McIntosh MAC-1500 Owners manual

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To insure your enjoyment please read and carefully fol-
low these instructions. The time spent will make it possible

for you to enjoy thousands of hours of musical enjoyment.

If you are in a hurry read page 4 first. This gives you a

brief outline of what each control and indicator does.
Reading time for this manual is 30 minutes. This is time

well spent.

CONTENTS

GENERAL DESCRIPTION 1
SPECIFICATIONS 3
IF YOU ARE IN A HURRY 4
CABINET INSTALLATION 5
INSTALLATION-CONNECTIONS 7
COMPLETE SYSTEM HOOK-UP 9

BLOCK DIAGRAM ..... 10

FRONT PANEL INFORMA nON 12
BALANCING YOUR SYSTEM 15
ENJOYING YOUR SYSTEM 16

GUARANTEE ..... Cover

D SCRIPTION

The MAC 1500 is a stereo receiver. In one small con-
venient easy to use unit are three top notch stereo
components. A solid state preamplifier, a power ampli-

fier and an FM MPX stereo tuner are combined to give
you the best performance possible. Transistors and solid
state circuit made the MAC 1500 possible. Transistors
reduced the space necessary to combine a stereo re-

ceT~~i:,;~ith a powerful power amplifier. Solid state cir-

bunted on military specification printed circuit

s are mounted vertically. This takes less space.

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The MAC 1500 is built in three sections. Each section IS
built with maximum care and skill. Upon completion
each section is ioined with others to make a complete

unit. Each section's physical size is kept to a minimum.
The result is a compact, easy to use stereo instrument.
A stereo instrument that brings you the best in all types
of stereo listening.

The MAC 1500 is new and exciting. For the past three

years the advanced products design department
worked on this product. Every avenue and approach
was searched. New avenues were tried. New types of
circuits were tested. All approaches were evaluated.
The result is a product that comes to you with an an-

cestry founded in the most advanced technology.
A product that brings you the best of both worlds.

Where tubes give superior performance and long life
they are used. Where transistors give improved per-
formance and long life they are used. Here in one unit
you have the most advanced solid state preamplifier,
the most advanced tube and solid state multiplex cir-
cuitry, plus a conservatively rated tubed power ampli-
fier. The FM stereo tuner comes from the same engineers
who make the tuner that AUDIO magazine called

"UNEXCELLED."

The stereo solid state preamplifier in the MAC 1500
gives you full sonic control of your listening room. Bass

and treble controls have
means you can control how your speakers will sound in

±18db of boost and cut. This

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your particular room. The prime function of a preampli-
fier is to reproduce records and tapes with full accuracy

and sonic realism. Records are made with the bass cut
and the highs boosted. This allows more musical infor-
mation to be put on the record groove. Tapes are also

recorded with the bass cut and the highs boosted. For
true musical enjoyment the MAC 1500 reintroduces the
bass and the highs following accurate and definite
standards. Your records and tapes will sound alive and
thrilling when you hear them through the MAC 1500.

The solid state preamplifier uses 12 silicon planar tran-
sistors. Silicon planar transistors are used because of
their high thermal stability, low noise and superior high
frequency response. The silicon planar transistors make
the fantastic sound reproduction possible.

Despite the small space available for tuner placement
the MAC 1500 gives you a 2.5 microvolt FM stereo
tuner. This sensitive tuner brings you clear noise free

reception from distant stations. The tuner section is

superb. The reason is simple. Pride of craftsmanship.
In tuner design, one misplaced wire, one lead length
too long, one capacitor out of place, can affect the
performance of the tuner.

Each MAC 1500 must pass 171 tests before it is ready
for you. The tuner section uses six tubes and two tran-
sistors. Tubes as RF amplifiers still give maximum sensi-
tivity with greatest overload protection. It is virtually

impossible to overload the MAC 1500 with too much
signal from a nearby FM station. A transistor is used in
the oscillator because it is not susceptible to drift.

Distortion on FM is less than 0.5 %. You get all there is

to hear with this FM tuner. The MPX section of the MAC

1500 uses six transistors and two tubes. In test after test

this particular MPX section outperformed all other de-

signs. One added advantage of the predominantly

solid state design of the multiplex section is the long

life expectancy of the circuit.

POWER. This is one thing you have plenty of with the

MAC 1500. The power output section of the MAC 1500

will drive even the most inefficient speaker systems.

Here is a dual power amplifier with 30 watts continuous

power per channel with both channels operating. Dis-
tortion is less than 0.5
cycles. Now you can listen to music with the knowledge
your power amplifier delivers all the power your
speakers need. Good full rich music is yours with the

MAC 1500.

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FM TUNER SECTION:

USABLE SENSITIVITY (at 100 % modulation): 2.5uV

(I.H.F. Standards)

SIGNAL TO NOISE AND HUM RATIO: 65db.

HARMONIC DISTORTION: Mono, less than .5

Stereo, less than .8 %

DRIFT: Less than 25KC

FREQUENCY RESPONSE: Flat from 20 cps to 20KC

with standard 75 fL second deemphasis and 19KC
pilot frequency filter.

CAPTURE RATIO: Better than 2.0db.

IMAGE REJECTION: Better than 60db.

STEREO MULTIPLEX SEPARATION: Better than 30db

at 1KC.

