VPI ADS controllo motore

External analog controller for the turntable motor, for 33 and 45 RPM

The ADS (Analog Drive System) is an external unit that powers and controls the turntable motor. Starting and stopping the platter, choosing 33 or 45 RPM and trimming each of the two speeds are all done from its front panel.

The circuit includes a pair of fully analog frequency generators, with low noise and distortion, and a Class-A/B amplifier with high current capability, coupled through a transformer to the output feeding the turntable. The control logic is analog too, to keep noise down. The front panel carries the Run/Stop button, a two-position button for selecting the speed and two separate adjustment knobs, one for 33 and one for 45 RPM: each has a centre detent calibrated at the factory and allows a continuous correction of +/- 3 Hz. Blue LEDs next to the knobs show the selected speed at a glance.

Key features

• Two analog frequency generators
• Class-A/B amplifier with high current and transformer output
• Run/Stop button and 33/45 RPM selector on the front
• Separate fine adjustment for the two speeds: +/- 3 Hz
• Blue LED speed indicators
• Power at the output: 15 W

Technical data

Mains input is 115 or 230 V AC, configured at the factory, at 50/60 Hz; the fuse is a 1 A slow-blow type (Slo-Blo). The output, likewise 115 or 230 V AC, delivers 120/240 V AC at start-up and 90/180 V AC when running. In the 60 Hz configuration the centre detent equals 60 Hz for 33 RPM and 81 Hz for 45 RPM; in the 50 Hz one it equals 50 Hz and 68 Hz.

Dimensions and weight

The ADS measures about 406 x 102 x 305 mm (width x height x depth) and weighs about 4.5 kg.