DESCRIPTION :

Obsidian is the latest result of Continuum Audio Labs’ decade-plus of research into turntable design. Following the launch of the Caliburn turntable in 2005, we have explored new areas of materials science, experimented with new mechanical ideas, developed new industrial designs, and recruited new experts to our team—all in the effort to bring the incomparable musicality of the Caliburn to a new generation of listeners, in an all-new design: Obsidian.

In ways, creating Obsidian was much like engineering an elite sports car. The knowledge our team gained in more than a decade of reference turntable design work could be considered its chassis. Obsidian’s innovative new DC motor, designed specifically for this turntable, is obviously analogous to the engine. As in auto design, metallurgy was critical—particularly in Obsidian’s extensive use of tungsten, an extremely high mass, inherently damped metal that our recent research shows is ideal for use in turntables. Of course, every great sports car deserves an innovative design, which in Obsidian takes the form of new elements such as a decoupled arm mount and a plinth-less base.

As do the world’s finest autos, Obsidian combines the work of many specialists into a perfectly coherent creation that delivers extraordinary performance. In fact, the creation of Obsidian demanded that we expand our “dream team” of top engineers and designers, bringing in new members with expertise in materials, physics and mechanics.

Obsidian’s visual aesthetics are as arresting as its sound. The plinth-less design places the tonearm and motor on separate, mechanically isolated mounts, so that any vibrations are thoroughly damped and/or channelled away from critical components. The simpler design eliminates many potential sources of resonance while creating an entirely new look that is revolutionary, yet driven by function.



Isolated Arm Board



Perhaps “arm board” is too pedestrian a term for the sophisticated structure that supports and Obsidian’s tonearm; “arm suspension” seems more appropriate.



Key to the function of the suspension is the sheer mass of the mount itself. Because the ratio of the mount’s mass to the motive force of the stylus is so large, the mount is no more affected by vibrations transmitted from the stylus through the tonearm than an elephant would be by a sparrow landing on its back. Because of its high mass, it is also effectively immune to ground- or airborne vibration.



The energy sink provided by the mount would be impressive in most turntables, but it still wasn’t enough for our dream team, who took the extra steps of double-isolating the mount using components made from tungsten, a metal that is 1.7 times as dense as lead and thus allowed our designers to achieve much greater mass in the same amount of space. Tungsten is used in the arm post and in the contact points for the arm suspension.



The entire arm mechanism is magnetically attached to the base of Obsidian, using tungsten contact points rather than fixed mechanical fasteners such as bolts or screws. In a sense, the mechanism floats on these tungsten contact points. Any energy flowing from the base to the tonearm, or from the tonearm to the base, must first make it through the tungsten suspension system. Which, for all intents and purposes, simply isn’t going to happen short of an earthquake.



The position of the mount is adjustable to accommodate practically any size of tonearm.

Massively Oversized Bearing



In the research we’ve conducted in our efforts to create the world’s finest turntables, we learned that the main bearing supporting the platter must not only be oversized—to spin smoothly while supporting the weight of the platter—it must also be “right-sized.” We seem to be among a small elite of turntable designers who recognize that the relationship of the size of the bearing to the size of the platter determines the resonance of the platter. Thus, we have sized the bearing so that all resonances are well below 10 Hz and thus have a negligible effect on Obsidian’s sound.



The bearing itself is a magnetically opposed design, but it does not float. This design reduces friction while maintaining a mechanical ground path that carries spurious vibrations away from the record and down into the base where they can be dissipated. It also keeps the platter vertically stable; maintaining mechanical contact does not permit the platter to wobble.



As in the arm suspension, the bearing benefits from the extraordinary density and natural damping properties of tungsten, which is used in the bearing ball and shaft. The tungsten components maximize transfer of torque from the motor to the platter while effectively eliminating bearing wear.

Innovative Motor Design



There are innumerable low-noise motor designs we could have chosen for Obsidian—but only one proved good enough to please our dream team of designers. In fact, this motor runs so smoothly its developers simply refer to it as “The Quiet One.”



The 35mm, 60-volt DC motor was designed and manufactured specifically for optimum performance with Obsidian’s platter mass and physical harmonic characteristics. It combines a set of specifications uncommon for low-noise applications, but that combine to deliver exceptionally smooth operation and the highest power currently available in a motor of its size. Its zero-cogging motor is controlled by a servo amplifier running at 53.6 kHz, far above the range of audibility.



The Quiet One uses stainless steel pre-loaded ball bearings. Why ball bearings, when sleeve bearings are typically preferred for low-noise applications? Because sleeve bearings do not have the load handling or durability of ball bearings—and through careful design, our dream team was able to ensure that any vibrations created by the bearings would be damped by other components in Obsidian’s structure.



The Quiet One uses graphite brushes. Why graphite, when precious metal brushes are typically preferred? Because precious metal brushes often do not have the current conducting capacity required to drive a heavy platter—and because our dream team created a special damping system, calibrated precisely for the motor’s speed range, that attenuates brush noise.

FEA-Modelled Nested Platter

One of the key things we learned during more than a decade of research into turntable design was that almost all turntable platters have significant and audible resonances. We realized that much of the character of certain turntables—descriptions such as “dark,” “bright,” “muddy” and “analytical”—stems from these resonances. But we don’t want our turntables to have any sonic character of their own.

This is why Obsidian uses a new, refined version of the nested platter concept we originated a decade ago. The shape and materials of the platter have been chosen through finite-element analysis (FEA) modelling to damp vibration emerging from the record and stylus as well as vibrations from the ground or the base. Through careful design, all resonances are shifted far outside the audio band, where they can have no effect on the music.

The entire assembly, built around a high-mass flywheel, helps keep the rotational speed of the platter steady and to further smooth the forces delivered through the belt.