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McIntosh MPI-4 Tuner Maximum Performance Indicator

Sale price£0.00
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Pickup currently unavailable at SkyFi 479

Mcintosh Mpi-4 Tuner Maximum Performance Indicator

McIntosh MPI-4 Tuner Maximum Performance Indicator

SkyFi 479

Pickup currently unavailable

479 South Broad Street
Glen Rock NJ 07452
United States


This is a Super Clean survivor condition piece, featuring impeccable glass and cosmetics at nearly 45 years "young"!

Tested, serviced, and working as it should. The oscilloscope tube is super bright and sharp.

A great match to your vintage McIntosh tuner, and the focal point of your system for you and your guests.

More from McIntosh on this unique piece from our McIntosh Collection:

The MPI 4 is a laboratory-grade instrument. It provides the facility to continuously monitor the quality of the performance of a stereo system. The MPI 4 can sample and display signals from the tuner, preamplifier and power amplifier without reconnecting cables. Signals are displays 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 balance, 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 simultaneously and separately on the screen for direct comparison. The instrument also has "triggered sweep." It permits the viewer to choose a single tone and lock it on the screen for careful inspection.

Click here for a PDF copy of the MPI-4 Original Sales Brochure

Click here for a PDF copy of the MPI-4 Owner's Manual

Click here for a PDF copy of the MPI-4 Service Manual

Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.



Original Box



Yes and Online




Yes - Power

Physical Condition


Working Condition


SKU: 101088