Woofer pumping possibly due to tube amp when playing vinyl

Welcome to the (very 20th century) world of imperfect records and turntables.  Noise and distortion is par for the course.  People spend fortunes on turntables and good pressings to avoid that.   That’s just one reason why digital streaming rules in the 21th century.  But gosh darn those imperfect ol records are just too darn much fun to dabble with to ever give them up totally once you have them.  The joys of analog home  hifi!

When my woofer was crazy pumping (moved heavy curtains behind my speakers) it was due to my Pass Labs phono stage. Changed back to my tubed Manly phono stage it it stopped about 80%. I then changed to a T+A phono stage (inserted inside my T+A HV integrated and it solved the problem 100%. Can play extremely loud, no thumping. The T+A phono stage also outperforms the Pass and the Manly. 

@last_lemming did you ever figure out what was causing the woofer pumping? I'm having a similar issue that is not responding to the usual solutions. 

Put your dustcover on the TT when playing a record. Place a heavy blanket over the the entire TT. See what happens

This only happens when the vinyl is playing. 
It does the same thing on 3 different TT’s with 3 different carts, all carts are known to work with the TT’s, so a mismatch is highly highly unlikely at this point. 

Does it do it without the arm on the LP surface- if you just touch the sylus, can you set it off into pumping?
If no, then the problem is simply that the turntable suspension, in tandem with a mismatch between the arm and cartridge, is the culprit.

yes it still does.  Not only that I turned off every circuit breaker in the house other than the one it was plugged into in another room and it still did it

If you run a power cord from a different room (hopefully one not on the same circuit breaker) for the preamp, does it still do it?

Yes it does. 

Thanks! Is this affected by the volume control?

If I had to guess, I’d say 2-3 oscillations a second. Though the amount it moves in and out each time varies. 

^^ +1 My phono section has bandwidth to 2Hz and no worries about woofer pumping- my system is flat to 20Hz and the woofers are calm unless there are bass notes.


The KAB knocks out low frequencies and part of the reason it sounds different is not only more amplifier power but also phase shift. IMO/IME its better to get a handle on this rather than place a bandaid on the problem. The result will be better sound.


@last_lemming If you had to describe the woofer pumping, how fast was it?

gibsonian

Rumble filter is simple and easy, no big deal. Get one and move on. They’re in most all phono pre’s, for a reason.

A rumble filter is a Band-Aid. While they are common on older receivers and lower-end equipment, you’ll find they are much less likely to be included on better gear, where the manufacturers expect the user to be using a properly setup quality turntable. For example, the phono stage I use is spec’d to be within ± .2dB at 10hZ and down just 2dB at .3hZ. My speakers are relatively flat in-room to below 25hZ. No woofer flapping, no rumble filter needed.

Well. I literally tried everything there is to try. Nothing worked . . .

. . . except the KAB unit. It does affect the sound, but I need more time to figure out exactly what has changed. 
But the GD woofer pumping is DONE!

Rumble filter is simple and easy, no big deal.   Get one and move on.    They're in most all phono pre's, for a reason.

I did. No change. 

Have you tried the periphery ring yet?

You might have a power problem. I saw a situation once where a tube power amplifier drew enough power that when the preamp was on the phono, it was possible for the amp to drain the AC line so far that the preamp started to shut down. That caused it to put out a pulse which caused the amp to shut down a bit- then the line voltage recovered, the preamp made another pulse as a result and the cycle continued- woofers pumping. You could stop it by turning the volume down.


It would only do it with the tube amp that had greater draw and only when on the phono input (which has more gain and so is more sensitive to issues with voltage regulation).

If all the gear works in another room (and hooked up to each other the same way) then I would look into this. It might be as simple as a bad connection on the back of an AC outlet or in the breaker box. A digital voltage meter set on the AC voltage scale and plugged into an outlet on the same line might reveal this problem unless its associated with a particular outlet.

