Mcintosh MR 71 Owner’s Manual

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FM

STEREO

TUNER

CONTENTS

TABLE
INTRODUCTION­TECHNICAL
FRONT
BACK
INSTALLA
CONNECTIN

oPERAT|NG

ADJUSTMENTS

GUARAN

DESCRIPT]ON

PANEL

PANEL INFORMATION

Audio
Stereophonic
Monophonic

Remote Amplifie
Off-The-Air

Antenna

Stereophonic FM
Monophonic

Muting Threshol
Dial Panel
Output Adjust--

INFORMATION

Outputs

Connections-

TNSTRUCTTONS-_--=--

MR 7I

OF CONTENTS

FM

Multiplex

FM

Recording_

Multiplex_

FM

Lights-

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THANK

YOU

Judging

from
among discriminating
freshman when
to read
successful

and

partnership

equrpment.

You

have "THE BEST."

now

thousands of

you

lf

outline of

for

this manual

in ahurry,

are

what

MR 71 FM

The Mclntosh

neered,

The research staff of
has developed f ive new
ments

1.
is "clickless"
(Patent

2.
path
na
mum

3.

first
sponses.

4.

increased sensitivity which
setting

5. A new

duce noise from
carrier
tuner uses

The MR 71
lntosh PANLOC method
PANLOC

installation,

highly sensitive FM Multiplex Tuner.

for

the MR 71.

Automatic

applied

Multipath indicator to eliminate

reception by showing when

rotated

is

multipath

Double

amplifier

R.F.

New

D'Arsonval movement

adjustments.

auxiliary music

system

MR 71

stereo-mono switching that
and
for.)

to the correct

distortion.

tuned

computer

stations broadcasting

a filter.

such

also

gives you

operation, and maintenance.

is a

Mclntosh

tuner circuit

completely electronic.

position

input circuits

reduce

to

do not

designed filter

services.

uses

the exclusive Mc-

installation.

of

absolute

stereo equipment

the

music listeners.

comes

it

carefully

to stereo.

follow

these

between

hours

each control

musical enjoyment.

of

page

read

and

is 30 minutes. This

STEREO

INTRODUCTION

precision

your

spurious re-

engi-

Laboratory

improve-

multi-

anten-

mini-

for

before the

meters

need

No other

zero

to re-

sub-

The

ease

of

of

you

You are

Never-the-less

instructions

you

and

Used

properly you

first. This

3

indicator does. Reading

is time well

you

own,

your

gives you

spent.

rank high

probably

we ask

to

new

you

insure a

stereo

are in for

a brief

time

no

TUNER

PANLOC is

technique

In the PANLOC
mounted
on this shelf. Depressing
tons on the front

place

into
the

tuner depress

second

front

the

position,
the tuner from
the holding latches allows
taken

into

back

The

phonic
casts is assured
tu ner.

Once

performance
stand why Mclntosh
their reputation as "THE BEST." Your

Intosh
finest
valued

the first

to be used on stereo instruments.

first.

for normal

time. The tuner

panel,

preventing

out of the PANLOC

position

finest

possible

possible

and FM multiplex

you

have

of the MR

MR 71 tuner will

part

of

professional

system a metal

The tuner

panel

The

the

againstthe

by the Mclntosh MR 71

enjoyed the outstanding

FM

your

slides

the PANLOC

locks the tuner firmly

operation.

PANLOC

the

can

tuner

installation.

reception, and will
home

will

accidental

reception of FM mono-

stereophonic

71,

products

give you years

music

installation

into

To

buttons

now

slide

lock

release of

Depressing

the

tuner to be

shelf or to slide

mounting

you

will under-

have

system.

is

shelf

position

but-

unlock

a

from

into

this

panel.

broad-

earned

Mc-

of the

a

be

TECHNICAL

DESCRIPTION

a 6DS4

tuner

71

MR

The

the

Nuvistor

tor

form

to

of the
cascade

range
noise

A

with

reduces

value.

possible rating,
selectivity.

A
Control
As

automatically
After
gradually comes

iecond
brings
automatic
time

tion.
justable

diode
silicon
formance.

changes.

nates
temperature'compensated
tector

circuit.

narrow

tuning

muting

circuit

tion

tuning

stations

noise
muting.
be
stations.
tory

for

(triode) operates

a cascade

operating

amplifier

signals

of

ratio.

double-tuned

Nuvistor-tube

the

spurious

Sensitivity

newly

the

The

The

developed

(AFC)

circuit

tuning

station

the

interval.

tuningto

the

tuning

tuning

the

amount

The

with

circuit

AFC

place

in

diode

lt

lt has

chance

the

supplies

insures

This

band
meter

circuit.

