Why does the VPI motor thump

Why is it when I turn off my VPI motor I hear a thump through the loudspeakers? The only direct connection to the stereo is the belt.
There is a small capacitor in the motor assembly. Either yours has burned out or isn't there or isn't large enough.

Contact Mat at VPI and he'll send you the one you need.

I have the same issue on my Classic II. Matt was somewhat offended when I asked him how to fix the problem. He made it abundantly clear that it was NOT a problem with the turntable but rather my preamp was picking up the collapsing magnetic field of TT motor when turning it off.

He said the two solutions are either install a larger cap ( I don't recall the value) or use the mute switch on the pre, which is what he does. That seems to be the easiest solution so that is what I do too.
Well I just installed a new 300 rpm motor and it thumps more than the 600 rpm. It did come with a new yellow capacitor and I did install that. The only carryover part was some type of roundish electric piece with two wire leads. I installed it in the same place.

But all that aside, why is there a sound made through my speakers at all?
That thump is why I mute my preamp before turning the motor off. I change LP side, clean LP and stylus, start the motor, wait for the stylus to drop into the groove then I un-mute. No thump through the speakers with the preamp muted. Mofi's explanation about the capacitor issue is a long running problem with VPI motors.
04-16-14: Stringreen
..then why does my VPI turn off silently??

Luck? Or do you use the mute switch too?
No one said that every single motor VPI ever made thumps, but obviously there are enough of them out there on the market that do thump that threads like this are very common. Search the archives here and at AA, you'll see that this is a common problem.
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.
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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.
Is there a material that can shield from the magnetic field?
I would buy another capacitor from radio shack if I knew what type and size to get. Does anyone have any info on that?
I purchased a VPI 'Scout' when they first came out, and thought that I had the turntable for the rest of my life. The motor was just plain noisy, and there were other issues, which I am not getting into here, but I got rid of my VPI very quickly.

Very disappointing!
Try a .047uF/630V. LL shoot me a PM and Ill put one in the mail to you, its a 25c part.

BTW ANY power switch on ANY component will make a thump in the system if not by passed with a capacitor, its not only a VPI issue.

Best of luck

My TT motor on/off switch has no capacitor and it never thumps.

Of course it's battery powered and not connected to the electrical system.

In my earlier post I incorrectly said I spoke with Matt, it was in fact Mike. Here is his response regarding the cap value he recommends.

"We use a .001 microfarad capacitor across the on-off switch because it usually works with most components to eliminate the pop, you can change that to a .01 microfarad cap and that usually helps or eliminates it with some of the other components available."
This is the reply I received from Mike at VPI in 2010 after I had this problem with my Classic 1. It completely fixed my thump.

VPI Customer Service

The pop is system dependent and since we have no idea what a customer has we install the cap that works 80% of the time. You need to change the on-off bypass cap to a .01 microfarad 400V non polarized cap. We usually install a .001.

...just thinking....maybe because my system is totally balanced may have something to do with the silence of switching off my VPI
I mute my phono pre before turning on the TT, so I have no idea if my TT would "thump" if my phono pre was not muted.

More importantly, ... I have no intention of "testing" my set up to see what would happen if I didn't mute the phono pre. Why would I want to take a chance of damaging a speaker or downstream component because of a TT thump or transient or accidental tone arm drop??

So what if the TT thumps when switched on. What's the issue?? Who cares? Why is this even a question?
My Classic had no problem with ASR integrated amp. When I swithced to Lamm, I had the thump problem. My local VPI dealer
just came over and change the capacitor for me. If I remember properly, it was just a capacitor with a little clip on thing, took all of 10 second to change it but it has to be done from the underside of the turntable. No more problem for a long time now.
But Zavato ... why aren't folks using the mute button to protect their systems from such transients??
It's not a matter of not wanting to use the mute, sometimes you just forget that little step and hit the off button on the motor - then THUMP!!!
It's a thoroughly avoidable problem- that's why it's annoying to encounter in a turntable that frankly is not cheap. There is absolutely no sonic trade off using the larger cap in the first place. As mentioned above it's a 25 cent part.

Yes, you can use the mute button but- 1- we sometimes forget; 2- it's an unnecessary extra step that's really a work around for an inadequately engineered product.

I like VPI designs (and I have a 16.5) but ever since first auditioning an HW-19 perhaps 20-25 years ago, I've been skeptical of VPI as well and nothing over the years has changed that impression.
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I asked my local VPI dealer once why VPI does not install the bigger cap right from the beginning so we can avoid this problem. I was told that the big cap does not totally prevent the problem either as some systems will have the same problem with bigger cap rather than the smaller cap ( I don't know if this is really true but it is what I was told anyhow) so it seems like there are 2 versions of the cap and VPI installed the one that should work with the majority of the system (80% per VPI)as standard. If this is the case, I don't see that it is any different than certain preamp that needs to be turned on before power amp otherwise you can get a big thump as well if you turn it on after turning on power amp and I would not think that that preamp is crap either!
Ok ... I pulled my VPI Classic out of the trash and against my better judgment turned on the TT with the rig set at full volume -- no mute -- to see if there was a thump on turn-on. No thump. Oh well ... guess I'll keep this pile of junk for a little while longer. I know it plays great music, but I can let thump-free great performance get in the way of the "unfav" comments above. :)
Correction: double checked thump on turn ON. No thump. However, slight pop on turn off, but not a thump.