There is probably nothing you can suggest that I haven’t already tried on 3 different TT’s and ended up with the same result. 

not the front end, I’ve eliminated those as variables. Since they are all fine in one room but not the other. 

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.

Tail wagging the dog. Listen to @ millercarbon and others. Work on the front end.

Thom @ Galibier Design

Hirnd2,

I don’t have a EQ to do what you say. 

Yes I did. No change. 
Also I got the perimeter ring in. Nice piece, keeps the record very flat, but didn’t really change anything. 
I guess it’s a KAB unit unfortunately. 

There is but it’s about 8 feet away.
Oddly enough it’s only 2 feet away from the system that doesn’t pump.

Did you try shutting it off anyway? The noise could be getting in through a power cord.

Cut the subsonic energy, Did you try that? Hook up and equalizer and cut 20 hz 15 db Did that help, I bet it did.

There is but it’s about 8 feet away. 
Oddly enough it’s only 2 feet away from the system that doesn’t pump. 

Again, on quiet passages. It’s not a physical manifestation, it’s electrical.

@last_lemming  Is there any sort of digital, bluetooth or other device that can make RFI near the phono preamp or phono? I've seen cell phones induce woofer pumping as well as defective digital gear.

mijostyn

Cleeds, the problem is your room is not flat down to 20Hz.

My full-range speaker system is essentially flat in-room to below 20 hZ. It’s odd that you believe otherwise without knowing anything at all about my room.

It is easier and safer to correct a subwoofer than a full range system without overloading either the speaker or the amp.

That depends on so-ooo many variables. I’ve used my speaker system safely for years with no issues.

... If I delete the subsonic filter from the program it ia mass pandemonium. It looks like the drivers want to jump right out of the cabinet. It is just inherent in vinyl if you have a good system capable of reproducing deep bass.

Oh no, that’s not inherent to LP at all. It’s true that woofer pumping can be common with improper setup or inferior equipment, but it’s not inherent to LP playback.

I have no subsonic filter at all in my system. The bass goes down below audibility to frequencies that can only be felt, not heard. No woofer pumping. Ever.

I guess I should read more carefully. You have already done that.
Look at the pumping, irregular or confined to a certain frequency. 
If it is irregular we are back to subwoofer, filters and caps.

My subwoofers are corrected which means certain frequencies are boosted up to 6 dB. If I delete the subsonic filter from the program it ia mass pandemonium. It looks like the drivers want to jump right out of the cabinet. It is just inherent in vinyl if you have a good system capable of reproducing deep bass.

Cleeds, the problem is your room is not flat down to 20Hz. It is easier and safer to correct a subwoofer than a full range system without overloading either the speaker or the amp. 

Last Lemming, just for fun try moving your rack three feet. Changing the position of the turntable relative to the nodes in the room might have an effect if it is feedback. Feedback will tend to be sustained and limited to a small band of frequencies whereas the woofer reproducing record warps and irregularities will be random. 

No fireplace in the room where the pumping occurred, but ironically in the room that does have a fireplace it doesn’t pump. 
Stringreen,

not sure I understand the question but the 4 surfaces I have directly coupled the TT to are:

concrete floorRigid stereo rack
heavy wood cabinet
on carpet

all of these surfaces produced the pumping exactly the same with 3 different TT’s and 5 carts. Also all these TT’s were moved around the room having the pumping issue and the pumping remained the same. 

In the other room where I don’t have pumping none of the 3 TT’s pump. 
So frustrating!

..just a thought.....is the table that your turntable is sitting on rock stable?

@ last_lemming, I have a funny question, do you have a fireplace in that room where the woofer pumping is going on. Because a fireplace can cause low resonant frequencies in a room. The flue pipe is the culprit. I hope you have good luck with the preifereal ring. Mike  :-)

I agree it has to do with the TT, but something is going on in one room that is not happening in the other and it has nothing to do with room or rack resonance. I’ve always had a weird hum coming from the electrical line in that room that I’ve always thought was a ground loop issues, but what if it is something else?
The only thing I can thing of is maybe there is some kind of electromagnetic interference that might be interacting with ll the different TT’s cart’s magnets. 
I do have a preifereal ring coming in, so we will see what happens there. 

