So Weird- No Stylus Contact Woofer Pumping with Hana ML and Elac PPA-2

I’d say that’s the highlight 

Apologies not necessary.  Suffice to say you found a glitch in the wiring and fixing the glitch also cured the woofer pumping.  Is that a fair summation?

Also- you were right about the AC- it was going positive and negative, slowly but plus and minus none the less. Apologies.

I understand that resistance is additive in series. So in one sense there is no possibility where there would be an EM potential difference. However I saw on the o-scope various differences between the left and right channels that increased in amplitude as I lowered the input frequency. I figured all this was reactive- an impedance change. Also it was disappearing in single end- linking the ground fixing the problem, at least as I understand it. I was in the Submarine service and got a nice commendation for recommissioning a failing hovering system, it was a corroded solder joint. That’s how I got to a garbage solder joint as the possible cause. Change wire, add solid connections- problem gone. I figure someone in 2056 will have this trouble and thank me after I’m dead.

I'm stumped. What do you reckon was the mechanism of your original observation? Which is to say how do you suppose the wiring fault had something to do with the woofer movement?  I am not at all challenging you or trying to contradict you; I am just truly curious, even though I do not doubt that you may have had some bare wires somewhere in your arm tube, if that is what you are suggesting.

By the way, I too tried to work with the Audio Note silver Litz, and I too used a solder pot.  I melted more wire than I soldered, and in the confusion, the four wires got hopelessly entangled with each other.  It's a job for a pro who preferably works with that wire every day.

SOLVED- Short answer, my fault. The Audio Note silver litz is notoriously difficult to work with and in this case my reach exceeded my grasp. The o-scope trace of the left vs the right channel was different by about 15%. I figured there had to be something there to explore. I desoldered the wires to take a look under the microscope and saw very few clean areas free of urethane. Every connection point was wildly different.
 

I picked up an el cheapo solder pot so I would theoretically have an advantage clearing the goop. The trouble with el cheapo Amazon solder pot is that the temp controller swings too wide. Just when a wire was almost there- zap- melted in the pot. I need 13” of wire and at some point my second wire ended up at 12”. No more Audio Note wires.

I reinstalled the original Mogami set. This was designed for MC cartridges and despite my concern for the mass that the original setup adds, with the Hana ML it worked out to a tone arm resonance of 10 hz. The original set is copper and unlike the Audio Note it’s obviously larger than a human hair. It has the added advantage of existing within my skill and equipment set.

At any rate, the effect of static on the cartridge is gone. To be honest the circa 1970/80’s wiring sounds very good. I had originally pulled the factory set because it’s curiously heavy and the mass was too much for a 2M Black, I also suspected an electrical mismatch in design.

The PPA-2 using balanced input and balanced output is a different animal than in single end mode. It wipes the floor with its unbalanced self. More transient energy by a mile. It really comes alive.

This thread is solved, if nothing else, if someone else tumbles into this scenario it may help.

Somebody asked for a video of the o-scope display

Enjoy

https://youtube.com/shorts/O9GJToBeZAk?feature=share

Also I input square waves at the phono cable end and scoped the cartridge end with the cartridge connected- all square with the left and right showing a slight amplitude difference. My next plan is to try to bypass the arm and phono cable wiring with an alternate set up mounted external to the arm to see if the problem repeats.

I reinstalled the XLR and using the Hi-Fi news test record 300 hz bias test track 6, just for the 300 hz signal, I again got the woofer pumping. The signal rides the rising and falling baseline. With the cartridge lifted but over the record the signal is flat, rising and falling. 

Weekend results- using a signal generator I input square waves into the phono pre at all three possible inputs, input 1 RCA, input 2 RCA, and input 2 balanced XLR. All three output clean square waves at normal operating frequencies at various amplitudes. I couldn’t trip it up. So I’m eliminating the preamp as a culprit.

Nothing that has been offered as solutions seem viable. Static is random, forget about it. The only suggestion that makes some sense is the the possibility on a weight sensor on the table to detect record weight. The Achromat is much lighter than the rubber stock mat on my old SP-15.

