes
should
barely
touch
the
inside
edge
of
the
penciled
outline.
Before
taking
the
next
step,
make
sure
that
the
six
A
and
B
.
holes have been drilled.
ud
ПЫ
ў
Кара

4. Saw the Panel Cutout
First
make
the
two
long
cuts
and
then
the
two
short
cuts.
After
the
rectangular
opening
has
been
cut
out,
use
a
file
to
square
the
corners
and
smooth
any
irregularities
in
the
cut
edges.
5.
Install
the
Mounting
Strips
In
the
hardware
package
are
two
mounting
strips,
and
two
4-40
x
1-1/4"
(31.8
mm)
black
screws
that
have
a
flat
head.
Use
these
screws,
one
on
each
end,
to
fasten
the
mounting
strips.
They
are
attached
..
through
the
center
hole,
marked
В
on
the
template.
Make
sure
the
screw
heads
are
drawn
flush
or
slight-
ly
into
the
wood
before
attaching
the
PANLOC
. brackets.
6.
Attach
the
PANLOC
Brackets
Using
two
6-32
x
1-1/4"
(31.8
mm)
screws
in
the
A
holes
on
each
side,
attach
the
PANLOC
brackets
to
the
cabinet
panel;
the
short
flange
is
mounted
against
the
front
(face)
of
the
cabinet
panel.
The
screws
pass
through
the
PANLOC
bracket
flange,
the
cabinet
panel,
and
then
through
the
mounting
strips
previously
mounted.
7. install the Instrument
Guide
the
AC
power
cord
through
the
panel
opening
to
the
back
of
the
cabinet;
then,
slide
the
instrument
into
the
opening
carefully
so
that
the
rails
on
the
bottom
of
each
side
of
the
chassis
engage
the
tracks
on
the
mounting
brackets.
Continue
to
slide
the
in-
strument
into
the
cabinet
until
the
front
panel
is
flush
with
the
cabinet
panel.
Turn
the
PANLOC
but-
tons
at
the
lower
left
and
right
corners
of
the
instru-
ment
panel
clockwise
to
lock
the
unit
firmly
in
the
cabinet.
Turn
the
PANLOC
buttons
counterclockwise
to
unlock
the
instrument.
It
can
then
slide
outward
to
permit
the
removal
of
the
instrument
from
the
cabinet.
INSTALLATION
5