@ last_lemming, What, atmasphere said yes!. Plus component three the (room.) As you said, the same equipment and rack in another room doesn't cause pumping.  :-)

“When you have eliminated the impossible, whatever remains, however improbable, must be the truth?” — Arthur Conan DoyleTime to call in an exorcist.(Sorry for the flippant reply, but you have me stumped on this one.)

Larry,

I know it’s the TT per se, but it seems like some sort of interference is ramping up the pumping, because it doesn’t pump in the other room in the same set up - TT, cart, rack.

to you comments:

1. I have bought the ring. Hasn’t arrived yet
2. I have bear claws on a maple shade wood block, with the original prime feet secured to the wood block.  I have removed all these feet and tried various racks and also a concrete floor and carpet. Pumping is exactly the same in this particular room. Even on quiet passages. 
3. The TT is FURTHEST away from the right speaker where the pumping is worse. BTW the right speaker pumps more on all three TTs with 5 different carts and 3 different alignment methods. The pumping is exactly the same in all the different configurations. 4.  I did download a vibration program, but it must not be sensitive enough since the line is perfectly flat even on the most sensitive setting. 

tablejockey

... members who have their table setup dialed in, no rumble filter and use sub(s) ... you can actually play any LP, CRANK the volume, and you have ZERO woofer pump?

Yes.
To be fair, I don’t use subwoofers - I use a full-range speaker system that is essentially flat in-room to below 20hZ.

@last_lemming, I'm having a difficult time in reconciling the findings with the EMI hypothesis.  That the pumping only occurs with a turntable, is worst at the periphery of the record, and is reduced by 30% when the preamp is put into mono mode all indicate to me that it is a mechanical resonance issue.  Maybe the best thing might be to start with the basics and go from there.  If I remember correctly, the table you normally use in the room is a VPI Prime.  I would start with that and put it on the shelf without any added isolation platforms or aftermarket feet, etc. and get a sense of the resonance level.  I would then try what I think will be most effective mechanical remedy for reducing the pumping and that would be a periphery ring in concert with a record weight.  The VPI ring, at least, is designed to work in concert with a weight not with a clamp (as @mytthor mentioned),  If that eliminates the pumping, great.  If it diminishes it but doesn't eliminate it, I would then try an isolation platform or a foot upgrade and see where that gets you.  If these mechanical remedies don't cure the problem, then the next step would be wall mounting.  Given that the pumping is worse in the right speaker, I would put the wall mount over to the left.  If all of those mechanical remedies don't solve the problem, then I think the only alternative is to go with a subsonic filter.  BTW, I had suggested in an earlier post that you try to measure the vibration directly.  I have an app on my iPhone called VibSensor that does that.  I'm not sure if it's sensitive enough to pick up vibration on your platter but it would be worth a try.

What I'd like to know is-members who have their table setup dialed in,  no rumble filter and use sub(s).

By the reports of some, you can actually play any LP, CRANK the volume, and you have ZERO woofer pump? 

Sorry guys.  It’s NOT THE TT’s. All three do it on all different rack types. There is no way you get the exact same results on three different TT’s, sorry, that’s not the case here. 
Is not induced by the music. It happens on quiet passages. No music to cause pumping. 
I believe it’s EMI or similar. 
That being the case how can I track that down. 
Remember in one room the same TT and racks reproduce pumping and in the other, with all three TT and in the same rack I don’t get the pumping. Again, on quiet passages. It’s not a physical manifestation, it’s electrical. 
But thank you for your responses. 

