SDS

About the SDS

The VPI Synchronous Drive System (SDS) is a dedicated motor speed controller and power line conditioner designed to improve the performance of VPI turntables. It combines a turntable motor controller and line isolator into a single component, delivering cleaner power and precise speed control. The SDS uses advanced digital technology with quartz crystal accuracy to synthesize a clean AC signal, eliminating voltage spikes, low-level fluctuations, RFI, and frequency variations from the wall outlet. Rather than merely filtering power, the SDS converts input power to pure DC voltage and then digitally regenerates its own clean AC signal. The unit features front-panel controls for adjusting both output voltage and frequency, with large LED displays showing the actual frequency and voltage values. All voltage and frequency changes are applied gradually in a ramping fashion to prevent shock to the motor. During startup, the SDS increases output voltage to help the platter reach speed quickly, then ramps it down to reduce motor vibration and lower the system's noise floor. Users report improvements including deeper bass, smoother midrange, sweeter highs, lower noise floor, and deeper imaging.