CONNECTING
CABLES
Use
shielded
cables
to
connect
the
signal
from
the
preamplifier
or
other
signal
source
to
the
power
amplifier.
To
minimize
the
possibility
of
hum,
the
cables
should
be
located
away
from
speaker
connect-
ing
cables
and
AC
power
cords.
Use
good
quality
cables.
Your
dealer
can
advise
you
on
the
type
and
lengths
of
cables
that
will
best
suit
your
installation.
STEREO
OPERATION
(UNBALANCED
INPUTS)
Use
shielded
single
conductor
cable
with
RCA
type
plugs.
Connect
the
cable
from
the
left
channel
out-
put
of
a
preamplifier
to
the
LEFT
UNBALANCED
IN-
PUT
on
the
power
amplifier.
Connect
the
right
chan-
nel
output
to
the
RIGHT/MONO
UNBALANCED
INPUT.
Set
the
MODE
switch
to
STEREO.
STEREO
OPERATION
(BALANCED
INPUT)
Modern
technology
has
made
it
possible
to
build
preamplifiers
and
power
amplifiers
with
the
high
signal
to
noise
ratio
necessary
to
reproduce
the
sound
quality
present
on
compact
discs
or
any
other
wide
dynamic
range
signal
source.
It
is
possible
for
conventional
interconnecting
cables
to
pick
up
electrical
interference
from
other
equipment,
AC
cables
or
electrical
appliances.
Using
the
balanced
inputs
provides
an
additional
40dB
more
protection
against
such
noise
pickup.
Use
2
conductor
shielded
cables
with
XLR
type
connectors
to
connect
between
the
preamplifier
and
the
power
amplifier.
The
maximum
effect
of
balanc-
ed
cables
is
realized
when
both
the
preamplifier
and
power
amplifier
have
similar
XLR
balanced
connectors.
Connect
the
left
balanced
output
cable
from
a
preamplifier
to
the
LEFT
BALANCED
INPUT
on
the
power
amplifier.
Connect
the
right
output
to
the
RIGHT
BALANCED
INPUT.
Pin
configuration
for
the
XLR
INPUT
connectors
on
the
MC
7300.
PIN 1: Shield or ground.
PIN 2: + output.
PIN 3: - output.
In
stereo
installations
where
the
amplifier
and
preamplifier
are
close
to
each
other
and
require
in-
terconnecting
cables
of
six
feet
or
less,
using
quality
unbalanced
connecting
cables
is
usually
perfectly
satisfactory.
If
the
units
are
farther
apart
and
require
longer
interconnecting
cables,
using
balanced
cables:
-
will
give
extra
protection
from
noise
or
interference.
MONOPHONIC
BRIDGE
OR
PARALLEL
A
rear
panel
MODE
switch
allows
the
amplifier
to
be
used
in
normal
STEREO,
MONO
(BRIDGE)
or
MONO
(PARALLEL).
When
switched
to
either
MONO
(BRIDGE),
or MONO
(PARALLEL)
operation,
the
RIGHT
BALANCED
and
UNBALANCED
inputs
are
the
only
ones
used
for
the
mono
input
signal.
The
LEFT
inputs
are
automatically
disconnected.
Connect
the
appropriate
cable
from
a
preamplifier
or
other
mono
source
to
the
appropriate
RIGHT
UNBALANCED
or
BALANCED
amplifier
input.
6
HOW
TO
CONNECT
INPUTS

14
2.5
SENSITIVITY
момо
ш!
SWITCH
AT
2.5V
PLACE
MODE
SWITCH
MONO
IN STEREO кай UN | | PARALLEL
^
STEREO
CONNECTIONS
INPUT
SENSITIVITY
PLACE
INPUT
McINTOSH PREAMPLIFIER
@ DIGITAL DYNAMIC STEREO POWER AMPLIFIER
" EIN USA,
ө Cr cr
|
|
|
|
|
Шпіае!т
мстзоо
|
Е
|
|
|
|
3
oa
000000 gy
LEFT OUTPUT RIGHT OUTPUT
с
12
u
з
в?
п
яв
етае...
ят
КУ
LEFT
8
OHM
8
OHM
SPEAKER
SPEAKER
E
MONO
BRIDGE
CONNECTIONS
INPUT
SENSITIVITY
PLACE
INPUT
NON
14
2.5
SENSITIVITY
BRID
SWITCH
AT
2.5V
PLACE
MODE
SWITCH
2:
ira
m
IN
MONO
(BRIDGE)
я
ГШ
|
PARALLEL
|
|
|
Пе
|
McINTOSH
PREAMPLIFIER
[o]
DIGITAL,
DYNAMIC
STEREO
POWER
AMPLIFIER
|
ex
I.
ecce
|
сте
cr
=
е
===>
e
900000
=,
LEFT OUTPUT RIGHT OUTPUT
о
ц
2
ас
а м
яв
aa
фа
8 OHM
SPEAKER
CONNECTING
DIAGRAMS
7

MONO
PARALLEL
CONNECTION
MONO
BRIDGE
MONO
INPUT
SENSITIVITY
1.4 2.5
PLACE MODE SWTICH
IN MONO (PARALLEL)
А
Ше
об!
мс7300
о
DIGITAL
ER
AMPLIFIER
STEREO]
E
INPUT
SENSITIVITY
р
E
~)
INPUTS
terr пачтмоно
LEFT
OUTPUT
RIGHT
OUTPUT
EE
e]
P
[ЕЈ [ЕЈ
=
R2 Ra вв
L— Unmacanceo —
[77 пмацеве —
m S
4 OHM
SPEAKER
PLACE INPUT
SENSITIVITY
SWITCH AT 2.5V
8 CONNECTING DIAGRAM
NA