Woofer pumping possibly due to tube amp when playing vinyl

I am moving this issue  to this forum because of what I discovered this weekend.

I’ve been trying to figure out why I have woofer pumping when I play vinyl, and for the last two weeks I’ve been messing with my vinyl rig trying to figure out what is causing the issue.  The woofer pumping seems to be more prevalent with the vertical up-and-down movements of the tonearm regardless of which turntable is being played. It appears it happens more at the outer edge of the record then the inner grooves.  I assume this is because record is more warped at the outer edges. The woofer pumping happens even in quite passages, so it’s not noise induced vibration affecting the turntable. 

 I have used two different turntables to try to figure this out, one is a pioneer PL 530, and the other is a VPI prime. both with different carts. Also, I have verified that all the carts being used on these turntables work well together with their respective arms.

However, it is not the turntable or cartridges. 

Things I can say for certain, it is not the turntable because I switched turntables with different cartridges to confirm this, and I still get the woofer pumping.  It is not a phono preamp because I’ve switched several phono preamp‘s, solid state and tube, and I still get the woofer pumping. It appears it is the tube amp that may be at cause. It’s the only component left of the chain. 
I have a Audio Research  Classic 60 amp. I got the amp used but it came with a new set of power tubes I don’t recall if I changed the four smaller driver tubes,  I also change the four large capacitors to new capacitors and biased the amp. 
The interesting thing is, with the TT’s I tried, it is the right channel that pumps more than the left channel, regardless of the variety of different cartridges tried, all aligned with AS Smartractor.

To be certain it was limited to vinyl playback, I plugged in a CD player and I do not get the woofer pumping at all. So I have a couple theories (1) the TT is just transferring subsonic frequencies from the records, ALL records I play do this.  Please remember, this is from the two different turntables being used, one a VPI prime belt driven, and the other a pioneer PL 510 Direct DrIve,  or (2) there’s some weird thing going on at the amp that I cannot explain. 
My question is, if there is something going on with the amp could it be a tube issue, or capacitor issue, or a biasing issue.  If so what is the most likely culprit.  Or I guess something else altogether. 
In the end I’m rather tired of chasing this ghost, and I would rather not use a subsonic filter if possible. If I do have to use a subsonic filter I want the most transparent one if such a thing exists. I’ve heard mixed results about the KAB unit. 
I have the KAB Rumble Filter and it is amazing. No sound degradation whatsoever. I have a/b back and forth probably close to 100 times in the 7 years I have owned it and once the levels have been carefully matched which I can do on my Mac C2500 preamp, there is zero difference. The 7 or 8 friends that have heard it concur with me.

In my system due to the location of the Turntable in conjunction with the speakers, It is one of 2 solutions. The other is to stop playing vinyl.
Lord. Of course its the turntable. Specifically, its the way the record is clamped to the platter. ALL records, if you just plop them down, are going to produce some degree of the very low frequency energy that you see as woofer pumping.

When I play records, any volume, there is plenty of bass and no woofer pumping. Without filters. Horrible idea! Look at my system. Please. Took the time to post the pics for a reason: so everyone can learn. Study, observe, and learn. Please.

Look close at the platter. Notice the black ring around the spindle? Looks like a washer. Its not. Its carbon fiber. Its hard to take a picture from an angle that shows every detail clearly so you have to really study it. Which you should do! Totally worth the time. See how thick the washer is? A record placed on this is held just very slightly higher than the surface of the platter.

If played like this, or if any record was played on this same table without the washer, just sitting on the platter, there would be all kinds of woofer pumping. Because at the scale of amplification we use even near invisible amounts of vertical motion at the record translate into a totally obvious pumping at the woofers. The fact you mention being able to see the tone arm move AT ALL tells me you’re not even close to doing it right.

So the next step after placing the record on the washer that holds it too high is to clamp it down. My record clamp is dished out inside, so as its clamped down it presses the record down onto the platter from the outside edge in. Fully clamped the record is absolutely flat on the platter. Its clamped so flat that when the clamp is released its like its been suctioned down onto the platter, which you can tell because when the clamp is released the records stay down for a second until air comes in and it pops up.

This is what you want. Its not your amp. Forget about that. Waste of time. Don’t move your table. Its embarrassing how far off track some of these ideas are. Look for a good clamping system. Clamp. Not weight. Clamp.
I moved both TT’s - all over the place.  Not change at all and that’s spiked through to the concrete floor. 


