Controlling The Cantilever
In your stereo phono cartridge, the stylus which traces the groove is attached to a small arm, or cantilever, which transmits the stylus motion to the actual sensing mechanism.
The mounting of this cantilever is critical to the proper operation of the entire cartridge.
Easy Does It
While the cantilever should move readily as the stylus moves (high compliance) it must also have the proper restoring force to bring it back to a central position when there is no groove modulation. It should also have no tendency to vibrate more easily at one frequency than another (resonance), particularly at audible frequencies. With the small masses involved, this can be a particular problem at very high frequencies, resulting in peaked response.
Equal Opportunity Damping
In most stereo cartridges, control of cantilever motion is supplied by an elastic material surrounding the fulcrum. With Audio-Technica Dual Magnet cartridges, this is a radial damping ring which responds equally to motion in every plane. Thus damping is uniform regardless of relative channel signal strength or phase.
Hand Tuning
This radial damping ring is slightly compressed during cartridge construction to a specific value which is hand-tuned for each stylus assembly. Thus compliance and resonance control can be optimized, eliminating potential unit-to-unit variations common to less sophisticated designs. Output is unusually smooth, even well beyond the highest audible frequencies.
A Perfect Match
The exact compliance value for each cartridge model depends on its intended use.
For instance, an inexpensive cartridge meant for low-cost players should have relatively low compliance to assure proper tracking. For a top quality turntable, however, much higher compliance will take full advantage of the improved tone arm quality.
Our hand tuning assures exact adjustment to the ideal value for each specific model during cartridge production.
One of our most important design features is the use of two magnets. We'll tell you why in our next column.
Good listening,
Jon R. Kelly. President
Audio-Technica U.S. Inc.
1221 Commerce Dr., Stow, OH 44224
audio-technica. The World's Favorite Phono Cartridge
(Source: Audio magazine, Sept. 1984)
Also see: Audio-Technica AT160ML Cartridge (Sept. 1984)
audio-talk from audio-technica -- Number 4 in a Series (June 1984)
Audio-Technica AT15Sa cartridge (Feb. 1977)
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