Why are my woofers pumping?

If I were you, I'd start from square 1....make sure the cartridge suspension and stylus is ok.   I'd send it back to Lyra for a checkup.  They probably won'r even charge you to look at it.  The Atlas is one of my favorite cartridges....I've heard it in  V with a high end system with powerful low end and no woofer pumping.

>>>>>> I can see it, even if I don’t hear it. Why does it happen? The woofers behave normally (no pumping) with digital music, and when the stylus it lifted from the groove, so it is not the speakers, amps, preamp or phono stage. <<<<<<

In the day of phono only they had a button sometimes labeled "Rumble filter."  That's what you got.  Others may say "Low filter."  Interaction between the cartridge, tonearm and record cause ir.

Does your turntable have an attached cover? If yes, it catches low frequency audio like a sail catches wind. See if removing it reduces the feedback. If yes but you still  want to keep the cover attached, rotate it perpendicular to the speakers to at least reduce the pickup. Worked for me! Just a thought. - Andy

Whatever you do, don’t get a subsonic filter, unless of course you want to kill good sound.

This is nonsense. I use the cheap DB Systems filters and the loss in fidelity is barely perceptible.

I also discovered that, indeed, "silent" record grooves are not the same.

You discovered that subsonic noise is often cut into the grooves. This is why you're not getting pumping in the runout grooves. I once believed warps were the major culprit. They’re not. It’s usually acoustic feedback and poor album cuts

Read some of the reviews on these:

http://store.acousticsounds.com/d/60042/DB_Systems-DB_Systems_Subsonic_Filter-Turntable_Accessories

At only $20, it can’t hurt to try them. If you like the result, consider investing in the DB-12 or KAB filter.

+1 tkr and stereo5! A well designed subsonic filter (KAB) will do wonders for bass in your system! 

Thanks, all! I think we can conclude that

1) the Atlas / SME V combo is very “receptive” in the lowest frequencies, and that in some resolving systems this may give unwanted effects like woofer pumping.

2) this is mainly a resonance problem, not a rumble or player noise problem (it does not change much, with different platter mats, damping or stabilizing the turntable, etc), and the first measure is to try to move the resonant frequency up - reduce the effective mass of the arm. This is only slightly possible on the SME V, but even small changes may help

3) the somewhat "over-eager" reception at the lowest frequencies of the Lyra/SME combo makes it even more important to correct any residual system noise, drive noise or rumble.

4) if the problem persists, try a rumble filter.

I will now try to decrease system noise – check the turntable, bearing, oil, feet, etc.

I wonder, even if the pumping is already reduced, would a filter be an idea anyway? Are my woofers straining too much, in the lowest bass? Is this prone to happen more, when the suspension of the cartridge is more worn?

@o_holter - You mentioned earlier in the thread about an XLR filter. I was struggling with the same woofer pumping problem and finally commissioned Dan Satoni at DTS electronics to build a custom balanced high pass filter for me. Problem solved with no obvious loss of sonic performance. I know Dan has a minimum board order of 5 units so I am pretty sure he can quickly build another one for you if interested. It wasn't exactly cheap ($550 CAD) but I feel it was an exceptional value at that price.

Todd

VPI Classic 3 w/Lyra Delos -> Whest PS.RDT30 SE -> Custom Filter -> ARC Ref2 MkII -> ARC VT100 MkIII -> Magico S1

Please note that woofer pumping is not only caused by the cartridge/arm. Some CD's cause pumping as well. Hopefully you have a "low-cut" option. Use it only when needed.

Han_n - yes I will test this more. The "low cut" option may be what I lack.
Toddc2 - thanks, I have followed up.

I mailed an audio tech the other day, is it likely my woofers are getting worn out? Even if I don't hear clear problems? Answer: after five years no - it is not likely.

Some more pumping and woofer cone vibration testing today.

Pattern confirmed: the misbehaviour is less than before, but still noticeable on very high volume. There is some subsonic pumping (I can see it but not hear it).

The interesting thing is: it happens at certain intervals per revolution of the record (playing silent grooves between tracks). If I turn up speed to 45, the pattern is repeated, only faster. This seems to indicate that player rumble or drive problems are NOT the main issue. The platter on the Hanss T-30 is perfectly levelled and revolves smoothly – the pitch is steady, there is no sign of imbalance or distress, and almost no perceptible vibration noise touching or stetoscoping the plinth.

So if the player is mainly fine, the answer must be that the cart/arm combo picks up “vinyl noise”. Please correct me if I am wrong!

