Custom Turntable

Here is my custom turntable, based on the old AR design. This design, with its separate, dampened sub-chassis, needs little introduction and has proven itself over the years.

It would be incorrect to call my turntable a "mod" of the original AR, more like an adaptation, since all the parts except the three suspension springs and the belt were newly manufactured for this unit.

The inner and outer platers are machined from solid aluminum and coated with Soundcoat, a sound- deadening product. The bearing is machined from solid Teflon, with a high-speed steel pivot point at the bottom. A high-speed steel insert in the end of the stainless steel record spindle bears on the cone-shaped HSS pivot point, a very low-friction arrangement. In the eight years that I have been running this 'table, there has been scarcely any wear at the bearing point. Moreover, the bearing is so ultra-precise and low-friction that when you give the inner platter a push with your hand, it will go on spinning for several minutes!

The inner platter is driven via an AR belt by a standard, off-the-shelf Hurst 300 RPM synchronous motor. The motor is fed a pure 120V 60 Hz signal supplied by a variable speed electronic power supply (not shown) built in 1996 from an article in Audio Amateur. The measured distortion from this source was under 0.5%, and needless to say, very stable.

The tonearm is an SME 3009 II, with a Denon DL-301 Mk II fed into (2) Lundahl LL9206 step-up transformers feeding a Curcio Sarah phono preamp (not shown). The cartridge/arm combination works well.

View with the outer platter removed. The inner-outer platter configuration is a very practical one, as it greatly eliminates the potential for vibration and resonance.

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