Why does the VPI motor thump

I had 2 VPI's and they both did that. I now have a Basis and it never does it. Simple answer: Bad design on the VPI's.

I don't necessarily think the tables are a bad design because they have a turn on / off thump. I usually judge a component by how it sounds when it's used as intended.

The thump is related to a capacitor required in the circuit. When used with a variac, SDS or other front end component to manage the voltage during start-up and playback, there isn't any problem.

But the design could be improved when not using some kind of voltage management device.

Bpoletti, with all due respect, I had an SDS on my Classic2 and Classic3 and there was still the same sound so I'm not sure what you're talking about.

Secondly, I didn't mean to imply that there are no good qualities to VPI tables but it seems reasonable to assume that if a person is spending thousands of dollars on a TT that they shouldn't have to mess around muting the pre every time they what to spin an lp, it's ridiculous. Considering virtually every other company seems to have figured out how to get the platter going without this obvious flaw, and it is a flaw no matter what VPI says, a company as wealthy and hyped as VPI could correct this, if they cared to.

@Moryoga ...check my posts above re my Classic TT upgrades which includes, in part, changing out the on/off bypass cap. Ok ... so the dumb stock bypass cap may not work 100% of the time for everyone. BFD.

The fix requires a screwdriver to open up the access port on the underside of the table. It's takes a few minutes to unscrew the 2 wire nuts that connect the bypass cap. Out with the old and in with the new. Screw the access plate back on. All done! And no soldiering.

If it take more than 15 minutes beginning to end ... the owner has all thumbs and no fingers.

IMO, the Classic is a fine sounding table. With a little practice, setting up the cartridge/uni-pivot arm is a snap, ... with a little help from the SoundSmith Intuit gizmo. I can do the set-up in less than 15 minutes in my sleep.

Just a quibble on my part. I think VPI has attracted an unfair number of swipes from a number of fellow A'gon members ... undeservedly in my view. The table is built like a tank and the arm works with most cartridges. It's easy to upgrade. I've changed out the entire uni-pivot assembly to the Classic 3 base and arm; the new bypass cap; plus, a 300rpm motor.

And the VPI folks (Harry, Mat, Mike, Jack and Jason) are always there to help if there's a problem. I always get through on the phone and turn-around with parts is same day or next day.

I just don't get it. I really don't. VPI is an All-American Classic (pun intended). And Stan (Stringreen) likes VPI tables too. :)

The only time I ever had a thump is when the motor cap went bad. I don't have the problem with a variac because there is no turn on / off of the motor, just the switch on the variac. I keep the variac set to 0volts for turn on / off.

You don't have any thump because you're using SDS.