Could this “inherent vinyl noise” be most strong down around the resonance frequency, at ca 7 herz?

I am investigating different filter options, with helpful answers from KAB and Satoni, thanks to your advice. Since I have invested in a balanced system (from the phono stage to the amps) I am not so keen to go back to single ended connections from the phono to the preamp, although this would be the easiest (and cheapest) way to know if I am on the right course – if a rumble filter would help.  

o_holter

Some more pumping and woofer cone vibration testing today ... still noticeable on very high volume. There is some subsonic pumping ... it happens at certain intervals per revolution of the record (playing silent grooves between tracks). If I turn up speed to 45, the pattern is repeated, only faster. This seems to indicate that player rumble or drive problems are NOT the main issue.

That actually sounds very much like a drive problem, such as a bearing issue or bad belt

.... Could this “inherent vinyl noise” be most strong down around the resonance frequency, at ca 7 herz?

I don't think what you're experiencing is “inherent vinyl noise.” I agree with @stringreen - it would be a good idea to start at square one and have Lyra check that cartridge. Did you buy it used? If so, it's immediately suspect, even if it isn't your only problem.

Before going on, I need to tighten the center shaft (with the magnets) to the plinth on my Hanss T-30. It is fastened by four screws from the underside of the plinth. Does anyone know the type and dimension? The screws are very hard to see unless the player is placed on the side. Thats a heavy and somewhat risky job, so when I do it, I need to have the right tool. The Hanss manual does not specify the type of screw, but they have confirmed that the shaft should sit tight. ("shaft" maybe not the correct term - I mean the cylinder that the spindle sits in.)

Tighten the center shaft - meaning: the housing of the spindle.

cleeds - thank you, yes I bought the Atlas new and it shows no obvious signs of wear so far.  You are right, it may be a spindle / bearing problem. So I want to eliminate this factor. I have a friend with a T-60 who may help me fix it, soon.

Resonance - a red herring? If so, reducing effective mass on the SME V may not be a good idea (+1 to Atmasphere, and others, for setting me on this track).

Therefore I thought, OK, let me go back to a normal setup of the arm. I screwed the upper bridge back on and adjusted the counterweight back so the spring weight does the job alone, tuning it to the 1.72g recommended for the Atlas. Then I checked, using the runout on R L Jones The evening..., on the same very high volume level as before. Did I see more subsonic cone movement / pumping? NO. Slightly more energy, touching the cones? MAYBE but not much. What strikes me is that the "tone" of the vinyl noise has gone down a bit, it reaches lower in frequency. (Usually a good sign, says my audio intuition).

This test result does not rule out a "demanding" combo that can easily pick up too much lowest-low frequency. Maybe there is a herring. But its not red?

Since the problem is mainly gone, the thread should end soon. But it would be nice with a conclusion. I had woofer pumping, I changed some things in my system, and then the pumping (or most of it) went away. Why? Not clear.

Maybe the most likely reason - for now - is that I took out the platter and reinstalled it, with a little change of the ball and spindle position, making the drive work a bit more smoothly.

However my "audio intuition" is not quite satisfied with this explanation. The pumping error seems more like a yes/no proposition, as if you throw a switch - it is there, or not there - maybe mainly resonance-related (or even electric, e g could it even be influenced by static electricity?). So far I have not been able to reproduce the error. So I dont know exactly what makes the woofers start pumping. But it seems fairly clear that if it was only the drive, or player imperfections, the pumping / rumble problems would have been much more constant. 

@o_holter

I too had reduced my woofer pumping with each of the following steps:

1. Cartridge setup tweaked by my VPI dealer
2. Replaced my cartridge
3. Added a Symposium Seque ISO platform
4. Added Symposium VPI footers
5. Added a custom 2" walnut platform sitting on RollerBlock Jr’s under the Seque
6. Swapped my Quadraspire Q4 Evo rack with a Massif Audio Design rack (no obvious change)
7. I have an older Classic 3 and tried damping the arm with VPI damping oil, that didn’t help...

Each of these changes reduced the pumping (well, more or less) and a couple of times I thought my issue was resolved. I think your intuition is probably correct in that this problem might not be resolved.

PM me if the problem returns, I might be open to sending my filter out for you to try.

