Phono Cartridge Reviews

The Shure Brothers have been making magnetic cartridges since the early 1950s (they had been exclusively microphone manufacturers prior to then), and their continuing R&D program has resulted in new, improved models every few years rather than every 6 months (as seems to be the rule these days). As a result, Shure has the appearance, to most audiophiles, of a stodgy, plodding, rather "establishment" manufacturer that can be trusted to make a solid, reliable product but nothing brilliantly innovative or—for that matter—nothing remarkably good either.

To be sure (Sorry about that!), the firm is locked into a design principle—the moving-magnet transducing system—which is at present enjoying a period of public scorn, due to the theoretical advantages that moving-coil designs would seem to offer. But Shure's designers have felt that, as long as existing cartridges were unable to trace certain groove modulations cleanly, and were exacerbating their mis-tracking with high-end peaks, there was room for substantial improvement of the moving-magnet design, as old-hat as it may be. They may, finally, have improved themselves out of the R&D business with the V15-IV.

Readers accustomed to seeing the pickup reports in High Fidelity and Stereo Review may not realize how truly rotten most cartridges are, even in these days of new "state-of-the-art" components every month. Most available cartridges, including virtually every moving-coil design, have a characteristic brightness-range (circa 5kHz) suckout, topped off by a high-end peak of anywhere from 2 to 6dB. The fact that, despite such flaws, most of these can be mated to an equally flawed system that will make them sound "good" cannot alter the fact that they are inaccurate transducers. Add to this the unarguable fact that most audiophiles have no more frame of reference for judging sound than "I-like-it" or "I-hate-it," and it is easy to understand why cartridges (and loudspeakers) are the sources of the widest disagreement among audiophiles today.

An octave (or narrower-band) equalizer can be used to illustrate what a small brightness suckout and high-end peak will do to the sound. First, set its controls to approximate the curve in fig.1, which complements the response of most current cartridges. (Check your equalizer's instructions for the correlation between control settings and decibel values.) Then switch the equalizer In and Out while listening, and observe how much difference these "slight" deviations make.

If your present cartridge sounds "good" to you now, those small deviations in response will more than likely make it sound worse, in precisely those ways that have been the basis of criticisms of the Shure. Instrumental sounds will be brighter (more forward), thus diminishing the impression of depth and "perspective." And there will be less high-end "air," because of the relative reduction in response above 10kHz.

The V15-IV approaches the ideal flat response more closely than any other cartridge we know of. Its "lack of depth" is in actuality a failure to exaggerate depth; its lack of "air" is merely a failure to compensate for the tendency of most speaker systems to dull the extreme high end. There are two versions of the V15-IV available: The standard version with an elliptical stylus, and the V15-IVG version with a spherical stylus. The elliptical, with its smaller contact radii, is better able to "resolve" very–short-wavelength (high-frequency) groove modulations, and thus has rather better high-frequency response than does the G version. (See fig.2.) The elliptical is, in theory at least, a more accurate reproducer of recorded high-frequency information than is the spherical. In terms of listenability, though, the elliptical-stylus version has been found to have a somewhat "hot" high end; all of our auditioners indicated a preference for the spherical, despite its theoretical inferiority.

Shure Brothers recommends a total of 300pF of capacitance in parallel with each output from the V15-IV. We did not find this to be necessary with either the standard elliptical model or with the spherical, for even with 75pF capacitance, both were within ±dB out to 20kHz. (This is in marked contrast to earlier V15s, which exhibited a pronounced dip/peak with capacitances of less than 200pF.) We did find, however, that parallel capacitance totalling around 300pF produced a somewhat flatter response, and the curves in fig.2 were run with that value, as representing the flattest response we were able to obtain with the cartridge. With that capacitance, we found it difficult to distinguish the sound of the V15-IVG from that of some tapes that had been used to master the discs.

This was as true of other aspects of the sound (depth, stereo imaging) as it was of colorational considerations. We have found other cartridges that were capable of producing more natural-sounding musical reproduction with certain specific speaker systems in certain specific acoustical surroundings, but none of those could make discs sound quite as much like the original master tapes they had been made from. In other words, while some other cartridge may be your best choice, for your system in your listening room, the Shure V-15IVG has the potential for being as accurate a cartridge as is available today.

We say "potential" because its sound will of course be influenced by the tonearm and preamp as well as, to a lesser extent, the turntable. Our tests were conducted with the SME 3009-III arm, the Berning TF-10 preamp, and an acoustically isolated Denon DP-2000 turntable.

