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The MPI 4 is a laboratory-grade instrument. It continuously monitors
the quality of the performance of a
stereo system. It can sample and display signals from the tuner, preamplifier and power amplifier without reconnecting cables.
As a tuning aid exact FM station
selection and precise tuning is seen.
Displays of FM are signal strength,
modulation percentage and multipath
interference; of audio signals are
stereo balance, amplitude, 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 trackabilily of
a phono pickup, frequency response
of the preamplifier and power amplifier, audio distortion and stereo
speaker balance. In the dual trace
mode, the left and right stereo channels appear simultaneously and separately on the screen for direct comparison.
In short, the MPI 4 is a professional
measuring instrument that assures
you continuously that your system is
performing as expected. You never
again need to wonder about the performance of your stereo.
MAXIMUM
PERFORMANCE
INDICATOR
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• maximum performance from your stereo system •"once in
• a view of the separation provided on any signal source
• absolute balance of your stereo channels from phono cart
DUAL TRACE
Each channel of stereo signal is displayed
individually in the dual trace mode of operation. Comparison of the signals assists in
comparison of recordings, the quality of
stereo information in the source and much
other valuable information.
The MPI4
LEVEL
The audio level of stereo signals is displayed as two vertical columns on the
screen. The height of each column is determined by the power or amplitude of the
input signal.
Action can be stopped and held to permit
close comparison between the highest
levels attained by left and right channels.
PHONO CARTRIDGE CALIBRATION
You will protect your record investment,
extend the life of your records, and reduce
needle wear when the turntable is properly
set up. With the aid of test recordings the
MPI 4 will assist in this proper set up. The
display assists in properly adjusting for
proper tracking force, best tracing vs tracking force, anti-skate, proper phasing, and
channel separation.
FM TUNING
You'll see signal strength, center channel
FM tuning and a reference for multipath
distortion elimination. The image is a display of the tuner IF curve. Signal strength is
the vertical axis. Horizontal center is the
center of the detector and IF curves. Proper
tuning gives minimum distortion and maximum listening pleasure on all kinds of FM
broadcasts.
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helps you
lifetime"programs flawlessly recorded • better FM reception
• a measurement of the performance of the phono cartridge
dge to speakers • an accurate measurement of power output
PHASE
Program material that is 'out of phase'
sounds unnatural and thin; 'in phase'
sounds alive and rich. Occasionally a program source will be 'out of phase.' On the
MPI 4 you can see the phase relationship so
you can correct the condition.
BALANCE
Accurate system balance assures you of
full stereo pleasure, The MPI 4 gives you a
visual indication of the balance of your
stereo system. You can check and correct
the output balance of your stereo phono
cartridge, tape recorder, tuner, or any part
of your stereo system. You will know when
your stereo system is in balance when you
use an MPI 4.
$599.00 Cabinet $29.00
CHANNEL SEPARATION
The MPI 4 shows the stereo separation
from all stereo program material. The dis-
play changes position and shape with the
program material to permit interpretation
of what the display means to your listening
enjoyment. You see what makes a good
stereo record sound good. You will know
why your records sound the way they do.
MULTIPATH DISPLAY
Multipath reception deprives you of FM
listening enjoyment in several ways:
• noise level increase
• distortion is introduced into the program material
• stereo separation is reduced
• the stereo effect may be completely lost
• stereo indicators may fail to function
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MPI 4 Performance Limits
Our Promise to You
Performance Limits are the maximum deviation from perfection permitted for a Mclntosh instrument. We promise you that your MPI 4 must be
capable of performance at or exceeding these limits or you get your money
back. Mclntosh is the only manufacturer that makes this guarantee.
