McIntosh MPI-4 MPI4 Maximum Performance Indicator Scope Oscilloscope NICE An Amazing Tool for Any System!! ! MUST SEE!!! 

  

McIntosh MPI-4 MPI4 Maximum Performance Indicator Scope  

In the mid 1940’s Frank McIntosh headed a small firm specializing in the design and development of radio and broadcast stations. Being on the forefront of this burgeoning industry he saw the many shortcomings of the professional equipment of the day. Most notably was the need for high-powered, low distortion amplifier.  Hiring engineer Gordon Gow as his assistant the duo researched and developed a landmark amplifier. The amplifier was so far superior in output and distortion specs it was at first met with disbelief. The audio test equipment of the day was not designed to test an amp of such exceeding performance characteristics. But the proof was in its performance. Word of mouth spread and demand grew thus Frank McIntosh & Gordon Gow had new day jobs and McIntosh Laboratory was born. Hindsight confirms the company introduced a new era of professional audio excellence and they were amongst the first to market professional equipment to the consumer. Thus nurturing the high-fidelity industry and spearheading it for years to come.

For more than six decades McIntosh has maintained dominance in the high-end audio industry. They are the only surviving “foundational” high fidelity equipment manufacturer around today, still headquartered in Binghamton, New York, with operation and manufacturing carried out in the same method of the originators.  McIntosh’s permanence in the marketplace is owed to its history of phenomenal components, all adhering to the same design criterion set forth by Frank McIntosh and Gordon Gow; superior sonic performance and unmatched reliability. Every component was created with capacity so great that it will never be operated at or near its stress point.  A good reason why an estimated 80% of the McIntosh components produced since 1949 are still in use today and what’s more amazing is these same components are outperforming modern counterparts with the benefit of years of technological progression.  When you buy a McIntosh you’re buying a lifetime component!

The McIntosh MPI4  Maximum Performance Indicator was created in 1973 with a production run until 1977. It was a fairly expensive piece in its day, therefore relatively few MPI-4’s are around today.

  The McIntosh MPI-4 is an elaborate, yet compact, laboratory grade instrument that allows you to maximize the performance of your complete audio system and individual components. It continuously monitorsthe quality of the performance of astereo system. It can sample and display signals from the tuner, preamplifier and power amplifier without reconnecting cables.

As a tuning aid exact FM stationselection and precise tuning is seen.Displays of FM are signal strength,modulation percentage and multipathinterference; of audio signals arestereo balance, amplitude, phase andchannel separation. Output power ofthe power amplifier can be seen atany instant during program performance, or stored to develop a trendover several minutes. With the addition of test records, the MPI 4 canshow compliance and trackabilily of a phono pickup, frequency responseof the preamplifier and power amplifier, audio distortion and stereospeaker balance. In the dual tracemode, the left and right stereo channels appear simultaneously and separately on the screen for direct comparison.The MPI-4 is, even in this day, an extremely useful tool that provides valuable information which in-turn allows you to improve your system considerably. Some of its many features and functions include:
 

Each channel of stereo signal is displayedindividually in the dual trace mode of opera-tion. Comparison of the signals assists incomparison of recordings, the quality ofstereo information in the source and muchother valuable information.

 

• Level
  The audio level of stereo signals is displayed as two vertical columns on thescreen. The height of each column is determined by the power or amplitude of theinput signal.Action can be stopped and held to permitclose comparison between the highestlevels attained by left and right channels.

   

• Phono Cart Calibration
     You will protect your record investment,extend the life of your records, and reduceneedle wear when the turntable is properlyset up. With the aid of test recordings theMPI 4 will assist in this proper set up. Thedisplay assists in properly adjusting forproper tracking force, best tracing vs tracking force, anti-skate, proper phasing, andchannel separation.

   

• FM Tuning
     You\'ll see signal strength, center channelFM tuning and a reference for multipathdistortion elimination. The image is a display of the tuner IF curve. Signal strength isthe vertical axis. Horizontal center is thecenter of the detector and IF curves. Propertuning gives minimum distortion and maximum listening pleasure on all kinds of FMbroadcasts.

     

• 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 theMPI 4 you can see the phase relationship soyou can correct the condition.

   

• Balance
       Accurate system balance assures you offull stereo pleasure, The MPI 4 gives you avisual indication of the balance of yourstereo system. You can check and correctthe output balance of your stereo phonocartridge, tape recorder, tuner, or any partof your stereo system. You will know whenyour stereo system is in balance when youuse an MPI 4.

• Channel Separation
         The MPI 4 shows the stereo separationfrom all stereo program material. The display changes position and shape with theprogram material to permit interpretationof what the display means to your listeningenjoyment. You see what makes a goodstereo record sound good. You will knowwhy your records sound the way they do.

   

• Multipath Display
         Multipath reception deprives you of FMlistening 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

       

• And Much More!

         

   

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 inputSignal
In the single trace mode it is triggered by the displayed waveformIn the dual trace mode the trigger is selectable. Left channel, rightchannel, or line frequency Level Indication Normal; 250 µs rise time500 ms decay time
Peak: 500 ms use time25 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 preventphosphor damage Semiconductor Complement
2 integrated circuits
23 transistors
10 light emitting diodes Power Supplies Regulated to give equivalent performance for line voltages of 100 to135 volts Power Requirements 120 volts, 50/60 Hz, 50 watts Dimensions 16” W x 14 1/4” D x 5 1/2” H Weight 18 lbs unpacked

Scope has been tested and is operating without problem, all features and functions are working. Cosmetically it shows some ware. There is a small dent on top cover. The black top on pushbutton “power amp” located on rear of unit is missing, still functional. There are scratches and nicks on frame and end caps. The black frame was touched up by a previous owner. There are a couple bubbles on faceplate. Some scratches and ware on chassis. 

This is a sale so it will go to the highest buyer. Winning buyer pays $45.75 for careful shipping, packaging, & insurance in the continental U.S.
International buyers welcome and pay only actual shipping price, no handling fee.Please note: the item pictured is guaranteed to be the actual item you will receive. None of my pictures are taken off other peoples pages or web sites, so offer with confidence - what you see is what you get! PayPal and any other approved payments gladly accepted! (please email for details) Never a handling fee, buyer pays actual shipping as stated above.

International buyers welcome.

Click here to check out my other sales for more great items! to view supersized image
Click to view supersized image
Click to view supersized image
Click to view supersized image
Click to view supersized image
Click to view supersized image
Click to view supersized image
Click to view supersized image
Click to view supersized image