Editor’s Note: This is the very first equipment report that was written by J. Gordon Holt for Stereophile, then called The Stereophile. The venerable JGH appended the following warning: The writer of this report was employed by Weathers Industries during the time when the product in question was undergoing development, so in view of this past association, and the doubt it may cast upon the writer’s impartiality, this report probably should not be published, even though the writer left Weathers Industries over a year ago and is not bound by any obligations thereto.
The product is not new, and has been written up in several other hi-fi publications, but perhaps because Weathers is only one of several advertising pickup manufacturers, the reports were not as forthright as they might have been. The pickup is one that deserves to be brought to the attention of audio perfectionists, so despite the taint of association between the reporter and the product, we are printing the report anyway.
When Paul Weathers finally released his professional stereo pickup system late in I960, the attendant publicity made it clear that this was not a stereo version of the well-known Weathers FM pickup, but it wasn’t very explicit about what this new pickup was. It was described as an “amplified bridge” system, using “ceramic capacitor” elements in an arrangement that was likened to a condenser microphone.
Well, the principle is not new, but the application is. The “ceramic capacitor” elements in this pickup are strain-sensitive; they emit voltage signals when physically stressed. But unlike the familiar ceramic pickup, this one does not bend its elements.
The low compliance and the high dynamic mass of the typical ceramic pickup are due to the rigid coupling between its stylus and its relatively stiff, massive elements.
This tight coupling is needed to bend the elements in accordance with the stylus movements, in order to get enough output from them to drive a high-level input. Weathers simply gave up high output for tracing ability.
Instead of trying to bend the ceramic capacitor elements, he evolved a pickup that barely “tickled” its elements. The only coupling between the cartridge’s stylus assembly and its transducing elements is a tiny rubber block at the base of the armature. This holds the stylus just rigidly enough to prevent it from folding up, and movements of the stylus are transmitted through this block to the elements as minute stresses. The elements are not bent perceptiblystress forces are all that are needed to generate the pickup’s low output and because of the very loose coupling, the stiffness and mass of the entire moving system should be barely more than those of the stylus and armature alone.
Like the FM cartridge, this one will fit only a Weathers tonearm, and must be used in conjunction with a small “black box” (gold, actually). This is a small AC-powered “polarizing supply,” containing two transistorized modules which provide equalization and some measure of preamplification for the pickup. The “amplified bridge” circuit referred to in Weathers’ data sheets is an arrangement whereby the very high-impedance outputs from the cartridge are matched to the inherently low-impedance transistor inputs, by inserting the signal into a feedback loop around the transistors. Both sides of the incoming signal circuits are above ground, and are carried through separate wires inside a tiny shielded cable from the tonearm to the supply.
Two sets of outputs on the supply provide a 1V signal with RIAA equalization, for feeding a Tuner or Aux input, and a 8mV signal at constant velocity, for feeding a magnetic phono input. There are no adjustments on the supply, and there’s nothing to get out of adjustment. The only adjustment in the whole system is the stylus force, and since this is controlled by a counterweight, it is likely to stay put.
The tonearm’s vertical pivots are displaced a small distance behind the axis of the horizontal pivot tube, so that while the vertical balance is thrown toward the cartridge (to provide tracking force), lateral balance is maintained, to reduce the arm’s susceptibility to jarring.
Recommended tracking force is between 0.75 and 1 gram. We found that it would indeed trace many records cleanly at 0.75 grams, and most records cleanly at 1 gram. But we also found that setting the force at a shade under 1.5 grams gave an added margin of tracing ability that cleaned up most of the discs that were only marginally clean at 1 gram. The extra force also reduced the tendency for the stylus to “hang up” on accumulations of the waxy substance that appears to be present in all vinyl record grooves. We have been using one of these pickups for over a year at 1.5 grams, and have yet to detect any audible wear of any of our discs (some of which have been played very frequently). And at that force, the stylus should last at least 5 years.
Performance claims like those for this pickup are difficult to verify, because they exceed the limits of most available test media. The separation figures, for instance, are better than those claimed by Westrex Corp. for their 1-A separation test record, few frequency test discs go out to 20,000 cycles, and of those that do, their response varies by much more than 1dB from one disc to another. Yet by using a band-pass filter to suppress rumble and surface noise, we did nonetheless manage to better Westrex’s own 25dB figure by over 5dB from 15kHz, and a visual estimate of crosstalk from a Pacific Transducer 60Hz15kHz sweep disc did nothing to verify or refute Weathers’ claims.
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Weathers Industries, Division of Teleprompter Corp.
Company no longer in existence (2019)
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