Mclntosh

automatically

noise,

cut

set

including

in and

that

interference

and

A front

for

off

back

A

the

to

has

amplifier'

RF

first

a second

into

amplifier.

characteristics

handle

to

excellent

with

input

RF

cascade

signals
is

while

knob

cuts

is tuned

The

dial

a front

is

of

improves

unaffected

is

no

operating

detector

amplifier

developed

of

out

can't

panel
listening

correct

to

increased

still

Automatic

greatly

moved,

is

for

off

in,

operation

into

action

AFC

minimum

repeats

moved

is

action

AFC

of

panel

unique.

a conventional

the

warm-up

tube

of

signals

positive

also

and

suppresses

noises

the

a

station.

override

are

switch

to

panel adjust

muting

high-grain

Nuvis-

The

triode

Careful

a wide

circuit

extremely

an

the

to

retaining

simplifies

the

sharpest

the

automatically

distortion'

action

its

to

control'

uses

lt

overall

temperature

by

drift

filament

narrow

AFC

operates

the

ultrasonic

usually

Weak

the

suppressed

allows

weak

control

threshold

tube

design

allows

dynamic

signal-to-

combined

amplifier

highest

high

Frequency

tuning'

circuit

AFC

tuning'

circuit

AFC

over

each

new

a

fully

is

a silicon

tube'

AFC

elimi-

and

hum'

band

the

to

action'

the

ultrasonic

muting

intersta-

all

heard

distant

or

background

by

muting

and

is

the

low

a 3

This

sta-

ad'

The
per-

A

de-

AFC

The

FM

the

to

noisy

fac-

level'

mixer

The

intermediate

topped

lF transformers

The

sponse

rejection.

assures

mechanical
adequate

limiters
plete

limiters

signal-to-noise

separate

A

audio

only

frequency

wide

Both
shielded
suppression

lF

and

The

Mclntosh

this

of
adjustments

multiplex
minus

Then

main

signals

nel
separation.

A temperature
locks-in
oscillator.

noise

38KC

the

providing
ceptibility

interference

ing

highly

A
reduces
auxiliary

frequency

the

mately

27sdb

without

The

which

station
unique

output

frequency

highly

with

Construction

electrical

on

the

frequencies.

MR

circuit

right)

automatically

carrier

immunity.

50db.

per

MR

lights

circuit

selective

maximum

shock

gain

is

weakest

the

are

ratio.

wide

frequencies

resPonse'

and

RF

in excess

radiation

of

multiPlex

71

developed

is the

necessary

matrixing

stereo

signal'

then

are

highly

a

This

signal

distortion

low

spurious

to

selective
noise
music

The

octave.

affecting

has

71

when

broadcasting

using

amplified

is

stages
response

wide

have

adjacent

of the

stability

and

provided

used

band

circuits

lF

of

detector.

methods'

sidebands

combined

The

produced

stabilized

stable

method

Balanced

components

minimized

is

computer

from

services'

from

band

filter

The

normal

multiplex

a

the

a transistor

lF transformers

and

vibration'

to

signals.

for the

detector

low

for

requirements

FCC

the

of

decoder

elimination

with

left

3BKC

gives

detectors

and

signals'

stations

The

63J4KC

response

noise

program

pointer

dial

multiplex

through

flat'

with

curves'

band

channel

resistance

than

More

operate

best

distortion

are

FM

The

commonly

The

are

with

and

with

igKC

synchronous

in the

reduced

Tape

this

by

designed

broadcasting

filter

is eliminated

stereo

both

com-

Two

possible

handles

completely

oscillator

uses

advantage

critical

of

L-R
detected'

the

chan-

right

excellent

amplifier

exceptional

cancel

output,

record-

method'

reduces
approxi'
slope

material'

indicator

crosses

stereo'

operates

five

re-

to

and

for

a

used

(left

L*R

sus-

filter

is

a

A

the

2

stereo indicator lamp. The transistor

MPX

controlled
detecting bridge circuit. The circuit discrimi­nates between noise
pilot
the 19KC signal
broadcast.

The MR 71
automatic mono-stereo switching circuit.
(Pat.
out switching

The circuit switches smoothly

when the 19KC

The

ing dial is an
exclusive
signal
distortion
tion.

reception,
rotated to reduce or eliminate the

signal. The MR 71

by a noise-rejecting

and

the 19KC

signal. The

Pend.) The

multipath

Mclntosh development. Multipath

reception causes

and

knowing

By

a directional FM antenna may

indicator will light only on

present

uses a new

switching

clicks or transients.

multiplex

signal

electron

poor

the

in a multiplex stereo

Mclntosh

is electronic with-

carrier

indicator on

ray tube. This

moderate

stereo channel separa-

presence

multipath indicator

differential

multiplex

developed

and

present.

is

the tun-

to severe

multipath

of

multipath

is

silently

is

an

be

shows

if there
rapid fluctuation

With the
indicator
showing
eliminated.

