FUSE
The MC240 uses a 3.2 ampere slo-blo
type fuse. The auxiliary AC socket is not
fused.
AC OUTLET
The auxiliary AC outlet can be used to
supply power to other equipment in the
system. The outlet will provide a maximum of
300 watts of power. The AC outlet is not fused.
LINE VOLTAGE
The MC240 operates on any line voltages
between 105 volts and 130 volts, 50 cycles to
60 cycles. The switch marked LINE VOLTAGE
changes the tap on the primary of the power
transformer. The switch can be adjusted at
any time.
INSTALLATION
Adequate ventilation extends the trouble-
free life of electronic instruments. It is
generally found that each 10° centigrade
(18° F) rise in temperature reduces the life of
electrical insulation by one half. Adequate
ventilation is an inexpensive and effective
means of preventing insulation breakdown
that results from unnecessarily high operat-
ing temperatures. The direct benefit of ade-
quate ventilation is longer, trouble-free life.
The suggested minimum space for mount-
ing the MC240 is 20" long x 14" wide x 10"
high. Always allow for air flow either by
ventilation holes or space next to the bottom
of the amplifier and a means for the warm
air to escape at the top,
The MC240 can be mounted in any posi-
tion except upside down. If the amplifier is to
be installed on a vertical surface it is recom-
mended that the transformers be on the
down side. The advantage of this position is
that the flow of heat from the tubes rises
vertically and does not tend to heat the
transformers.
If the MC240 is to be permanently mounted
use the two mounting flanges supplied with
the amplifier. The flanges are shipped sepa-
rately and 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 with 4 plastic feet on the bot-
tom cover. Remove the 4 plastic feet. Re-
move the three self tapping screws at one
end of the amplifier that hold the bottom
cover to the chromium chassis. Place the
square edge of the mounting flange with the
three round holes positioned over the three
holes in the bottom cover. The three holes in
the mounting flange will line up over the
three holes in the chassis. Replace the three
self tapping screws through the mounting
flange and bottom cover. The mounting
flange is now firmly attached to the ampli-
fier. The mounting flange on the other end of
the amplifier is installed in the same way.
Fig. 4—Bottom of MC240 with mounting flanges attached.
Place the MC240 mounting template on
the area where the amplifier is to be mounted.
Center punch the mounting shelf through
the 4 slotted holes in the mounting flanges
shown on the template. Remove the template
and install four #10 round head screws in
the center punch marks. Do not tighten these
screws. Place the amplifier over the screw
heads and slide the amplifier to either side
in the slotted holes of the mounting flanges.
The # 10 wood screws can then be tightened
securely.
INPUT-STEREO
The shielded cable from the left output of
the Mclntosh preamplifier is plugged into
the jack marked STEREO INPUT-L. The
shielded cable from the right output of the
Mclntosh preamplifier is plugged into the
jack marked STEREO INPUT-R.
CONNECTING THE MC240
INPUT-TWIN AMP
The shielded cable from the left program
source is plugged into the jack marked
TWIN INPUT-L. The shielded cable from the
right program source is plugged into the
jack marked TWIN INPUT-R.
5
