How to identify the world's finest tonearm.
When one tonearm--among all those available--is described as "the world's finest," some controversy may be anticipated. Fine, we welcome that possibility. There is far too little discussion about tonearms--considering the critical difference they make in how records sound and how long they last.
Simply stated, the tonearm's function is to provide the correct cartridge-to-groove geometry and to allow the stylus to trace the groove contours freely, precisely, and with the lowest practical tracking force.
Dual's engineering approach to tonearm performance makes us feel confident of the outcome of any comparisons.
The basic geometry.
The shape of the Dual tonearm is a straight line from pivot area to tonearm head, the shortest distance between those two important points.
Curved tonearms may look sexier, but contribute extra mass, less rigidity and a tendency to lateral imbalance. That's hardly consistent with good engineering.
Every Dual tonearm is mounted in a true, four-point gimbal. The tonearm mass is centered, balanced and pivots precisely where the vertical and horizontal axes intersect.
Identical pairs of low-friction needle-point pivots and miniature ball bearings are used in both axes.
The precision and quality control standards applied to their manufacture and assembly are usually found only in aerospace and allied technologies.
Settings for your cartridge.
The vernier-adjustable counterbalance lets you set zero-balance with micrometer-like precision so that tracking force can then be set accurately. A tempered, flat-wound spring applies tracking force directly at the vertical pivot, and this force remains perpendicular to the record even if the turntable chassis is not level. Anti-skating is applied around the horizontal pivot, directly counter to the skating force, and it adjusts automatically to the varying skating force encountered by the tonearm as it moves across the record.
Another Dual refinement, not available on any other integrated tonearm, is the Vertical Tonearm Control. A vernier height adjustment over an 8mm range allows paralleling the tonearm to the record without cartridge spacers. Tonearm mass remains as low as possible, and mounting and changing cartridges are simplified.
Another Dual exclusive: tuned anti-resonance filters.
The counterbalance contains two specially tuned mechanical filters that absorb parasitic resonances originating in the tonearm/cartridge system and chassis. The result: flawless tracking stability maintained even in the presence of external shock and vibration whether caused by acoustic feedback, record warps or dancing feet.
About all Dual tonearms.
The tonearm shown and described here is part of our higher-priced turntables. But many of its features are found in our lowest-priced model: the four-point gimbal, the straight-line design, and the precise mechanisms for balance, tracking force and anti-skating adjustment.
In fact, we'd be willing to match the performance of our lowest-priced tonearm against anyone else's highest-priced tonearm. But one argument at a time is enough.
Now that you've been "armed" with the facts, we invite you to visit your audio dealer to examine the tonearms you find there-separate and built in-and decide for yourself which one is indeed the finest.
No one can argue with that suggestion.
Dual
---True four-point gimbal centers and pivots tonearm mass where vertical and horizontal axes intersect.
---The four needle-point pivots are tempered and honed to produce microscopically smooth surfaces---Each pivot is matched to a ball-bearing race only 0.157 inches in diameter
---Cueing descent speed and height are both adjustable, providing complete control of stylus setdown
---Vertical tonearm control sets and locks tonearm height at any point over an 8 mm range. Tonearm thus parallels record with any cartridge for precise vertical tracking without added mass of spacers.
---Unique counterbalance contains two mechanical anti-resonance filters which are specially tuned to absorb parasitic resonances originating in the tonearm cartridge system and chassis.
---Tracking force is applied with a tempered, flat-wound spiral spring, centered around the vertical pivot. Stylus force remains perpendicular to the record even if the turntable is not level.
--- Straight-line tubular shape provides maximum torsional rigidity and lowest effective mass.
United Audio, 120 So. Columbus Ave., Mt. Vernon, NY 10553
(High Fidelity, Nov. 1977)
Also see:
Dual turntables (ad, Jun. 1981)
Lenco Turntables (ad, Nov. 1977)
Technics by Panasonic -- SL series turntables (ad, Nov. 1977)