Two
back

only by
other
back
feedback

nels

than sufficient output volume is available
feed

A new type of mechanical

gives
tuning action. The
directly, and in

lash
lined
duce friction and
smooth and

are multipath

of the electron

antenna

beams

that

pairs

panel.

front

the

pair

of

panel

output adjust controls.

type

provide

poweramplif

the MR

is

eliminated

pointer

remain relatively

multipath distortion

audio output

of

pa.ir

One

panel

jacks

preamplifiers

low impedance outputs.

iers as wellas

71 extremely smooth

tuning

turn

with

carriage

wear to

quiet

dial action.

signals

correctly

jacks

of

volume

is controlled

capacitor is

drives

the

this

and nylon

give

present
ray

beams.

positioned,

steady,

has been

jacks

are

on

is

controlled

control. The

only by

Two stage

on both chan-

More

preamplifiers.

tuning

design.

assembly

flywheel

driven

pointer.

an unusually

Back-

A

teflon

pulleys

by

the

the

the

to

re-

Turn antenna

Adjust to

desired

for

Tune

Power
position:

automatically from

off.

will

Use

IF YOU ARE IN A HURRY

so the

volume.

Max. reading.

stereo-auto

switch

eye is steady.

stereo to

mono.

Will light only

broadcasting M PX

for

^at

vari

for

Tune

Continuously

position

Max.

on stations

stereo.

lle

nl

te

r

black area.of

I

ablr

)lg,

ia

MP,

PX

reception.

Tuning...select

desired

ln...
noise.

weak

statio n s.

eliminates
Out...usetoreceive

station.

interstation

SPECIFICATIONS

Useable

2.5
deviation)
harmonic

IHF standards.

Audio

Within

Distortion

Less

deviation

Capture

1.5db

Muting

lF
noise

Oscillator

Less than

gible

lmage

70db

Hum

Output
Antenna

RF Amplifier

lF Stages

Limiters

Radiation

Multiplex
Multiplex

Multiplex

Multiplex

SCA Filter

Sensitivity

microvolts

for less than3/s

distortion

Frequency

lzdb

n O.5/o

tha

Ratio

at IOO%

injected

Better

Better

Approximately

300

Cascode

Five,
response.

Two.

Substantially

Better
Greater

pilot

Front

19KC

by

Peak-detecting,

50db
octave

ultrasonic

reduction

Drift

25KC

AFC

with

Rejection

than

105MC.

at

than

lnputs

balanced;

ohms

with

with

Channel

than 30db

Filter

than 48db

and

38KC

Indicator

panel

carrier-only.

Type

down

slope.

at 100%

ResPonse

from

atloo%mod

modulation.

in oPeration.

80db

70db

2.5

6DS4

200KC

below

multiplex

at 67KC

modulation

in accordance

to

20

muting:

between

AFC

with

at

below

volts;

75

Nuvistor

bandwidth,

FCC requirements.

Separation

at 1000

suppression

carrier.

stereo

self'matrixing

lo 74KC

total

20,000

u lation

at least

stations'

disabled;

90MC;

lOOTo

impedance'

low

ohms

in

cYcles.

light

(+

75KC

and

noise

with

cycles.

KC

75

t

60db

negli'

better

modulation.

unbalanced.

detector.

275db

than

first stage'

flat toP

19KC

of

activated

Per

Automatic

An exclusive
electronic
ing

Tube and

1-6DS4
I-72Af7
1-6BN4A,
1-6AU6,
1-6AU6,
1-6AU6,

1-6AU6,
1-6CS6, 5th
1-6BN8,

2-6818,

1-6U8,

i-6HU6/EM87
I-I2AU7,
1-ST2-27
1-MAi 13

2-IN542
2-1N542

4-IN542
2-LN542

2-Selenium

1-No.

Power Gonsumption

70

Dimensions

Front
high; chassis
inches
deep,
front of

172

Weight

Chassis

In shipping

Mono-Stereo

Mclntosh

automatic

(Pat.

circuit.

Semiconductor

Nuvistor,

,2nd

2nd
3rd
4th

Detector,

Left

Audio
Control.

Amplifiers.

MPX

Switch.

Lamp
Discriminator
Discriminator.

Detector.

Indicator.

MPX
Power

1850

watts,

Panel;

wide by 5

including

mounting

inches.

only, 27

Pend.).

RF

Oscillator.

lF.

1st

lF.
lF.
lF
lF 2nd

Muting

AVC ClamPer.

and Right,

Amplifier,

PX

M

Voltage

5,

(Transistor),
Diodes,
Diodes,
Diodes,

Diodes,

Rectifiers,

Supply.

Lamp, MPX

to 125

105

16

(including

carton, 37

Switch

development;

mono-stereo

Gomplement

RF.

1st

and Mixer.

and 1st

AmPlifier,

Multipath

Oscillator'

inches

inches

connectors;

pounds.

Limiter.

Limiter

Muting

1st

MPX

I ndicator.

Reference.

MPX

Band

Wide

Narrow
Balanced
Balanced

panel

Band

High

Indicator'

50 to

volts,

wide by

PANLOC

high

including

Pounds.

and 2nd

MPX

all'

switch-

and

Muting.

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ndicator

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by 13

clearance

for

cycles.

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