VPI SDS owners-

Good points, Tom.

I believe those issues applies to every belt drive turntable with the exception of the direct drive....perhaps, which I have no experience with.

I had the same challenge trying to keep things in sync with my SDS. Although not a complete fix all, things are much, much more stable since I've had the SDS plugged into a PS Audio PPP.

Sounds like an isolation issue, that is over time your table is moving around a tad. Slight movements when you change the cart... just a thought. Btw I have the same table and my SDS is always spot on. I also use a 1000g clamp. Both the table and the SDS have their own stand. I can wrap the table hard with my hand while playing an album and you don't hear it...

Go figure.

One can also change the line voltage from the SDS to the motor and that often solves the speed instability issues. You can download the manual from the vpi website and there are instructions there on how to adjust the SDS.