Agree @waltroman - but ignoring a solution, how does the static manifest itself into the signal wires?

I would think that both the + and - wires would be elevated equally and in the balanced sense they should then cancel out with the CMRR of a balanced approach.

Nothing that has been offered as solutions seem viable. Static is random, forget about it. The only suggestion that makes some sense is the the possibility on a weight sensor on the table to detect record weight. The Achromat is much lighter than the rubber stock mat on my old SP-15. 

Holmz, I have been saying forever and I’m sure ad nauseam that I don’t think it’s DC. So if you’re addressing me, you’re preaching to the converted. We agree.

@lewm It is not DC… by definition is like a sine wave or really more like a wavelet that is at a period of 33.3/60 of a second.
However it is maybe not a 1/2 Hz sinewave, more likely it is a flat line, with a heart beat that is happening over a just a fraction of the 360 circle.
So maybe it is a 5 or10 Hz thing that happens “at a rate or period” that is 33x/minute.

If it was DC the cone would be pushed out, but the cone was “pumping” and that is a verb or action word that describes something that is not steady-state… and not what a blocking cap or servo is designed to control… assuming that they are used for steady-state control.

…. So, I am dubious that DC generated somehow from the cartridge is causing the problem. But it did occur to me today that maybe the servo in the OP’s preamp is defective when operating in balanced mode. All bets are off.

The thing is perfectly synced to the platter, and the signal has to be coming from the cart, or has to be coming from the ground.

There is no other way the phone stage etc can make the speaker pump perfectly in sync with the platter.

Maybe it could be an intermittent DC shift on the ground, but the “no vinyl” “No mat” discounts that. And a servo will not remove it.

it is a conundrum.

Like I wrote above, my research tells me the OP's preamplifier avoids use of a coupling capacitor by virtue of having a servo mechanism to balance out DC offset at its outputs.  Right there, that ought to prevent DC from getting to the woofer.  But if one wants to insist on a DC origin, then you have to postulate that the DC is somehow getting by the servo mechanism and also that it is pulsatile in nature, either pulsing between positive and zero or between positive and negative with a 180 degree phase difference, in order to make the woofer move as we see it moving. I mentioned that such servo devices are usually very effective in blocking DC.  My Atma-sphere MP1 uses such a circuit to avoid the need for a coupling capacitor, and I have measured DC offset at no greater than 2mV.  That is not enough to move a woofer, even if all of it did get straight through the ampifier to the speaker.  Some SS amplifiers do pass DC, but they don't amplify DC.  So, I am dubious that DC generated somehow from the cartridge is causing the problem.  But it did occur to me today that maybe the servo in the OP's preamp is defective when operating in balanced mode.  All bets are off.

Constant DC of one polarity will eventually damage the voice coil.

Only if the DC wattage is enough to cause the VC to rise beyond its temperature capability. A small amount will only slightly warm the VC… R*I = power and those electrical watts are the same as thermal watts.

I suppose intermittent DC pulses could appear as if a low frequency AC source, but….The question is whether the preamplifier and amplifier can pass DC from the TT to the speakers. And DC of sufficient magnitude to move the woofers.

Yeah we talked about blocking caps back on page 2 or 3.

And now whether the frequency is low enough to use a blocking cap to also block close to DC would likely work, as the excursion is not really heard. But maybe some doppler distortion can happen? 

Since we do not know the causal mechanism, we are sort of jumping the gun for a solution, as we do not understand how to ameliorate the causal mechanism without knowing the causal mechanism. 

I do not think we need to know the amp, as the system does it only with XLRs and the RCAs do not exhibit it.

So it is most interesting thread in ages.

Ughh.. Holmz, DC will move the diaphragm in one direction only, yes. Constant DC of one polarity will eventually damage the voice coil. I suppose intermittent DC pulses could appear as if a low frequency AC source, but….The question is whether the preamplifier and amplifier can pass DC from the TT to the speakers. And DC of sufficient magnitude to move the woofers. His preamplifier uses a servo mechanism to cancel any DC offset at its output. (See review by Fremer.) I don’t know what amplifier is in use but many block DC. Any coupling capacitor in the amp circuit would suffice to do that. (Amp may have been mentioned but I’ve forgotten.)

