VPI Industries VPI - Synchronous Drive System (SDS) - NOT A TURNTABLE

WHAT IT DOES? The SDS provides the line voltage that all domestic turntable equipment requires. The difference between the SDS's conditioned output and that provided by your local electric company is that the SDS gives you a highly stable, pure sine wave instead of the often "dirty," and unstable line frequency you get from your wall outlet. While there are other devices that filter spikes, surges, and R.F. noise, only the SDS provides a pure, double filtered, stable line frequency and voltage. The SDS is like a “Black Hole” for noise. WHAT CAN YOU EXPECT? Any fine turntable will deliver even better performance. Such improved performance results from the purity of the Alternating Current supplied by the SDS. With the motor providing more even rotation, distortion is lowered throughout the audio range, bass is tighter and better defined, attacks are cleaner, and the mids and highs more detailed. You may also notice a greater openness and depth than before. The extent of the improvement depends upon how sensitive the turntable plugged into the SDS is to "dirty" line voltage. All turntables will improve in sound quality. FINE SPEED CONTROL Because the SDS lets you vary the line frequency, it allows fine speed control for many turntables, which have, up to now, lacked this refinement. The turntable must use an AC Synchronous motor without any intervening electronics of its own for this fine speed control. By varying the frequency of the line voltage supplied by the SDS, considerable speed variation is possible. Using a strobe disk, it is now possible to set the turntable for exact speed. Varying the speed of the turntable will also change the pitch of the music. This allows for making corrections in the pitch of many historical recordings, which were not transferred, to LP at the proper speed.