I can’t discount your thoughts about the clamp, but how would this affect the outer edge of the record where there is no clamp. 
I use a heavy record weight - which I know you say is no good - but it firmly holds the record onto the deer hide mat. 
I’ve also tried several matts to no avail. 
You’re definitely right about one thing, it’s not the amp, I just pulled out my old CJ MF2100, and I get it there too. So there goes that theory. 

"...it is not the turntable or cartridges..."
"...To be certain it was limited to vinyl playback..."

A bit of discrepancy in your conclusion but the cause is typically the ultra low frequency rumble from the turntable/cartridge combination. Check the Analog section or do a search. Lots of discussions and recommendations on this very subject.
I meant ALL my TT’s do it with ALL carts - exactly the same. What are the chances of duplicating the issue between to different TT’s and different carts. 
Also the carts compliance works with the arms, so there is no mismatch to be concerned here.

What,  I’m saying it’s VERY unlikely linked to an issue with the TT itself, but has to do with the subsonics coming off the record that both TT’s are picking up.

I can’t discount your thoughts about the clamp, but how would this affect the outer edge of the record where there is no clamp.
I use a heavy record weight - which I know you say is no good - but it firmly holds the record onto the deer hide mat.
I’ve also tried several matts to no avail.
You’re definitely right about one thing, it’s not the amp, I just pulled out my old CJ MF2100, and I get it there too. So there goes that theory.

I’m right about everything. All you have to do is read what I write.
how would this affect the outer edge of the record where there is no clamp.

My record clamp is dished out inside, so as its clamped down it presses the record down onto the platter from the outside edge in.

Got it? From the outside edge in.

I use a heavy record weight - which I know you say is no good - but it firmly holds the record onto the deer hide mat.
Where did I say deer hide mat?  
as its clamped down it presses the record down onto the platter
See? Platter. Not mat. Platter. Ditch the deer hide mat.

I’ve also tried several matts to no avail.

Yes, because that is part of the problem. Ditch ALL mats.


It is not the turntable.  I tried my VPI with 3 different clamps and none made any difference.  I still use the KAB with my Technics SL1200G and even though the noise was less it wouldn't go away until I used the KAB.  I used every type of isolation platform known to man on the 2 turntables I had, the VPI Prime and the Technics SL1200G, no difference.  I believe the stylus is picking up the sound from the speakers and re-amplifiing it.  The KAB filter is around $180-190.00 and it uses all audiophile approved high end parts inside.  Using it I am very much enjoying my vinyl collection again with no loss of sound quality.  To add one more thing, my Audible Illusions Modulus 3B had a subsonic/rumble filter and it did nothing, hence the KAB.
Well it’s not the music making the woofers pump since the pumping happens in the quiet passages as well. 
I never tried it without music so that is what I always thought, I was wrong on that one.                                                                                     
Wrong on all of it. You tried three different clamps. If none of them are designed like I said you could try a hundred more and it won’t prove a thing- other than that a lot of record clamps are of poor design. Which is why I made my own.

There are some good ones out there. I described exactly how they should look and work. Get one and use it. Problem solved.
It is not the turntable. I tried my VPI with 3 different clamps and none made any difference. I still use the KAB with my Technics SL1200G and even though the noise was less it wouldn't go away until I used the KAB ...
If it's not the turntable, or the match between cartridge and pickup arm, then it's the set-up. Rumble filters are really a Band-Aid. They work, but treat the symptom, not the root cause.
Well other than a clamp that works wonders, I’m not sure what is left for me to try. 

Here is a list of things most things I’ve done:

different cartsHead shell weightsAdjusted tracking force
different count wts
different antiskate
checked leads
different mats
different TT’s - in various locations
different phono pre
different pre Amps
checked different inputs on preamp
different amps
moving TT to concrete floor
Different cables
lifted motor off table so only belt spun platter

not sure what to check next. 
I would have thought that two different turntables without we skipped two different results but it doesn’t

Post removed 
Not sure if this is your issue but In 2010 I have a very significant woofer pumping issue with vinyl

That’s when I had a triplanar arm and ZYX Universe cartridge

We looked at isolation, the room, Speaker porting, suspension, etc etc like you are doing.

Like your situation it was worse on the outside portion of the record and exasperated on records with subtle warps

a lot of great insight from those posting here and our local guru here in New Orleans Richard Gray and Thom Mackris of Galibier converged on a solution. Major thanks to both.