Todd

I've had that same issue. I bought the rumble filter....it degraded the sound and didn't cure the problem either.
I actually had a post on these forums and someone recommended moving the turntable away from the speakers.
I moved my speakers out into the room as much as I could and the problem was solved. I now rarely get this to happen....and when it does I lower the volume a couple notches and it goes away.
I'm convinced that if I could move the turntable completely away from my my speakers...there would be no issues.
The issue is with your cartridge and speakers. That's my opinion.

The Atlas sounds real good, now, with 100 ohm loading (+1 to Atmasphere). Playing Nik Bartsch: Continuum (great sound) for example, but also older overlooked classics like Joe Walsh: No peace in the city. I love this cartridge. The woofers are energetic, yes, but I cannot see much pumping.
 
Toddc2 - this reminds me of all the tweaking I did with my VPI HW19 - every little bit helped - sand box - ceramic cones - name it. I will take you up on your kindly offer to try the filter, if the pumping persists.

krelldog - I see what you mean - and I also position my speakers quite far into the room. I think best practice is to move the whole stero system away from the wall behind the speakers but thats not very possible, in my case. Which filter did you try?

The interesting thing is: it happens at certain intervals per revolution of the record (playing silent grooves between tracks). If I turn up speed to 45, the pattern is repeated, only faster. This seems to indicate that player rumble or drive problems are NOT the main issue.

Boy, that sure sounds like a drive issue to me!

But it sounds like this is mostly solved :)   I would put a drop of oil on the platter bearing for good measure...

I think it was the KAB filter....or something similar to that.

I'm not saying its not a good product....it just didn't work for me.

@o_holter

It sounds as though your setup adjustments might have reduced some cartidge resonance. I’m thinking that was likely part of the problem.

And in answer to one of your questions, yes, sometimes subsonic noise is actually pressed right into the grooves. It can result from multiple steps of the vinyl manufacturing process. It can also result from warps but that is a problem more often associated with stable balance tonearms, such as some uni-pivots, as their tracking force changes when they traverse the warps.

So there’s many factors that can lead to woofer pumping, but only one ironclad solution: a rumble filter. It will only be a detriment to the sound if that is your expectation. For every one who claims they alter the sound, there’s probably a dozen who claim otherwise.

I own the KAB Rumble Filter and I am one of the ones that claim otherwise.  (No change in the sound!)

@o_holter : Again:

https://forum.audiogon.com/discussions/why-are-my-woofers-pumping/post?postid=1551771#1551771

With all respect to those gentlemans that insist on the KAB filter or the like please ask you: who of them owns the Atlas or even listen that kind of very high quality performance levels?

Seems to me that no one of them because they are not taking in count what really means: quality level performance at the Atlas levels- They say that with the filter they almost did not listen degradation and this just makes no sense.

R.

Almarg 4-24-2018
... given the unusual design of the turntable’s drive mechanism (comprising six belts, three of them driven by what is apparently a synchronous motor on one side of the table, and three of them driven at a different height by a similar motor on the other side of the table) ... the platter might be being driven in a slightly uneven and/or not perfectly level manner. Perhaps simply due to the condition of the drive belts differing slightly between the two sides.

And I note from your system description thread that the table appears to be around five years old. Perhaps all that is needed to resolve the problem is a new set of belts?


Cleeds 4-28-2018
That actually sounds very much like a drive problem, such as a bearing issue or bad belt.


Atmasphere 4-30-2018
Boy, that sure sounds like a drive issue to me!

Consider replacing the belts!

Best regards,
-- Al

Correction: the Atlas has a 121 ohm load (not 100) - and sounds fine.
Replacing belts - yes, new ones ordered.
I will give the spindle a drop of oil, and fasten the spindle housing when I get the right tool.
BTW, reading up on the Hifi News test record shows that people find a lot of problems with it. On the lateral resonance test the actual test tones are different from those stated. I know from before that the record's anti-skating test is not good, in my case at least.
Some years ago Michael Fremer reviewed the Kuzma 4-point with his Lyra Titan i cartridge, pronouncing it the best arm he had heard so far. But using the calculators, resonance is down to ca 7.2 hz. Even more problematic than with the SME V (ca 7.5), since the 4-point weighs a bit more. Yet it wasn't a problem, to his ears.

