You may be measuring speed inconsistency (which comes in many different varieties), but I don;t think you are measuring flutter.
A relatively easy way to HEAR ordinary flutter is to play a recording of a solo acoustic piano and listen for the notes as they trail off and decay.
The VPI SDS and ADS, as well as similar units from other manufacturers, improve speed consistency by cleaning up the power going to the TT motor and by lowering the voltage after start-up. They do work. What also works is the addition of physical flywheels, and the replacement of bearing (and motor) lubricant when required.
A relatively easy way to HEAR ordinary flutter is to play a recording of a solo acoustic piano and listen for the notes as they trail off and decay.
The VPI SDS and ADS, as well as similar units from other manufacturers, improve speed consistency by cleaning up the power going to the TT motor and by lowering the voltage after start-up. They do work. What also works is the addition of physical flywheels, and the replacement of bearing (and motor) lubricant when required.