Finally resolved what was wrong

the feather test - moving a feather lightly against the cartridge on the outer side parallel to the record should move the head shell and progress the record forward

if the cartridge doesn’t respond to the feather’s light touch and move inward then The tonearm bearing isn’t moving properly

The tonearm bearing wasn’t moving suficiently so the cantilever was moving up and down some instead of the cartridge moving in mass.
It would follow the groove forward but not have enough sensitivity to track things vertically correctly in harmony with the cartridge. That was what was causing all the pumping

It also isn’t kind to your deliccate cantilever suspension.

Most likely the bearing was restricted by dust in the equation.

I had the arm sent back and the bearing replaced by Triplanar and all was well

Since then I move up to a Durand tonearm.

I know you mentioned this was occurring with two turntables but each could be suffering from the same bearing issue to different degrees.

I wouldn’t rule the tonearm bearing out.
Particularly if you hadn’t played them in a while, there were similar dusting habits or if they are located in the same environment.

It is certainly worth a test.


Thanks for your input, while the pioneer is a traditional gimbal arm the VPI is pivot.  As you probably know there are no bearings per se, to be sure I checked the pivot point and the cup, both are free of debris or burring.  I also have the second pivot point for the VPI and I even disconnected it to be sure, but the pumping happened in both cases with and without the second pivot point to the same degree.
Yes the VPI pivot setup doesn’t involve a bearing - doh!

Watch the cartridges on the record

Is the cartridge moving up and down but most of the movement is in the cantilever? (The cantilever angle should be static)

If that is the case - the suspension on your cartridge has weakened and would result in woofer pumping.

You said you had swapped things in and out.
Is one Cartridge or turntable more prone to woofer pumping?

Both cartridges could easily be having these Suspension issues
I have a VPI Classic 1 with Lyra kleos and Zephyr when Kleos is being retipped and never had my woofers and subs pumping. Always had it set on concrete slabs, but I doubt that would make much difference, also use an outer ring but go without it at times and regardless of warp, I experience no woofer pumping.
Something is obviously wrong with your setup and I hope you figure it out.
From what is described here was very common long ago.  Noticed this in high school. Now to a lesser degree.  Warped Vinyl.  We had Sub Sonic or Rumble filters on our electronics to almost deal with it.  Back in the day we treated records like cd's.  Worst!  A $12.95 Astatic cartridge on a Magnavox phonograph could make my woofers dance with a warped record.  Now my delicate handling and care of my vinyl borderlines an illness.
When that stylus cantilever assemble designed to pickup microns of movement deflects .5mm up and down, your woofer is going to move.
Oyaide br-12 , one pound weight and good decoupling like iso-noe feet or better works fine for me .
Had that same problem with pumping woofers,but not anymore 
@millercarbon Can I ask where you got a carbon fiber outer ring clamp? I need one!

it has happened on all carts on both TT’s. 

Grado Sonata 3 (new)
Nagaoka MP200 (<200 hrs)
Nagaoka MP500 (<300 hrs)
Soundsmith Carmen II (<300 hrs)

they have all been aligned Using the AS Smartactor which takes error out unless you can’t read and follow basic direction. 
Also, both TT’s causre the pumping time be exactly the sameAnd at the same volume, even though one is DD the other belt driven, one light aluminum platter with stock rubber mat the other a 25 lbs aluminum platter with deer hide mat. I’ve sat them in the floor (concrete) to eliminate vibration as an issue, no change there either. 
In fact only thing the two TT’s have in common is the alignment. Could this be a cause?
It's obviously not warp vinyl. Something is seriously wrong with your setup. Good idea to start at the cart alignment and go up the chain from there.
I would recheck your cart alignment method. Likely you used the same on both TTs.  If more predominant on one channel, it may be trying to ride harder to one side. 
The other thing that comes to mind is the anti-skate setting if so equipped. 
I thought the same about antiskate.  I tried hi, low and off, nothing changed it. But I am using the same alignment and it is unique to the AS Smartactor.  It’s for better inner groove resolution. 
I will try a more standard alignment and see what happens. 
@millercarbon Can I ask where you got a carbon fiber outer ring clamp? I need one! 
Everyone does! Took mine to CES one year, compared with a bunch of em, its a great clamp. DJ Casser must have been impressed, he copied it, and so his stolen from me copy is as far as I know the only one on the market. Mine being DIY and a one-off. Its made from some BDR Shelf material that was left over after making the Miller Carbon turntable. https://systems.audiogon.com/systems/8367

DJ died about a dozen years ago, his heirs seem to be keeping the company alive but its not like it was. Far as I know BDR is only sold through Music Direct. I would call and ask if they can make you a record clamp. It will cost a lot. It will be worth it. Only clamp I know better than mine. Better made, better sound. He stole the design but give the man credit, he also perfected it. 