Hi Raul, thanks, I reread your former post, where you wrote: "even at 100hz the Atlat compliance and effective mass puts the resonat frequency in a " solid " 8hz."  I get results closer to 7hz (arm mass 10.5, screws 0.5, cart 11.6g). It all depends on what we assume is the 10hz measured compliance (supposed to be x 1.5 to x 2 of the 100hz measure - 12 in the Atlas case). I have to assume a compliance of 17 to get above 8hz. I have found no exact Lyra specification. So this is really "blind", especially if we assume - as some do - that small variations in resonant frequency play a role, at the margins at least. I get confused by all the web debate on this, "fundamentalists" who say resonance is of key importance, some who say it varies with the type of arm, player, and what not, and some who simply dont believe in it (at least not with modern fairly "medium" cart/arm combos).

Likewise, I can find no objective measure of how much the resonance increases, by adjusting the static counterweight so it does all the lifting on the SME V, compared to using the dynamic spring mechanism (but a lot of debate about how the dynamic may sound best and be more kind to the cartridge). I do see the point of Lyra including light weight alu screws (among several types). Regardless of their problems, both the Hifi record test and the calculators indicate that the arm could be lighter.

So - back to the ears? Only listening can really be the judge? Test records not correct, calculators failing to take into account important parameters  - like the arm stiffness - you name it.   

Some of you have suggested that acoustic feedback may have played a role for my "woofing" or woofer pumping.

This is relevant not least in a four speaker system, like mine, where some drivers are pointed towards the back wall  (with the record player).

I tested a bit more, playing the new 2 x 45 rpm Jefferson Airplane: Volunteers. Volume: loud. This is a very good remaster, quality pressing, low vinyl noise. I hear this on the grooves between the tracks. When the tracks / music played, I used my stetoscope on top of the different parts of the player.

The results were interesting, more varied than I would have thought. The top of the maglev feet had next to no feedback, the sound was dead. The plinth, and also the motors, had more feedback, although I did not hear clearly "wrong" or exaggerated sound. I tried to "hold on" to the plinth, firmly, as suggested in the thread above. It made no difference.

I would like to test the platter and the record clamp, but since this rotates, I can’t do it with a stetoscope. Anyone knows of a phone app to test for rumble or noise, laying on the platter?

Since this thread is getting over and finished - the woofer pumping has stopped - I will only update if I find some clue, what the problem was. So far, I have not been able to recreate it. Maybe it was caused by a troubled spindle - not quite in place - or other drive problems, as suggested by vpi and others, above. Obviously, the slight leeway between the spindle housing and the plinth, which I need to tighten, may play a role, but in practice I don't think so, since due to the 10 kg platter weight, it settles quite solid anyway, and I cannot reproduce pumping by pushing the platter (or plinth).

I note an interesting thing, checking the player, and cleaning the belts, pulleys and platter. The Hanss uses two very silent motors, not vibrating much. But when I touch the top pulleys, slightly with fingertips, the vibrations are more notable. Sometimes it seems as if the motors develop a "trouble" position with the pulleys straining and vibrating. I can reduce the vibrations just by moving them a tiny bit. This is a behavior I recognize from my VPI HW-19. The motor / pulley does not quite "stall", but a combination of energies has made it stressed. Anyone who recognizes this pattern?

@o_holter The studder you are seeing in the spindle is typical af asynchronous motors and not a malfunction.  Download and read the manual for the VPI HW-19 MK 4.  There is a paragraph that explains this.

If your woofer pumping returns do not use a filter.  You would just be covering up the problem instead of solving it.

in the meantime, enjoy the music.

Thank you vpi. Always something new to learn.

Some more testing. The woofer pumping problem is still there, maybe a bit reduced, but not fully solved (sorry for too general statements above - I thought it was solved). It is very dependent on the record - some LPs have more, some have less. I am investigating whether a filter could be an idea, using a laptop and a sound card to see what goes on in the low hz region (through the program Audacity).

vpi, and others - two camps in this thread, "fix the cause" or "fix the problem" - if I want to fix the cause, and change the tonearm, keeping the Atlas, although I dont have the financing to do it now - what would be a good match, with a resonance around 10 hz? That sounds good with the cart?

One more test. Changing the connectors from the Aesthetix Io phono stage to the Einstein preamp from balanced to single-ended. Result; much less woofing with single-ended. But much poorer sound too! More flat, congested, less involving. Even when I turn the volume up, to get the equivalent decibel level (which I have to do, for the single-ended connection), there is less "here-ness" to the music. I have a semi-balanced phono stage - balanced from the second amplification section through the output. The balanced outputs sound way better than the SE / RCA outputs. Conclusion: a single ended filter like the KAB probably will not work for me. Running the phono signal single ended, or through a single ended tape loop, will degrade it.
Cables used for testing: 1) balanced - JPS Superconductor 3 (very good xlr cable); 2) single ended - Kimber KCAG (very good in some applications but not here).