Last Lemming, Millercarbon is correct; unfortunately, it is the turntables' interaction with the listening space. I had a similar experience with my turntable a few years ago. It was an Oracle Delphi Mk II with an SME V arm and Benz Ruby 2 cartridge. The entire setup was placed on a Target TT-1 wall mount turntable rack, mounted into the studs of an exterior wall. Oracle Audio pioneered the record clamp back in 1981. I installed everything myself, with much help from Wally Malewicz. After an exhaustive trial and error process similar to what you did, and contacting Oracle several times, it was discovered that the SME V requires a different suspension spring configuration than those typically shipped with the standard tune-up kit Oracle sells to keep the Delphi operating to spec. Once the correct springs were placed in the correct suspension towers and properly tuned, ZERO woofer pumping.

The woofer pumping occurs from acoustic feedback, resulting from the turntable suspension not being properly tuned for your combination of tonearm/cartridge, and/or your room’s resonant frequency. I know that the VPI is a "suspensionless" design; however the feet are made of different resins and polymers designed to filter out unwanted frequencies, but just aren’t doing a complete job of it. The Pioneer is even less equipped to do so. I have since upgraded to the Delphi Mk V in African Black granite, which has a platter mat made of vinyl resin concavely ground so that when the record is clamped it does exactly what the design of Millercarbon’s rig does, presses the record so that is is flat across the playing surface. You will NEVER get the same result from a record weight alone. You can achieve a similar result by utilizing a weight AND the peripheral ring clamp on the VPI; they are deigned to be used together. One other thing that may help, get yourself a shelf for the turntable to sit on that is decoupled from, instead of mass loaded to, the environment. Again, note Miller’s setup. The Black Diamond Racing Shelf for the Source is an outstanding device, albeit expensive. I am using a Z-Slab from Zoethecus (unfortuantely defunked) on top of a 1" African Black Granite slab in the TT-1 instead of the stock shelf. Yes, that’s a whopping 105 lb mounted to the wall. The Z-Slab/Oracle Mk V is supported by weight appropriate discs from Grand Prix Audio, and this has resulted in dead silence, from a turntable sitting 4’-5’ on the side wall from a F-13 Fathom sub and M-L Ascent i speakers in a 14’x11’ room.

Good luck with your journey. I hope that this will give you some direction in resolving this problem. I KNOW how frustrating it can be, but with perseverence, when it is resolved it will be SO worth it. Almost everything I play now is on vinyl even though I have similarly spent on digital for not only this one, but the other systems around the house. EVERY room has its’ own music system; it’s good for what ails ya!

But compatibility isn’t the issue. The same equipment and rack in another room doesn’t cause pumping.  

@last_lemming 

This is an important clue! This means its clearly mechanical feedback between the woofers and the turntable.

last_lemming, as you noted your equipment is fine and doing exactly what it was designed to do. You can either just  stick with digital, get a subwoofer (big drivers move less) with a high pass filter on your speakers or get a subsonic filter. The best subsonic filters are digital and part of a room control system which means you would have to digitize your turntable. You can also just stick a cap of the right size on your speakers, a very low frequency high pass filter. 

I bought a KAB subsonic filter and never looked back. High quality.

Muteur, 

It’s not about better equipment. My equipment is just fine and many people have the Same gear without any issues. 

Big greg

thats not the system that pumps, that one is the one in the “other room”. I don’t have pics in the Woofer pumping room. 

The same equipment and rack in another room doesn’t cause pumping.

Chances are it's placement.  You've got your rack sitting in a corner right behind a speaker.  And is that one of your Rel subs sitting right next to the equipment rack with the lamp on top of it?  Didn't we already go over this.

if you moved all the equipment to another room and the problem is solved then check AC line and grounding. also check AC polarity on all equipment (remote possibility).

still if you can not find any solution then use subsonic filter
or
if sound quality degradation caused by subsonic filter really matters to you then get better turntable, tonearm, cartridge and phono preamp.