Acoustic Research XA

This is the original AR turntable. It had a two-piece aluminum platter  which was driven by a small synchronous motor. Early versions had two  motors to add the extra torque needed to start the heavy platter. A  spring-suspended subchassis supported the platter and tonearm. The  tonearm had manual adjustments for weight, no real anti-skating, and  damped cueing which prevented accidentally dropping needle to the record  surface. The tonearm was S-shaped with a single pivot point. The table  was extremely quiet and immune to rumble.   Early models used solid  walnut sides, then they became walnut veneer, and finally walnut looking  vinyl veneer.

Key Features

1. Sub-platform suspension: The platter and tonearm were mounted to a sub-platform suspended below the top plate by damped springs, effectively isolating them from footfall vibrations and acoustic feedback.

2. Lightweight, belt-driven motor: A low-power, synchronous motor drove the platter via a precision-ground rubber belt, minimizing rumble and ensuring accurate speed.

3. Lightweight platter: The platter was made of thin, non-resonant aluminum, reducing the flywheel effect and minimizing speed variations (wow and flutter).

4. Simple, durable design: The turntable’s Spartan design featured a two-piece aluminum platter, a T-bar sub-chassis, and a minimalistic tonearm.