Stylus Wear in Vinyl LP Playback- Mike Bodell’s “The Finish Line for Your Phonograph Stylus”
One thing all of us who play vinyl LPs share, no matter how basic or esoteric the turntable/tonearm and phono stage, is our reliance on the phono cartridge. These intriguing little devices not only make a significant contribution to the sound quality we experience, but are the first interface with the record, functioning as a transducer to convert tiny inscriptions in the groove into an electrical signal that eventually gets equalized, amplified and re-transduced from an electrical signal to a mechanical one at the loudspeaker. The stylus is the point of contact most likely to wear due to friction and its lifespan may be far shorter than most believe.
We benefit from far more information and more sophisticated tools for set-up today than in the heyday of the LP. Record cleaning plays a more widely accepted role with a greater range of products available to maintain our records (and to a degree, the stylus itself). With the resurgence of “vinyl” at almost all levels, from basic entry level gear to the cost “no object” turntables, tone arms and cartridges, we really are in a “golden age” for vinyl playback—more can be extracted from the grooves of records old and new and there is, via the Internet, a wealth of information that is readily available to users.
This rebirth in the record playing market, though it may, in its entirety, be just a small bump in the larger world of consumer electronics, has generated a lot of discussion on the Internet about set up, inner groove distortion, null points, overhang, mass, tracking force, anti-skate, compliance, stylus rake angle, vertical tracking angle and a host of other issues that involve the cartridge/tone arm set up.
But apart from generally accepted wisdom on different stylus shapes, there seems to be little concrete information on stylus wear. Many of the studies were performed decades ago, when playing records was a mainstream medium and developments in stereo playback were rapid. When the cost of an average phono cartridge was quite modest by today’s standards, the issue of wear was probably a subject of interest only to engineers and those deeply involved in cartridge or record manufacture.
Today, the vinyl market is flourishing while still a niche in audio. Most of us invest in the best gear we can afford and presumably focus some attention on proper set up at the outset, sometimes relying on a dealer or third party specialist to mount and align the cartridge and make the appropriate settings on the tonearm. After that, unless you are deeply involved in experimenting with cartridges, tone arms and set-up parameters, most of us just expect to enjoy the results, with the occasional worry about mistracking: bad record or something wrong with the cartridge or set up?
Over the years I have become more obsessive not only about cleaning records, but making sure the stylus is clean. I would (and still do) check that the cantilever appears straight, but have little ability to ascertain stylus wear. Barring outright failure of the electro-mechanical system of the cartridge itself (a rare event) or catastrophic damage from a bent cantilever (the “cleaning lady” is always to blame), we soldier on in the expectation that our cartridge will live a long life and only be replaced as necessary.
This is less of an issue for more modest moving magnet cartridges with relatively inexpensive user replaceable styli assemblies. It becomes an ordeal with expensive moving coil cartridges that require manufacturer (or third party) retipping or rebuilding. Unless you have a local dealer capable of examining the stylus, most of us are out of commission or run another cartridge as an alternative when the little bejeweled beast is sent off for inspection or more.
Mike Bodell, who contributed that wonderful article about the history of ultrasonic record cleaning here, has written a well-researched and important study on stylus wear. It happens that Mike knows a little about rocks and the molecular structure of diamonds because he was a geologist by profession. He is also a long-time audiophile with the sort of burning desire to get to the bottom of questions most of us would not research in the depth he does.
When Mike brought up the idea of an article about stylus wear, it not only intrigued me as a subject worth exploring but also coincided with my own quest to learn more about the behavior of different cartridges (and tone arms) in my system.
Although I was approaching the subject from a sonics and tracking performance perspective, Mike’s work—which he shared with me—was not just fascinating, but a little disturbing. It suggested that stylus wear can occur far earlier than is generally believed and that there is a large zone of “unknown” between very conservative evaluations of stylus life and the point when a stylus ought to be replaced. I’m not sure it gave me comfort, but it did add considerably to my knowledge about what was going on at the microscopic level of “first contact.” I had already been developing more rigorous set up techniques and using additional tools to recheck my work under better light and magnification. As a result of reading Mike’s article, I am now starting to keep track of the actual hours of playing time (something that I previously dismissed as too OCD, but is pretty easy to do with a tally counter and some averaging for the playing time of a record side).
If the cartridge needs work, retips or rebuilds by the original manufacturer are considered preferable if only to preserve the economic value of the cartridge. And, it is certainly worth checking first with your cartridge manufacturer, no matter what route you go. However, there are some pretty serious third parties out there known for quality work; some are legendary. See the separate list here for a list of third party cartridge retippers/rebuilders.
Mike’s paper is an important contribution to the literature and I’m honored to publish it here. His conclusions—that stylus wear has been established to occur much earlier than the outside limit often claimed for stylus life—compel us as users to better monitor what is happening with the stylus at a far earlier point than obvious mistracking or distortion, when damage may already be done.
It also compels cartridge manufacturers to make information about stylus life more accessible. I’m sure there are many variables that could come into play, including proper set up and alignment at the outset. But assuming that a top notch set up was performed at the outset (see a forthcoming article devoted to this subject), and that some care is taken to clean both stylus and records, what are the realistic expectations for users? Mike asks this question from a number of different vantage points, from microscopic examination of the stylus, to noticeable deterioration in sonic performance, to number of hours of use. The problem, of course, is that the degradation in sonic performance is usually incremental and hard to discern until it may be too late. Apart from the information Mike was able to glean from various empirical studies and anecdotal reports, he calls upon cartridge manufacturers to supply us with more information based upon their work in designing, testing and repairing or retipping the cartridges they supply.
Granted, the vast majority of cartridge manufacturers rely on other entities to supply the diamond stylus. And though there may be some proprietary aspects to the design and know-how involved in building their cartridges, the manufacturers are in the best position to advise on life of the stylus, taking into account other factors, like mass, compliance and stylus pressure. The choice of stylus shape seems to be less of a factor in longevity according to Mike’s research, but if a more exotic shape contacts the groove with more surface area, how does microscopically verifiable wear manifest itself with these shapes?
Some of the more extensive published testing on the effect of stylus wear was performed long ago. As the vinyl playback market contracted after the introduction of the CD, there seemed to be less commercial interest in phono cartridges, with lower demand and a commensurate reduction in the attention paid to the subject by the audio engineering community at large. But the renaissance of vinyl and associated equipment has brought with it a vigorous demand for these products, many of which are far more sophisticated, employing more exotic materials and design techniques for the cartridge itself, along with higher prices. Measurement and testing equipment and methods ought to be better than what was available 60 years ago. This information is surely obtainable and manufacturers should be in the best position to supply it. I had one hurried conversation with a well-known cartridge retipper who also introduced another factor—jitter—that could contribute to stylus longevity, a subject that we may be able to pursue in greater depth in another article.
Although Mike entitles it the “finish line,” the stylus is really where it all starts on LP playback. And Mike’s article is probably the best place to begin if you play records.