But really. Who cares? The TT runs dead quiet as best I can tell and my Lyra Kleos tracks beautifully on the Classic 3 arm. Sorry guys, I think this is a lot of nitpicking.
VPI Tweak News: Just installed a 300 rpm motor and new larger on/off bypass cap. To be clear, the 300 rpm motor comes with a slightly larger sized cap than the 600 rpm motor. But I had to ask VPI to send me the larger on/off bypass cap. Absolutely no thumps. The motor is dead quiet. And the TT works just fine.

FYI for other DIY'ers: My version of the earlier Classic plinth has a circular metal disc which is hot glued into the plinth structure directly underneath the 600 rpm motor. Dunno if its the depth of the 300 rpm motor, or just the way the early version Classic plinths were made ... but the metal disc in my plinth had to be pried out or the new motor would not lay flush with the top of the plinth.

Removal required a flat-head screw driver. I just jiggled the metal disc out with the flat-head screw driver. VPI has a round rubber sticky that goes on the bottom of the 300 rpm motor. As best I can tell, the metal disc serves no purpose and the rubber sticky works just fine. Bottom line: no motor vibration or noise. Everything seems to work well.

Btw, this is a good time to clean and relube the main platter bearing with white lithium grease. Not sure I needed to put a tiny drop of oil into the new motor ... but did. Just a very tiny drop.

So ... for those who have a Classic TT with the 600 rpm motor looking to switch to the 300 rpm version, be sure to ask VPI to send along the larger on/off bypass cap and the rubber sticky thingy in the kit.

At this point, the only other tweak to turn my TT into the Classic 3 is the plinth. All other components are Classic 3.

Per Mat Weisfeld, there's not much more I can do to tweak the TT, except maybe for better feet, like Bear Paws. I have a DIY idea which may obviate the need for new feet.

Been thinking about building a sand box sub-base. I would cover the sand with a piece of thin rubber to prevent sand from getting into the TT. On top of the rubber covered sand sub-base goes my 35 pound 2" thick maple slab TT base, which I already own. On top of the maple slab sub-base goes the TT.

P.S. When my wife first saw the maple slab, she didn't get angry because I spent more money on my rig. Instead, she tried to take the slab for the kitchen Fortunately, it weighs 35 pounds and she gave up. :)

P.S.S. -- You may ask, does the new motor effect any improvement. Not sure. If there's an improvement, it's subtle. The main reason for doing it was boredom. Also, I'm sure it will make Stan (Stringreen) happy. :) LOL
Post Script to Stan (Stringreen): Stan, what are your thoughts if I paint my plinth with a shiny garnet black lacquer? It still won't be a Classic 3, but it may look like one. LOL

If a variac or SDS is used to manage the motor, there is no start up thump or pop.

I had the pop with both a TNT and an Aries motor. Currently using a variac on the Aries. Totally quiet start up and shut down. I turn on the variac when I turn on the preamp with the voltage set to 0v. I increase to 110 for start-up and and record brushing, then dial back to 60v for playback. When finished with a side, the voltage is doaled down to zero.

I like the very quiet background it provides compared to plugging the motor directly into the wall. Not sure I actually need something like a SDS because the speed seems OK.
Perhaps my system being totally balanced (all XLR connections) including turntable and everything else has something to do with it???
String, you're using a SDS. That isolates the motor. No thump. So does a variac and performs the most important functions of a SDS (isolation and voltage reduction) though manually.
@Stan (Stringreen) -- does your Classic 3 motor get very warm to the touch? Been playing my TT. It occurs to me that the new 300 rpm motor gets pretty warm to the touch, actually quite warm. The old 600 rpm motor, while warm, did not get as warm as the 300 rpm motor.

I'm trying not to use the word "hot", but the motor almost feels hot after use.

Any thoughts or comments??

Bifwynne.....Actually, I have a modified Superscoutmaster rim drive.....doesn't get warm at all. Never heard of an overheating complaint from others I know who own a Classic 3
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.
I bought my Classic 2 used from a highly reputable store and then bought my Classic 3 at the VPI factory where Harry personally put the box in my hands. Both of these tables made the exact same noise when hitting the power switch. I have no personal problem with Harry as a person, he seems like a very nice guy but this particular issue is a problem. Customers shouldn't need to do a modification or upgrade to have a product work without problems. I don't think that this qualifies as "VPI bashing", I think its calling a spade a spade.
Why not blame the preamp? Why not blame the AC cords or the ICs to the phono stage? If the stock cap works for 80% of the VPI tables, I would look long and hard at other components' placement and emi/rf sensitivity as well. Some components do not play well in proximity to some others. I have to be careful with placement of my phono stage and its separate PS to avoid problems like low-level AM radio and various hums reproduced through the speakers. Careful placement away from my amps and especially, the VPI SDS gets me superb sound while sloppy placement gets me mysteries to solve. Some placements I tried while getting to the current one also caused the turn-on thumping, but only when using the switch on the 2-motor/flywheel body rather than the SDS. This does not happen in my current configuration using all the same components and cables.

Solving the problem at the TT end might keep you from finding a solution that is also causing you not-yet-detected problems elsewhere in your system.