SPECIAL FEATURES:

a) Automatic stereo switching.
b) Muting: IF Injected circuit with at least 50db

quieting between stations.

cl Antenna inputs for 300 ohm balanced (for twin

lead) and 75 ohm unbalanced (for coaxial cable).
d) Nuvistor RF amplifier, Nuvistor mixer.
e) Four stages of IF amplification, with AGC used to

insure that limiting occurs only in the limiter stages.

f) Two limiter stages used for exceptional capture

ratio and smooth muting operation.

g) Multiplex filter and SCA filter, to suppress 19KC

and 38KC signal components at least 40db below

program and to suppress 67KC SCA by 60db.

h) Noise immune logic circuit used to activate MPX

stereo light and automatic stereo switching on

19KC stereo pilot only.

i) D'Arsonval tuning meter for accurate center of

channel tuning.

j) Flywheel tuning for ease of operation and precise

tuning.

%

RES AND SPECIFICATIONS FOR MAC 1500

AMPLIFIER SECTION:

POWER OUTPUT: 60 watts continuous, 30 watts per

channel, 85 watts total music power (I.H.F. Stand-
ards).

HARMONIC DISTORTION: Less than 0.5

20KC, both channels operating at rated output at

the same time.

INTERMODULATION DISTORTION: Less than 0.5

for any combination of frequencies from 30 cps to

20KC at rated output (equivalent RMS watts). I.M.
decreases as output power is reduced.

FREQUENCY RESPONSE:

(Power amplifier response is 2 cps to 150KC at

- 3db; power bandwidth is 19 cps to 30KC.)

OUTPUT IMPEDANCE: 4, 8, and 16 ohms. Rated out-

put is delivered by any of these impedances.

DAMPING FACTOR: Greater than 10.

INPUT SENSITIVITY AND IMPEDANCE:

Tape Head-2.8MV, 1 megohm

Phono 1-5.6MV, 47K ohms

Phono 2-2.8MV, 47K ohms
Aux-400MV, 500K ohms
Tape Monitor-400MV, 500K ohms

TAPE OUTPUT LEVEL: Tuner-1 .2 volts, for other inputs

400MV at rated sensitivity.

HUM AND NOISE:

Power Amplifier, - 90db
High Level Inputs, - 75db

Low Level Inputs, - 60db

TONE CONTROL RANGE:

Bass control

Treble control +15db to - 15 db at 10KC.

L.F. and H.F. FILTER:

L.F. filter, cutoff frequency
attenuation rate

+15db to - 18db at 50 cps.

= 12db per octave

±0.5db 20 cps to 20KC.

= 50 cps,

% 30 cps to

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H.F. filter, cutoff frequency
attenuation rate

SPECIAL FEATURES:

a) Loudness control for full fidelity listening at low

levels.

b) Tape monitor switch for listening to recorded tape

program while recording.

c) Tone controls are "clutched" for tracking opera-

tion of left and right channels or independent
operation.

d) Headphone output fed from special tap on output

transformer for maximum signal to noise ratio.
Speakers may be automatically muted when head-
phone plug is inserted, by use of rear mounted

switch.

e) Silicon transistors used in all preamplifier stages

for low noise and hum free operation.

f) High quality epoxy circuit boards for reliable long

life performance.

g) High quality conservatively operated components

are used throughout for long life.

h) Zener regulated power supply is used for critical

circuits.

i) Equalization and tone control circuits are feed-

back type for lowest distortion and greatest accu-
racy.

MISCELLANEOUS

FINISH: Gold anodized panel and knobs, black finished

chassis.

DIMENSIONS: 16" wide, 5%" high, 16" deep.
WEIGHT: 40 lbs., shipping weight 54 lbs.
POWER CONSUMPTION: 180 watts, 120 volts, 60 cps.

TRANSISTOR AND TUBE COMPLEMENT:

19 silicon transistors

1 germanium transistor

15 tubes
16 diodes, rectifier, and zener diode

= 12db per octave

= 5KC

3

IF YOU'RE IN A

1 Input Selector ... Aux ... for any device con-

nected to the AUX inputs on back. FM MONO
listen to FM mono broadcasts. FM AUTO ...

listen to FM stereo broadcasts. Phono
phonograph records. Phono 2 for phonograph

records. Tape hd. for a tape playback unit
without preamplifier.

1 for

2 Tune for center of black area.

3 Adjust to desired volume. Power off. Turns the

system on/off.

4 Tuning ... select desired station.

5 Treble ... modifies high frequency sounds. Set

to your taste.

6 Bass ... modifies low frequency sounds. Set to

your taste.

7 Headphone ... to connect a set of low imped-

ance stereo headphones.

8 Loud ... use this switch to compensate for low

volume listening and still hear full frequency
range.

9 HF Filter In ... reduces high frequency noise

such as record surface noise.

8AlANCE

10 LF Filter In ... reduces low frequency noise

such as turntable rumble.

11 Muting In eliminates interstation noise.

Muting Out use to receive weak stations.

12 Tape Mon monitor position used to monitor

a recording when used with a tape recorder
with separate playback and record heads.

MUST BE IN OUT POSITION FOR NORMAL
LISTENING.

13 Stereo ... Mono ... Set to stereo for all stereo

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program material. Mono position for all mono
material.

14 Balance ... to make one speaker louder than

the other. Permits you to adjust for unequal
sound caused by room acoustics or program

material.

15 Will light only on stations broadcasting MPX

stereo.