** THIS ITEM IS A DEMO - Full Manufacturer's Warranty **
VPI SDS Synchronous Drive System Speed Control Device
Dead-On Accurate Speed for Perfect Timing and the Lowest Possible Wow and Flutter
VPI's Synchronous Drive System (SDS) combines a turntable
motor speed controller and an AC line isolator into a convenient and
compact package. The SDS breaks new ground in clean accurate power
delivery using advanced digital technology and quartz crystal accuracy.
Simply plug your VPI turntable into the SDS and hear
the improvement a proper motor drive will create; solid and deeper bass,
smoother midrange, sweeter highs, lower noise floor and deeper imaging.
The SDS allows for proper calibration of platter speed, ensuring that not only does your VPI table spin at a constant speed, after calibration it will also spin at the correct speed! The SDS allows for individual speed corrections for LPs and 45s, in increments as small as 0.01Hz. The ability of the SDS to make such fine corrections, allows the user to truly "dial-in" the performance of his VPI table, regardless of model.
The SDS allows for the adjustment of both the voltage and
frequency fed to the turntable motor. Adjustments are easily made from
the front panel using intuitive, soft-touch controls. The selected
output voltage and frequency are shown using large, easy to read LED
displays. The SDS slowly ramps thevoltage and frequency up or down to
the selected value in order to prevent premature motor wear due to
abrupt changes. During motor startup, the SDS increases its
output voltage in order to bring the platter up to speed quickly. Once
the desired platter speed has been reached, the SDS ramps the output voltage down in order to reduce motor vibration and, therefore, the system's noise floor.
The circuit used in the SDS provides an incredibly accurate
line frequency of great stability. Additionally, the electronic
circuitry effectively isolates the output voltage from the input
voltage, doing away with voltage spikes, low level fluctuations, RFI,
and frequency variations.
Instead of merely filtering the power line, the SDS first
converts it to pure DC voltage and then digitally regenerates its own
clean AC signal. This approach is superior to that used in many of the
other power line conditioners on the market.
The SDS is designed to work with the AC synchronous motors in VPI turntables.
The speed of a synchronous motor is determined by the frequency it is
fed. Logically, a device whose speed is based on the AC line frequency
will function better when a stable consistent frequency is delivered.
Constant motor speed translates into a quieter, more faithful musical
Many historical recordings were not transferred onto modern records at the proper speed. Using the SDS
you can now correct the musical pitch of these recordings by varying
the speed of your turntable. In addition, collectors who have VPI
that run at 78 RPM will be able to accurately adjust them to compensate
for the wide variation in recording speed used in the 78 RPM era.