The Damping Brush
The V15-IV is equipped with a small, fine-bristled brush mounted directly in front of the stylus and pivoted via damped hinges. The pickup can be used either with the brush raised and locked out of the way, or lowered so that the brush rides in the grooves. The brush is supposed to serve two purposes: To hold the cartridge directly over the average groove path, and to absorb warped-disc undulations. The result is a reduction in inward pull (due to the arm's offset angle), effective damping of the arm/cartridge resonance in both the horizontal and vertical planes, and reduction of spurious subsonic interference as a result of warps and groove eccentricities. Not surprisingly, it is highly effective in accomplishing its goals; surprisingly perhaps, it does these things without producing a trace of background noise due to the brush's contact with the disc—normally.

One abnormal condition can cause it to produce a barely audible midrange scrape, and it is a condition we have encountered in other cartridges, too: A flapping stylus block.

If the front part of the stylus assembly does not seat firmly against the underside of the cartridge body, it will tend to flap when subjected to any vibration, producing an irritating high-end ringing resonance along with the sound, and exaggerating surface noise. Two samples of the V15-IV that we encountered had this problem, which is readily diagnosed by tapping the headshell with the fingernail (at a normal playback-volume setting) while alternately grasping and releasing the sides of the stylus assembly. If there is an audible change in the sound when you hold the stylus block, it's flapping.

The simple solution: Take two small (1/8" diameter) wads of Duxseal or Mortite gunk, and press one onto each side of the stylus assembly where it abuts the body of the cartridge (fig.3).

The effects of the damper brush are audible to a degree that depends largely on how well damped the tonearm is. In an undamped arm, the overall sound is noticeably cleaner, bass is markedly tighter, and imaging is somewhat improved. The changes in low-end resonance and warp-induced subsonic interference are readily measurable, too, as shown in fig.4. In a well-damped tonearm such as the Hadcock or the SME Series III, the damper brush has no measurable effect on the bass resonance and only a slight effect on subsonic interference, but it has a definite effect on the sound, which becomes perceptibly cleaner overall when the brush is in use.

Our suggestion: Use it, but do keep it clean. One of those little stylus brushes that resembles a miniature toothbrush is ideal for the cleaning.

Magnets vs Coils
A propos the moving-magnet/moving-coil disputation, we call readers' attention to some interesting findings on the subject by researcher/designer John Curl (footnote 1). His measurements showed that, while most moving-magnet cartridges are bandwidth-filtered to an upper limit of between 25kHz and 40kHz (because of the natural low-pass filtering effect of cable capacitance in parallel with a fairly high internal-generator inductance), many moving-coil types produce substantial amounts of output energy as far out as 150kHz.

While it can be argued that this demonstrates the transient superiority of moving-coil cartridges, there is no arguing, either, about the fact that that ultrasonic energy—not having been present in the original signal source—must therefore represent spurious distortion products of the particular kind that even the best playback electron™ ics are going to have trouble coping with. There is in fact strong evidence now to suggest that what was supposed to be an advantage of moving-coil designs—their lack of longitudinal stylus motion—is in fact a major reason why they produce such strong ultrasonic impulses. More about that in a later issue, though.

Summing Up
There are undoubtedly a number of other cartridges which will do audiophile-type things better than the Shure. Some have better transient attack, some will seem to image better through some speakers (and not as well through others), while some may have marginally better trackability through the middle range. Which is another way of saying that the typical audiophile, who has no fault to find with the midrange reproduction of most components, will almost certainly be able to find another cartridge that pleases him more than the V15-IVG.

But the person who merely (!) wants a cartridge that will reproduce what was originally inscribed on his discs may never again feel the need for a better cartridge than this one. Perhaps the most telling story about the much-maligned V15-IV emerged during the course of an interview with Stan Ricker (who does half-speed cutting for some of the audiophile disc manufacturers, footnote 2) that appeared in one of the perfectionist-underground audio magazines that had panned the V15-IV for glaring deficiencies.

During the course of the interview, Mr. Ricker allowed the interviewer (a regular contributor to that magazine) to compare the sound of an original tape with its lacquer-disc playback. The writer duly reported that he had considerable difficulty telling which was which—The playback cartridge was the V15-IV.

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Footnote 1: "Omitted Factors In Audio Design," Audio, September 1979.—J. Gordon Holt

Footnote 2: In the 1970s, Stan Ricker had engineered my favorite recording of the Ravel String Quartet, with the Sequoia Quartet for Delos. In 1996, Stan cut the master for Robert Silverman's Sonata: Piano Works by Franz Liszt (LP, Stereophile STPH008-1) still available from the "Shop" page on this website.—John Atkinson