Why does the VPI motor thump

John is right. Well known fact. I was a VPI dealer for many years and this goes all the way back to the HW-19 series.

I've personally owned well over 50 different VPI tables and most, but not all of them did this. I think it has a lot to do with the preamp and interconnect cables also. Many owners have stated that changing interconnects solved the problem.

It's not a VPI problem per se, but just the luck of the draw with associated equipment.

I've had a few good turntables. My Thorens never thumped. My Rega always thumped, and my Linn never thumps.

In my opinion, it's a flaw in turntable design. It's easy enough to implement a properly sized capacitor across the on/off switch so that this is never a problem. As a TT Manufacurer, VPI is aware of the thump potential and should design their tables to never thump.

Just another reason why to me VPI always see,s like a work in progress.

Before flipping the side of an LP I always turned volume down to 0, flip side, drop needle, turn volume up. I have never experienced any thumps with my Regas - P5, P7, and current P9.

Try plugging in the power cord on the VPI into one of those power strips with an on and off switch and turn the power on with the switch. If the thump goes away then you will know it is a bad switch on the VPI! I replaced the switch on mine with a heavy duty toggle and never had the problem again. It's worth a try.