Drive System (ADS)

About the Drive System (ADS)

The VPI Analog Drive System (ADS) is a sophisticated analog speed controller designed for turntables using AC synchronous motors drawing less than 10 watts. It features two pure analog frequency generators that provide low distortion and noise, coupled with a high current Class-A/B amplifier transformer-coupled to the turntable output. The ADS includes analog control logic for low noise operation and offers 33/45 RPM analog speed adjustment controls with center detent positions factory calibrated for 60 Hz (33 RPM) and 81 Hz (45 RPM). The system uses analog logic controlled run/stop switching, initially outputting 120VAC RMS voltage on startup, then stepping down to 90VAC after an 8-second delay to quickly start heavy platters. The ADS is intended to remain powered on during listening sessions to keep the analog oscillators warmed up for lowest distortion. It significantly enhances turntable performance by delivering deeper bass, smoother midrange, sweeter highs, lower noise floor, deeper imaging, and an airier top end. This product is free of digitally based electronics and represents a major advancement over VPI's previous SDS (Synchronous Drive System).