Status: I enjoy my SME V / Atlas combo, even with some woofer pumping and - maybe - possible distortion. Yesterday I tested Kula Shaker: K2, on LP vs Tidal digital. Result: digital = no clear woofing (as before), but poorer sound. Distortion - some, very evident in loud music passages, from both sources, but overall more "grunge" in the digital. The contest was a bit more even, than I remember - analog does not totally outcompete digital, but still, no doubt. I should probably consider a better DAC. But if it has real "grunt" (like the Aesthetix Io) maybe this includes some woofer pumping ;-  If you cut low frequency it easily hurts ambience, overtones, etc. I think this is why Pink Floyd's Echoes has woofer pumping. Everything down below is recorded. The vinyl is taxed to the maximum. You can hear this deeper tonality also in the high frequencies (Richard Wright playing light organ touches). With today's resolving systems, we are able to reproduce such pioneer enginering efforts and should be grateful for it.

You keep coming back to the KAB, then diss it.  Why not get one and try it?  If you don't like it you can send it back.  I use one in my system and my 3 audiophile friends and I could tell no difference with or without it other than absolutely no woofer pumping.  The Turntable is a VPI Prime with a ZU-Dl103mc cartridge, VPI interconnects going to a 7K McIntosh tube preamp.  Speakers are GE Triton Reference.  Like I said, problem solved and I can sleep at night.

stereo5: I don't diss the KAB. I am only saying, single-ended cables from my balanced phono stage to my balanced preamp sound much poorer in my system, compared to balanced cables. So a filter, to become a plausible option, would have to be balanced. The KAB, in the current configuration, is only single-ended (RCA connectors). OK?

I have been in contact with KAB and another filter maker suggested earlier in this thread. They have responded very well and informatively. 

Two camps appear: the "purist" who say: fix the problem, and the "lowly ones" (plebeians) who suggest a filter "to be done with it".

Pink Floyd LPs  - a  quick test of woofer pumping
1 The original LPs from the first years, not so much, deep sound is not recorded.
2 Notably more deep sound - increased pumping - overall sound is better - step by step - on Atom heart mother, and early 70s LPs - reaching a climax on Meddle
3 Less woofer pumping but also somewhat limited, anemic sound on my remasters of Dark side of the moon  (i dont have the original here)

Another KAB RF-1 user with great results.  VPI Aries 3, Ortofon Cadenza Black MC, Manley Chinook SE, McIntosh pre and amp, Sonus faber Cremona Auditor Ms, REL B1.  Glorious music.

+1 miner42

Just a thought, what if you used RCA to XLR adapters? BAT makes some excellent ones. I have an original Harvest first pressing of DSOTM and the bass is very taut and very deep with no woofer pumping.  I also have a MFSL pressing which for some reason is much lower in volume with no pumping.   I wish you lived close by, I would let you borrow my KAB filter to try.

Thank you miner42 and stereo5. It may take some time, but i wish to try your suggestions. Although changing the arm or the cart might be optimal, no one so far knows for sure what works best in my system. 

I already know that using single ended outputs from my phono stage curbs the pumping compared to using balanced outputs. But it also sounds much poorer! So to give the KAB a fair chance it would need an xlr to rca adapter (thanks, stereo5). Not sure if an additional adapter is needed to the Einstein preamp it seems xlr and rca inputs sound the same.

Listening to vinyl rips from main system, on my cottage system. No pumping of course - the Aurum Cantus speakers only go down to 40 hz or so. So music is limited but it also sounds nicely peaceful. No harm done - sins of omission not commision in the bass.

I think beyond the low cart-arm resonance we need to add the very fullscale speaker system in my main system. Four speaker Audiokinesis. Lots of woofer power. - Maybe other speakers is why some users and reviewers dont experience much problem.

Electronics bandwidth is an issue too- your amps are full power to 1Hz. Most tube amps can't go anywhere near that low.

But I have similar bandwidth with both the amps and speakers at home, yet don't experience this issue. I am using a Triplanar, which allows for a bit of adjustment of the mechanical resonance by using multiple weights for the counterbalance. My 'table is different too.

Its true that some lathes can impart low frequencies to the LP, but that usually occurs between tracks and also at the end, where the carriage for the cutter head is advanced at a higher rate than during a cut. It sounds like you are getting this pumping during cuts on the LP, so I would rule out the LP as the source.

