General
installation
The MPI 4 is a laboratory-grade instrument. It provides
the facility to continuously monitor the quality of the per-
formance of a stereo system. The MPI 4 can sample and dis-
play signals from the tuner, preamplifier and power ampli-
fier without reconnecting cables. Signals are displayes on an
oscilloscope screen calibrated with scales for tuning,
measuring and testing.
As a tuning aid, the instrument is a guide to exact FM
station selection and precise tuning. The screen displays
FM signal strength, modulation percentage and mulitpath
interference. Audio signals may be viewed for stereo bal-
ance, strength, phase and channel separation. Output power
of the power amplifier can be seen at any instant during
program performance, or stored to develop a trend over
several minutes.
With the addition of test records, the MPI 4 can show
compliance and trackability of a phono pickup, frequency
response of the preamplifier and power amplifier, audio
distortion and stereo speaker balance.
In one of its operational modes, the MPI 4 becomes a
"dual trace" oscilloscope. When operated in the dual trace
mode the left and right stereo channels appear simul-
taneously and separately on the screen for direct compari-
son. The instrument also has "triggered sweep." It permits
the viewer to choose a single tone and lock it on the screen
for careful inspection.
In a search for convenient equipment-mounting tech-
nique, Mclntosh developed the PANLOC system. Pressing
the two PANLOC buttons on the front panel of the MPI 4
releases the unit to slide in or out of its mounting. This
allows easy access to cable connections at the rear. It
brings top panel controls into view for easy adjustments,
adjustments.
Ventilation extends the trouble-free life of an instru-
ment by preventing excessive internal temperature and
insulation breakdown. To accomplish this, allow cool air
to enter at the bottom of the instrument and warm air to
escape at the top. The MPI 4 Maximum Performance In-
dicator may be mounted in any position. It requires a
mounting space 15 inches deep (38.1 cm), 17½ inches
wide (44.45 cm), and 6 inches high (15.24 cm).
To mount in the Mclntosh cabinet follow the instruc-
tions enclosed with the cabinet. For any other installation,
remove the instrument, PANLOC brackets, parts bag and
mounting template from the carton. Remove the MPI 4
from the plastic bag and place it upside down on the
shipping pallet. Then remove the four plastic feet fastened
to the bottom of the chassis.
1. POSITION TEMPLATE AND MARK
Position the plastic mounting template over the area of
the cabinet panel where the MPI 4 is to be installed.
Be sure that the edges of the equipment marked on the
template clears any shelves, partitions or existing
equipment located behind the panel. With the template
in place mark the six "A" and "B" holes and four smalt
holes locating the corners of the cutout. Next, join the
four corner marks with pencil lines. The edge of the
template is used as a straight edge.
2. DRILL HOLES
With the drill perpendicular to the panel, drill the
six "A" and "B" holes using a 3/16 inch drill. THE
SIX HOLES MUST BE DRILLED BEFORE MAKING
THE CUTOUT.
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