MULTIPATH
Sensitivity: 100 rnV/cm
Frequency Response: DC to 50,000 Hz [-3 dB)
Input Impedance: 250,000 ohms
Signal Strength Polarity: Selectable positive or negative
STEREO
Sensitivity-L (Vertical Amp,): 1,75 mV RMS/cm (5 mV P-P/cm)
-R (Horizontal Amp.): 1.75 mV RMS/cm (5 mV P-P/cm)
Frequency Response: 5 Hz to 50,000 Hz (-3 dB)
Input Impedance: 250,000 ohms
POWER LEVEL
Sensitivity: 0.1 to 1000 watts continuous for full scale indication (+3 dB)
in 9 calibrated steps
Frequency Response: 5 Hz to 100,000 Hz (-3 dB)
Input Impedance: 75.000 ohms
Calibration: For bridging 4, 8 or 16 ohm speaker loads
PREAMP LEVEL
Sensitivity: 15 mV RMS for +3 dB indication
Frequency Response: 5 Hz to 50,000 Hz
Input Impedance. 250,000 ohms
SWEEP
Display modes: Left, right, or both (dual trace)
Sensitivity: 1.6 mV RMS/cm (4.5 mV P-P/cm)
Frequency Response: 5 Hz to 50,000 Hz (-3 dB)
Input Impedance: 250,000 ohms
Sweep Frequency: 20 Hz to 20,000 Hz in 3 decade ranges
Sweep Expansion: 0.25X to 5X
Sweep Trigger: The sweep is triggered only in the presence of an input
signal
In the single trace mode it is triggered by the displayed waveform
In the dual trace mode the trigger is selectable. Left channel, right
channel, or line frequency
LEVEL INDICATION
Normal; 250 µs rise time
500 ms decay time
Peak: 500 ms use time
25 sec decay time
Reset: Manual
LOW PASS FILTER
16,000 Hz L F Filter for stereo and sweep modes
19,000 Hz and 35,000 Hz rejected by at least 30 dB
RETICLE LIGHTING
Selectable: On-Off
CATHODE RAY TUBE
3 inch tube, calibrated 5 x 6 cm
1000 volt accelerating potential
AUTOMATIC INTENSITY CONTROL
In the absence of a horizontal signal, the intensity is reduced to prevent
phosphor damage
SEMICONDUCTOR COMPLEMENT
2 integrated circuits
23 transistors
10 light emitting diodes
29 diodes
POWER SUPPLIES
Regulated to give equivalent performance for line voltages of 100 to
135 volts
POWER REQUIREMENTS
120 volts, 50/60 Hz, 50 watts
SIZE:
Front panel measures 16 inches wide (40.65 cm) by 5-7/16 inches
high (13.8 cm). Chassis measures 15 inches wide (38.1 cm) by 5
inches high (12.7 cm) by 13 inches deep (33.1 cm) including PANLOC
mounting brackets and back panel connectors. Knob clearance required is 1-1/2 inches (3.85 cm) in front of the mounting panel
FINISH:
Front panel is anodized gold and black with special gold/teal nomencla-
ture illumination. Chassis is black
MOUNTING:
Exclusive Mclntosh developed professional PANLOC
WEIGHT:
21 pounds (9.55 kg) net, 33 pounds (15 kg) in shipping carton
YOU SHOULD OWN MclNTOSH BECAUSE
• Mclntosh instruments are designed and manufactured for long life.
• Mclntosh instruments have always been designed for long lite with
low maintenance costs and high quality performance. Mclntosh instruments have been and are the LABORATORY STANDARD for the
world. Until 1949 the performance requirements for a Mclntosh had
long been an engineering dream. They became a reality with the introduction of the first Mclntosh amplifier. Through all these years Mclntosh has produced instruments that have exceptionally long life.
Regardless of age, most Mclntosh instruments are still in use today.
Amplifier clinics held all over North America have shown that most
of the Mclntosh instruments ever manufactured are still in service
today and still meet or exceed original exacting requirements for
performance that were required of them when new.
• Used Mclntosh instruments enjoy the highest resale value in this
field. Retailers report that customers are constantly searching for
used Mclntosh instruments. A Mclntosh does not remain on the
"Used" display long. You'll get more when you trade-in your Mclntosh assuring you of maximum return on your investment.
Franchised Dealer
AUDIO CLASSICS, LTD.
www.audioclassi
3501 Old Vestal Road, Vestal, NY 13850
Fax/Phone: 607-766-3501
cs.com
• Mclntosh dedication, not only to improvements, but also to fundamentals, has justified many patents on refinements as well as basic
circuit structures.
• The size of the Mclntosh, investment in professional testing instruments bears eloquent testimony to the commitment to acquire knowledge for the benefit of our customers. On a percentage basis Mclntosh probably invests more of its sales dollars in testing facilities
than anyone else in a like business. As new testing instruments are
produced that update the Mclntosh ability to know, Mclntosh invests
in them ... wave form analyzers—real time analyzers—low distortion signal generators, etc. Only through this impressive investment,
through continuous testing and research, through product analysis,
and endless measurement can Mclntosh promise and deliver to you
reliability, long life, performance, highest value, and freedom from
service.
• Since its beginning in 1949, Mclntosh Laboratory has had the same
ownership and management. Mclntosh is the only company in this
industry that has had this kind of history. Mclntosh has been and is
still dedicated to the best possible values.
• Doesn't it make good sense to deal with a company that wants to
do as much for you as it possibly can?
Laboratory Inc.
2 Chambers St., Binghamton, N.Y. 139O3
Phone area 6O7 723-3512
038-763
BE042003
Primed in U.S.A.
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