If they can't do that the next best would be order one of the Round Things with the threads going all the way through. Make sure your spindle is threaded to use this. Otherwise you need a collet type clamp. Which let me know, it can still be done its just more work. But a Round Thing, you can see them in my System pics, they are round and almost the right size. A little small but still better than every other clamp on the market. Then either dish it out like I did, or get an O-ring the right size to go around the perimeter so it pushes the record down from the outside area of the label. Then put a washer, or a small O-ring, near the spindle. That is the key. To push the record down from the center to the outside edge of the label, so when its clamped down the outer edge of the record contacts the platter first. 

This works just amazingly well. I really don't know what's wrong with the people here. They're talking about anti-skate, and every single crazy thing a guy could possibly imagine that can have nothing to do with it, while stubbornly refusing to see the one thing that will. Ignore the herd. Get a clamp. You will see.

Since a number of things have been tried on the 'table, I am starting to suspect the phono section might be playing a role. What kind is it?

The fact that its a problem with the turntable and not the CD player rules out the line stage and amplifier entirely.

So it is either the preamp or the turntable, and
the chances of duplicating the issue between to different TT’s and different carts.
-is actually a lot higher than you apparently suspect! BTW woofer pumping has nothing at all to do with whether circuitry is tube or solid state.

I agree that ditching the deer hide platter pad is a good idea. A proper platter pad will damp ringing in the platter and also vibration in the LP itself; deer hide will help with neither. I would think that the deer hide will be really tricky to maintain a uniform thickness- that might actually be the problem right there.

Millercarbon, your system must cost a fortune.  I can't believe you are satisfied with listening to music in that kind of environment.  I like to incorporate listening into a beautiful room such as a family room so when I have company they can enjoy the music as well.  However, I am sure your system must sound incredible.  I noticed you have speaker wire stands.  What do they do and can you really hear the difference.  Looking at your system, there must be a lot of wealthy people in this group.  However, it is nice to learn from those who have invested a lot of money into their systems to achieve near perfect sound.  They must have near perfect ears to hear the difference or they have dialed in the sound that best maximizes their hearing.  What might sound perfect to one person must not necessarily sound good to another.  Nothing wrong with dialing in the sound best suited for your hearing because it is who is listening and who is investing this kind of money that matters.  I often think about this realtor who sends me listings of homes being sold in my area over the past 3 years.  He has sent me over 1,000 listings and I have yet to see one room with a pair of speakers standing.  I cannot believe people have a $5,000 piece of furniture with a wide screen TV and are willing to listen to the TV speakers.  I think 70% of the experience when watching to a movie is sound.  I also can't believe they don't like music.  Nothing nice than to have people over for cocktails and listen to music in the background.  I think most people are allergic to music are simply think music is noise.
I use a TTW audio outer ring extreme V2, made in Canada. Extremely efficient and much less expensive than the VPI outer ring. That being said, once again, I don't believe that's your problem since I have never experienced the woofer pumping you describe before I got my outer ring even so I played some seriously warped vinyl.
I had a woofer pumping issue when playing vinyl a couple of years ago. The first thing I did was make sure the TT was as level as I could get it which helped a little bit. The other thing I did was place the TT on some anti-vibration pads like these https://www.amazon.com/PneumaticPlus-Anti-Vibration-Rubber-isolation/dp/B00HZS0CH6/ref=sxts_sxwds-bi...and the issue for me at least was eliminated. 
Thanks for all the input, here are some of the responses to some of the questions:

The platter is dead level I’ve checked it out digitally and with a old fashion bubble level
I’m pretty sure it’s not the phono preamp, I tried a Dynavector mkiii phono pre and an an Audio Research PH3se phono pre, it does it on both.
I have a Parasound JC3+ in another system, so I might try hooking that up as well to see if it happens.


i have those pads too, and tried them. No change. 

After all this (I'm exhausted from reading what you've already done/tried LL;-)...

Why not hook up the Halo 21 from your other system to rule out the ARC 60 being the culprit?

Highly unlikely, but then it's a 20+ year old tube amp with work already done to it, and then you will know.

I had no idea there was so much to dragging a rock across some plastic. Good luck!
Post removed 
This issue does not have anything to do with a tube amplifier.

