Conventional thrust bearings in turntables create noise at the physical contact point due to supporting all the weight of the platter, whereas the Clearaudio bearing surfaces are relieved of this task. This may in part explain the very low claimed rumble figure of 92dB A (DIN IEC98, method A).
The Performance DC is built to a construction principle that Clearaudio calls ‘resonance optimised’. Its motor, platter bearing, and arm are all fixed to a solid, well-damped plinth made from a sandwich of two aluminium plates on a High Density Fibreboard compressed wood core. It feels very solid and heavy, which is no illusion, as the whole turntable weighs 11.5kg. To support and level the turntable, there are four adjustable feet.
Speed is electronically controlled, with 33 1/3, 45, and 78 RPM, all selectable by small crisply operating top mounted buttons on the left-hand side. There is no need to flip the belt up and down to change speeds, as on many turntables, making it very easy to use.
The Clarify tonearm fitted to the turntable is a beautifully jewel‑like piece of engineering, which is as good to look at as it is to operate. Like the platter, it uses magnetism, but this time to pull the arm-tube upwards, against gravity and the restraining tension of a single pivot wire. The arm bearing is therefore a unique kind of inverted‑wire suspension, or unipivot, with very low friction. The arm-tube itself is made with woven carbon fibre, which besides its high strength and low mass, provides a sharp high‑tech appearance.
Torsion is applied to the arm’s restraining pivot wire to achieve bias correction. This is set for a tracking weight of 2.4 grammes, which is typical of most modern MM and MC cartridges. If necessary, it may be altered by means of a rotary adjuster under the tonearm bearing, which applies torsion to the support wire. It’s a clever system, but to avoid mistakes, bias should only be altered with the aid of a test record, such as Clearaudio’s own.
Vertical tracking force is set by altering the position of the counterweight, as clearly described in the instruction manual. Because the magnetic bearing also applies a slight restraining force at the pivot, great care must be taken to adjust the tracking force with the stylus at the same height as the record playing surface (but with no record on the platter). The Clearaudio tracking force gauge is ideal for this job, because virtually replicates the thickness of an LP. Many other gauges are thicker and may give rise to the wrong force settings.