Page 2
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
1U.S. Patent No's: 2,477,074; 2,545,788; 2,646,467; 2,654,058; 2,860,192; 2,929,028.