You need a better turntable and a subsonic/rumble filter. I am surprised you see it on a VPI however since it is usually a better turntable.

The rumble usually (but not necessarily only) comes from the main bearing of the turntable and is at very low frequencies (8 - 20 Hz). You can sometimes hear it and more often actually see it (as you have in your woofer).

It is the noise generated from the bearing shaft & the sleeve grinding against each other. No matter how excellent and/or mirror polished the main bearing may be, at the end of the day, they are still two separate pieces of material grinding against each other. You should see it under an electron microscope and you will understand :-)

Typically good turntables have a rumble figure of less than about -75 db or so (quiet). Excellent ones reach down to -82db ish (very quiet). You can reduce it but never eliminate it completely. It becomes pretty audible and a nuisance at around -70db or higher (give or take a few dbs, not an exact science).

Limitations of analog playback :-)

@ last_lemming, Take a look at a walker audio crystal reference record clamp. It is a great clamp. :-)
@ last_lemming, have you measured the vibration at the turntable platter directly?  I have an app on my phone that will measure vibration on a surface in the X-, Y-, and Z-axes.  It might be instructive to get some sense of the magnitude of any disturbances that might be causing the woofer pumping.  It can also be useful to determine if any vibrations might be cyclical in nature.  This could be the case if an appliance (e.g., a refrigerator, air conditioner, heating plant) is the source of the problem.  Have you measured any vibration on the walls or the floor of the room, either with your hand or using some sort of instrument?  Seems like you've exhausted pretty much all of the more system-specific possibilities so maybe it's worth looking for another environmental cause.
I agree with larrys. One time my turntable's lid was tilted and  vibrating which caused such woofer pumping. (I learned my lesson). It may be a mechanical vibration in the room around 1-20 Hz range and stylus is picking it up. 

I have considered this but the nearest appliance is a gas range opposite Side of the wall. 
If there is a phone app I’ll certainly give it a try. Got nothing to lose. 
One thing I don’t understand is the speakers go down to 32hz, but sub-Sonics can be far lower, so how do the speakers reproduce below there operable range with such amplitude as to move the woofer in and out 1/4” or more, when my strongest bass note I can get when turned up only moves the woofer 1/16”. 
The operable range of the speaker is usually described as the range in which it will reproduce sound, which is why a +/- dB specification is the norm.  That doesn't necessarily describe the range of frequencies that the speaker can physically respond to - you can put a 1Hz signal into a speaker and the cone might move but you wouldn't hear it.  

In terms of the proximity of an appliance or source of the subsonic signal, that can travel a long way, especially in a solid substrate.  Earthquakes, trains and sonar are good examples.

Given all of the tests you've performed so far, swapping channels and even equipment, it's hard come up with any source of the movement directly related to the electronics (I'm including the cartridge here).  Does your preamp have a mono switch/setting?  Switching to mono should cancel the vertical component of the cartridge output  You may have tried that and I missed it.  

Finally, is there any chance that the speakers themselves are contributing to the problem, perhaps through differences in the crossovers or the drivers themselves?  Very unlikely, but something that might be relatively easy to check. Have you tried swapping the speakers left/right? Physically isolating or moving the speakers?  If the pumping is altered by any of these changes it might point to a cause.  
I am assuming you have lifted the subwoofer off the floor to see if it stops.
Many amps roll off below 20 Hz so you won't see woofers pumping. Your system is doing exactly what it is supposed to do. Moving the turntable won't change a thing. Anybody who uses subwoofers aggressively and plays vinyl will need a subsonic filter. The problem with many rumble filters is that they start rolling off between 30 and 40 Hz so your audible bass is affected. 
Woofer pumping is a big problem. It wastes power and forces your drivers into non linear operation increasing distortion.
The best subsonic filters are digital. My filter starts at 18 Hz and is 60 dB down by 1 Hz. It is totally transparent. If you switch it in and out playing a digital source you can not tell the difference. If you switch it out playing vinyl?? I have 4 12" subwoofers each one driven by 2000 class AB watts, damping factor 500. With some records the drivers will bang against their bump stops!
This is just one advantage in having a digital front end aside from bass management, room control and equalizer functions. 
If you have subwoofers, play vinyl, and have amps that go down to DC you positively, absolutely need a proper subsonic filter. 
Thanks for the responses

to answer some questions:

no sub is in use

my preamp does have mono but didn’t affect the pumping

I will try different speakers to see how that goes.