I would try applying a light grease to the platter bearing, to see if it shuts it up. If so, I would be thinking that the platter bearing is worn as normally a light oil is used.

Thanks Atmasphere - yes the low reach of the amps in combo with the speakers  may play a role. But with the Triplanar you dont have the problem. Do you know the resonance of your arm cart combo?

Lathes - low frequency - ok - but if it happens between tracks why not also within them? I can see the pumping between tracks on my 'energetic' Lps. Not much within the tracks but i think this is because the music energy takes over the woofer. It does not show much but is still there. Giving more stress in the music. Just my suspicion.

Since degree of pumping varies with the LP and repeats precisely with the record's revolution, drive problems probably is not much involved - confirmed by cleaning belts and adjusting the player - no big difference.

I notice that Pink Floyd Echoes recorded from the LP on my system pumps the woofers also on my cottage system! 

O_holter:  I'm convinced your problem comes from acoustical feedback. With a TT, placement is vital. I too had the same problem.  After months of experimenting, I found that TT platform isolation cured my problem. I built a suspended platform using heavy duty dampened springs and cables. (my room is on a suspended floor on the upstairs portion of my house that exasperates the problem)  I also noticed feedback on my Theta Miles CD player, when playing anything with a lot of elf and high db levels. I installed four steel cones on the bottom of the player and now I enjoy outputs of 90 db+, without any adverse effects on both playback systems. Most rooms have areas, where the low frequency is somewhat exaggerated. Be sure your TT, as well as your CD transport is not in one of these locations. 

I am mystified. Why do i see woofer pumping playing Echoes on my small cottage system which is 6db down at 42hz and probably not audible below ca 38hz? All hail to DSD? I play a rip / recording of the same original vinyl that gives pumping in the main system. Recorded in DSD on Tascam Da3000. Playback by the little Fiio x3 player, which does native DSD, to a Ming Da integrated tube amp and Aurum Cantus Leisure 3 SE speakers. All very good but i seriously doubt if this system is capable of doing anything down at 7hz where my cart-arm resonance problems are.

Handymann - much appreciated and relevant. I did a lot of platform and feet mods with my Vpi Hw19 to good effect but mods have so far little effect on the Hanss t30 with its maglev feet. And - my vinyl recordings are made with the main speakers silent or very subdued. So I doubt acoustic feedback is the main culprit in this case.

The woofers on the Aurums are smaller but the behavior is similar to the Audiokinesis woofers. Some sound related vibrations but also pumping in and out. Yet I dont hear this movement at least not directly. Using my fingertips there is energic quick vibration that I hear but also a slower pumping that i dont hear. 

 Listening more, the experimental nature of Echoes and the whole Meddle album shines through. In other words it may well be that they experimented also in the low frequency range. They used Shepard tones and invented seagull squeals, I read. It is one "flowing" album and the silences between the tracks are not just silence but e g wind blowing too like at the start.So it is maybe a quite special case.

I had significant woofer pumping

https://forum.audiogon.com/discussions/rumble-issues-see-old-thread-update#1559764

Tried everything

then did the feather test

a light feather should be able to move a tone arm

the bearing in my tonearm wasn't moving vertically

all the movement was the cantilever going up and down creating the woofer pumping

Audiotomb - very interesting. I think my arm floats fine but will check when i get home. The HFN record lateral test shows very visible and sonic resonance ca 7hz while the vertical test is much less obvious (the test tone warbles a bit between ca 10 to 5hz).

"If you have rumble problems, get a light feather!" Who said this hobby was boring?

Update: situation in the system at the cottage seems like with the main system at home. Vinyl records including DSD recordings of these made by the same cart-arm-phono-preamp in the main system, create pumping, more or less. Its not just Meddle, but e g Glass and Shankar too and Sade: Love is... When I play digital from the Oppo player I have here - no pumping so far at least, testing SACD Moody Blues: On the threshold, and CD Spirit: Sardonicus.

There is pumping with vinyl but maybe it disturbs less with the smaller speakers and less linear amp here. I also note that there are more energetic vibration from the vinyl (slightly touching the cones) compared to the sacd and cd. My ears tell me I prefer vinyl - this is why i bother to make recordings. 

It seems that to use the single ended Kab filter from the balanced outputs of my phono stage (having tested that these sound better than the single ended outputs) I will also need a converter box. It becomes complicated.  If KAB was next door of course I would have tried it by now, but it means shipping across the Atlantic and maybe taxes just to have a try. Kevin at KAB has been helpful.