background image

MC240 STEREO POWER AMPLIFIER

GENERAL DESCRIPTION

Over one million watts of amplifier output

power capacity have been manufactured by

Mclntosh since 1947. In this 1,000,000watts

of audio power there are less than 10 watts of
distortion capacity and less than 1/100 watt
of noise capacity!

The dramatic difference in the quality of

music reproduction when you listen through

Mclntosh instruments is directly due to low

distortion performance. Careful, devoted

research is a way of life at Mclntosh. The

world's finest amplifier is the creation of per-

severing, resourceful Mclntosh engineers.
Mclntosh Laboratory is the only manufac-

turer in the entire industry to guarantee the

lowest distortion at all audio frequencies, at

full power. The U.S. Patent Office has rec-

ognized the advanced technology of the

Mclntosh circuit by granting 6 patents.

1

Long life, flexibility, highest quality con-

struction are characteristic designs in every
Mclntosh instrument. Wide electrical and

thermal margins of safety for all components
and tubes, advanced engineering, and cool
operating design add to the long life built

into every Mclntosh product. Reliability pro-

longs your investment without expensive
maintenance costs.

The MC240 has on one chassis two 40

watt power amplifiers. In addition to use as a

stereo amplifier, the flexibility of the MC240

permits it to be used as a monophonic

amplifier that delivers 80 watts, or as two

separate 40 watt amplifiers with each chan-

nel amplifying completely separate pro-

grams, or as two amplifiers for use with an

electronic crossover network. Such flexi-

bility permits maximum use for greatest
return from your investment.

TECHNICAL DESCRIPTION

The patented Mclntosh Unity Coupled

circuit and output transformer have estab-

lished Mclntosh amplifiers as the unchal-
lenged leaders in the audio field.

Before 1947, low distortion at high power

and high efficiency was impossible. A com-

pletely new engineering approach resulted in
an amplifier that for the first time permitted

high power with distortion below 1%. That
new engineering produced the Mclntosh
Unity coupled circuit and the Mclntosh bifilar

wound output transformer. With the intro-
duction of the Mclntosh amplifier new stand-
ards for distortion-free performance were

established.

turn of primary number one is next to the

same turn of primary number two. There is

almost complete magnetic coupling between
the two wires. The magnetic coupling is rein-
forced by the capacitance between the
two wires.

INPUT

OUTPUT

Fig. 1 —Representation of bifilar winding.

The Mclntosh output transformer is

unique. It has two primary windings which are

wound bifilarly. In the bifilar technique both

primary wires are wound side by side. Each

Fig. 2 —Representation of Mclntosh output circuit.

1

1

U.S. Patent No's: 2,477,074; 2,545,788; 2,646,467; 2,654,058; 2,860,192; 2,929,028.

Summary of Contents for MC 240

Page 1: ...DESCRIPTION 1 PANEL FACILITIES 4 INSTALLATION 5 CONNECTIONS 5 Input Stereo 5 Input Twin Amp 5 Input Mono 6 Output Stereo or Twin Amp 6 Output Mono 6 Line Output Stereo or Twin Amp 6 Line Output Mono 7...

Page 2: ......

Page 3: ...ty of the MC240 permits it to be used as a monophonic amplifier that delivers 80 watts or as two separate 40 watt amplifiers with each chan nel amplifying completely separate pro grams or as two ampli...

Page 4: ...ack loop which reduces their distortion reduces their internal generator resistance and reduces their balance requirements The Mclntosh circuit in reality perfects push pull high efficiency output cir...

Page 5: ...0 7 volts Mono Isolated from ground 25 volts Center tap internally grounded 140 volts One side internally grounded 70 7 volts Internal Impedance Less than 10 of rated load impedance Input Input impeda...

Page 6: ...t has a GAIN control that permits connecting signal sources up to 30 volts without overloading the amplifier s input The input impedance is 250 000 ohms OUTPUT The two barrier terminal strips marked O...

Page 7: ...nd must be attached to the amplifier bottom at each end Turn the MC240 over with the transform ers down and place it on a piece of cloth or cardboard to prevent scratches The ampli fier is shipped wit...

Page 8: ...the output volt ages are not the same phase and amplitude If the speaker impedance is 2 ohms 4 ohms 8 ohms 16 ohms 32 ohms Connect one speaker lead to the screw marked LEFT COM and the other to LEFT 4...

Page 9: ...the following adjustments have been completed the MC 240will operatewithoutanyfurtherattention ADJUSTMENTS LINE VOLTAGE The LINE VOLTAGE switch should be set to the position that more closely matches...

Page 10: ...oes not depend on the critical adjustment of bias or balance controls in the output circuit The patented Mclntosh circuit delivers its adver tised specifications without any need for these controls an...

Page 11: ......

Page 12: ...2 CHAMBERS STREET BINGHAMTON N Y Phone Area Code 607 723 5491 LABORATORY INC Made in U S A PRINTED IN U S A 1M 038 002...

Reviews: