McIntosh MR78 Analog Tuner - Legendary Serviced in 2023

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General:
Many enthusiasts consider the McIntosh MR78 to be the finest FM tuner ever made.

In our opinion, it is unquestionably among the top five. Its performance, selectivity, and sound quality remain exceptional even by today’s standards, outperforming the vast majority of tuners from its era.

This particular MR78 was professionally serviced in 2023 and features new factory McIntosh front glass, giving the tuner an especially clean and striking appearance. For those seeking the complete vintage presentation, we can also supply a perfectly fitting McIntosh wood cabinet — please contact us for availability and details.

All functions were thoroughly tested in our lab, where the tuner performed beautifully. It was also carefully inspected by our in-house technician to ensure proper operation.

Included with the tuner are an original McIntosh box for safe shipping, the original bezel, and the owner’s manual.

The MR78 was such a significant achievement in audio engineering that it was later featured in the Consumer Electronics Hall of Fame, which described it as:
“A young engineering genius used a computer to design a filter and the result was the greatest FM tuner ever built.”
That engineering genius was Richard Modafferi, whose initials reversed (“MR”) became the model prefix for a long line of legendary McIntosh tuners.

SkyFi Cosmetic Notes:
The faceplate on this unit has been replaced with a modern production piece from the McIntosh factory. The lighting has been updated to LED to improve the light propagation which is affected by the glass replacement. The original trim bezel was removed during the glass replacement but is included with the sale if you would like to put it back on in the future. The power cord was also replaced. Overall condition is excellent.

SkyFi Technical Notes:
This MR78 was serviced by Analog Sound Labs in 2023. The majority of the capacitors in the unit were replaced. Select transistors replaced as needed, and a full alignment was completed. We double checked the alignment and performance in our lab. All features work as designed, dial tracking, sensitivity, and MPX performance are all solid. If you have been in the market for an MR78 this unit would be an excellent pick.

Brand Background:
McIntosh Laboratory is an American manufacturer of handcrafted high-end audio equipment based in Binghamton, New York. The company was founded in 1949 by Frank McIntosh. The company designs and produces audio amplifiers, stereo tuners and other consumer electronics products.

Ownership:
Second Owner

Connections:
RCA output, 75ohm antenna output, 300ohm antenna output, AC outlet

General Sound:
Smooth, uncolored, undistorted natural and clean

Cosmetic Condition:
7/10 = Good. One or two minor scratches. Well Maintained. See our detailed rating description here.

Working Condition:
Working perfectly and tested in our lab.

Included:
Unit and box, captive power cord, manual, bezel

Packing:
Original Manufacturers Packing

Specs:
Type: Mono/Stereo Tuner
Tuning Bands: FM
Tuning Scale: Analogue
FM Tuning Range: 88 to 108 MHz
Sensitivity: 2.5uV (FM)
Signal to Noise Ratio: 75dB (FM)
Distortion: 0.2% (FM)
Selectivity: 55dB (FM)
Frequency response: 20Hz to 18kHz (FM)
Output: 2500mV
Dimensions: 16 x 5.5 x 13 inches

Dimensions:
16" x 5.5" x 13"

Weight:
27 lbs.

Approximate Age:
1978

Link to Manual:
Click Here

Recommended Cables:
Kimber Kable - RCA Interconnects - Better

Kimber Kable - RCA Interconnects - Best

Testing Process:
We start with a visual inspection of all internal components to make sure that there are no signs of heat stress or damage. Capacitors are checked for telltale signs of predictive failure including bulging, shrunken wrappers, or physical leakage. We also inspect the PCBs for discoloration from resistors or transistors that may have been running hot.

On vintage units we often spot check select capacitors for value and ESR. Vintage analog tuners also have moving parts related to the tuning gang and dial string. These parts are inspected for smooth operation.

If the unit passes visual inspection it is bench tested for a handful of key performance parameters using a Sencore SG80 AM/FM Stereo Analyzer. The SG80 allows us to “simulate” an ideal radio station using precision test signals instead of music. This device in conjunction with an oscilloscope allows us to properly evaluate the following parameters:

1) AM Reception (Where Applicable)
2) FM Mono Reception & Tuning Meter Function
3) FM MPX Reception (Stereo)
4) Dial Tracking: How accurately the tuner dial or display indicates the actual frequency of the broadcast being received.
5) Stereo Separation: A properly working stereo tuner will have minimal crosstalk between the left and right channel.
6) Sensitivity & Signal Strength Meter Function: By lowering the output of the SG80 we can simulate weak stations and determine how well the tuner will be able to pull in weak distant stations. This adjustment also helps us verify signal strength meter function.

If the tuner has acceptable performance related to the parameters above we connect the unit for listening tests with a simple dipole antenna. We listen for audio reproduction quality of local stations and evaluate how many stations the tuner can receive while we sweep through the dial.

We are looking to verify that the tuner can decode stereo on strong local broadcasts and pick up a wide variety of local stations at the bottom, middle, and top of the frequency band. At this point we also test convenience features such as muting, filters, built in oscilloscope function, etc.

We finish up with an extended listening test on our long term test rig. We tune in to a strong local station and monitor for drift over a minimum period of 2-3 hours.