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Understanding Phono Cartridges

   There are many different types of phono cartridge. But all have a three things in common.

  • Stylus Cantilever
  • Stylus Suspension
  • Stylus tip

During the technological hi fi boom 1974-1984, there were specifications that helped define cartridge performance. Today, only a few cartridge makers offer specs, most have stopped. The reason specs are important, beyond the obviousness of product comparison, is that they hold the maker to a specific quality, fit and finish. If a maker does not tell you the profile of the diamond for example, then nothing stops that maker from using different profiles as he sees fit. There is no guarantee that the cartridge you buy is the same as the one you just read a review on. So if you really want to be sure you are upgrading, demand specifications.

Now, what specs are important.
  • Stylus effective tip mass. This is the weight of the diamond tip, cantilever and the active element on the other end be it iron, magnet, or coil. The higher this figure, the poorer the hi frequency tracking ability. 0.4miligram should be the highest amount for a truly hi end cartridge. Hold a 1 pound weight in both hands with arms extended and try swinging it back and forth quickly. Now you understand what the groove is doing to your stylus assembly. At the height of the technological hi fi boom values as low as 0.17mG were acheived and 0.3mG were common.

  • Stylus Compliance. This is the springiness of the stylus suspension. The compliance, along with the effective mass of the tonearm, will determine the low frequency resonance of your arm/cartridge. Drop a stone on a spring and it bounces up and down. That is what happens when the stylus encounters a warp in the records surface. it bounces. You have probably seen your speakers moving in and out to this rhythm. If the resonance is too low, The stylus will hop right out of the groove, if it is too high, then deep bass frequencies will be affected. With most tonearms today, compliances less than 15 should be avoided. Keep in mind that the lower the compliance the stiffer the suspension; IE the more work the groove must do to wiggle that stylus back and forth. It is a measure of both groovewear and resolution. At the height of the technological hi fi boom, compliances of 20-30 were common. A note to unipivot tonearm users. These arms, abandoned in the fifties because of their lack of lateral stability, have made a comeback. Consult with the maker, for the normal rules of compliance matching do not apply to these arms. you may need a stiff suspension to avoid serious woofer pumping on warps.

  • Stylus Profile. This is the shape of the diamond as it contacts the groove. There are many different shapes and they are all borne of historical evolution.

    -The conical or spherical stylus is the simplest and is common on inexpensive players. It is the least resolving since it cannot trace the highest frequencies in the inner grooves.

    -The Elliptical stylus contacts the groove with a narrower footprint and improves high frequency performance in the inner grooves. But for a given tracking force it will produce greater groove wear.

    -The Line contact stylus, borne out of the discrete quadraphonic era, has a narrow and long footprint. It is the highest resolving stylus design. And since it distributes the force along a line it exhibits less groove wear and longer stylus life. If there is a downside, it is that with worn records, this stylus will read more of the record wear. For your worn records, you may want to have an elliptical or even a sphercal stylus for them. An alternate view uses a line contact stylus on a stiff suspension that tracks heavy. This pushes the stylus into the vinyl and makes fine surface defects less audible. Of course heavy tracking forces accelerate groove wear and raise the resonant frequency. I would reserve this approach for the most worn records.

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