Shure M91ED

The cartridge Shure's own advertising called "second best" - and meant as a compliment.

Overview

Shure built the M91ED as a Deluxe High Trackability cartridge, and its period advertising was candid about where it sat in the lineup. Shure's copy called the M91ED the "prince" to the V-15 Type II Improved's "king" - the second-best cartridge in the house, priced substantially below the flagship and openly positioned that way. Manufacturers don't often admit that in print. Buyers knew what they were getting, and what they were giving up.

What they gave up, per the same advertising, was the last increment of trackability. Shure's own comparison put the M91ED's overall trackability scores "very close but not quite" to the V-15's phenomenal figures. What they kept was a good chunk of the V-15's engineering: the same gem-quality diamond elliptical stylus tip, the same mass-decreasing "nude" stylus tip mounting, and a similar electromagnetic structure. The M91ED was built on the flagship's design principles at a lower price point. It was not a stripped-down budget part wearing a familiar badge.

The tracking figures tell the practical story. The M91ED tracked between ¾ and 1½ grams. That made it usable on a wide spread of tonearms from the mid-1970s, without the ultra-light, ultra-expensive arms the V-15 wanted to show its best. The cartridge was specified at a 20-20,000 Hz frequency response with 5.0 mV output and 25 dB channel separation, with an elliptical stylus measuring 0.2 x 0.7 mil. The V-15 Type III in the same period Heathkit catalog is listed at 10-25,000 Hz and 28 dB separation. So the M91ED gives up a bit of bandwidth and a few dB of separation. Those differences are real, but they don't announce themselves on a mid-fi system of the day.

The M91ED ended up in a lot of homes because of how it was sold. It was the default cartridge bundled with complete turntable systems across Heathkit's 1976 catalog - included with the B-I-C 920, 940, 960, and 980; the Dual 510 and 1249; and the AR-1500A and AR-29 receiver packages. Buyers could take the M91ED at no extra charge, step up to the V-15 Type III for $45 more, or pick an Audio-Technica AT-14Sa for $35. Sold on its own the M91ED listed at $59.95. That bundling put the cartridge on an enormous number of turntables, and M91EDs are still turning up in used decks four decades later.

Contemporary advertising leaned hard on the upgrade argument. High Fidelity (May 1975, p.71) framed the M91ED as the sensible middle step for listeners on a "temporary austerity program" - a way to improve a budget system over the cartridge that came in the box, without reaching all the way to V-15 money. The same campaign promised "high trackability with performance second only to the V-15 Type III." That's marketing, not an independent lab verdict.

Shure's advertising in HiFi-Stereo (September 1972, p.74) made the same case when the M91ED was newer. Every cartridge in the house was doomed to near-obscurity in the V-15's shadow, but the M91ED closed some of that gap, particularly on trackability, because it borrowed the flagship's design principles - including the nude-mounted gem-quality diamond stylus. A year later the company's HiFi-Stereo (September 1973, p.57) copy was still calling it "a prince of a cartridge."

The M91ED was engineered to track well at moderate forces, it was built to the same standard as Shure's best, and it was made in sufficient numbers that examples are still findable. It is not a V-15, and Shure never pretended it was. It delivered most of the flagship experience at a fraction of the price.