… DC into your woofer might burn up the voice coil but won’t move the diaphragm…

@lewm

That is false… DC will make a constant magnetic field that will then push the diaphragm off center.

It would need to be a pretty high offset to deliver enough energy to move it to overload the woofer thermally.

If it is not moving the diaphragm, then there is no AC and no DC.

Whatever the source is that’s moving your woofer it is an AC signal doing the work..

Yes AC, but AC that is at a low frequency.
Hence my earlier suggestion of a DC blocking capacitor, which blocks low frequencies.

But the freqs needing to be quashed, maybe higher than 20Hz as the table is turning at ~2Hz and the think is rising and settling over a small angular extent.

The problem isn’t solved really. That woofer pumping should not occur to that extent. I believe there is a problem with the ELAC PPA-2 balanced input. Both single end inputs function fine. I’ll be looking into it this weekend. I bought to unit on US Audiomart so no warranty for me.

Even more troubling @mitchellcp is that the causal mechanism is not known.
It would be interesting to try another phono stage that is balanced to help identify you hypothesis of the ELAC. But it seems like a rational conclusion.

A pragmatic person might just chuck in the RCAs.

The problem isn't solved really. That woofer pumping should not occur to that extent. I believe there is a problem with the ELAC PPA-2 balanced input. Both single end inputs function fine. I'll be looking into it this weekend. I bought to unit on US Audiomart so no warranty for me.

Two lollipops then.

"No insult was intended."  MY point.

Would you like a lollipop to make you feel better?
 

My point

"I find a subset of people in the Analog section of the board who are terse, unhelpful and impolite if not outright rude and insulting. What could be more unhelpful than to present, as a fact, something that simply false."

Would you like a lollipop to make you feel better? I made an error in my preconception of the definition of the term "rise time", and I subsequently admitted as much. No insult was intended. Yes, things can get heated here once in a while. You came here with your mystery. Now you want to insist that you alone have solved it. OK. I read that your preamplifier uses no output coupling capcitor; instead, it uses a servo to balance out any DC offset in its output. So your preamplifier could in theory emit DC, IF and only if its servo corrector is not operating rapidly enough to prevent any DC offset in its output. But even then, the error in cancelling DC would likely be in the low mV range, perhaps not enough to move your woofer so obviously.  (I say this because I use an Atma=sphere MP1 preamplifier that also uses a servo to cancel DC, and I have measured the error at 2mV, max.) I don’t know what amplifier you are using. If your amplifier uses a coupling capacitor at any point in its circuitry, then the amplifier cannot pass DC to your speaker, even the low level that might theoretically get past your preamplifier. Those are just facts. Not insults. I am only interested in getting the facts straight, because if you write something here that is just not possible based on facts, then some other reader may be misled. I operate on the assumption we are all here to learn.

I’m still trying to wrap my head around this

DC into your woofer might burn up the voice coil but won’t move the diaphragm.

It’s not just this or just one board contributor. I find a subset of people in the Analog section of the board who are terse, unhelpful and impolite if not outright rude and insulting. What could be more unhelpful than to present, as a fact, something that simply false. There are other sections of this forum that are genuinely helpful.

I don’t know about anyone else but I feel like I stuck my hand in a bear trap by posting here. I saw something weird and shared it. I thought maybe there was a quick explanation (also, it was kind of funny). The act of posting doesn’t automatically mean I’m fair game for anyone’s ego trip. It also doesn’t mean I’m an ignorant newbie to be kicked around. For that matter neither is anyone else.

I pity the kid who is fighting with their first turntable and asks a question here. Approaching others with a little kindness and empathy as well as minding one’s manners would go a long way to improving this section of the forum. Fact checking before posting should be a no brainer.

Sorry. I’m wrong when I wrote DC has no rise time. I still doubt DC is moving your woofer at whatever low frequency it’s moving. And constant DC of one polarity will burn out a voice coil. If it’s rapidly changing polarity by 180 degrees perhaps not.

@lewm I don't know why you feel compelled to "correct" me.

DC will move and hold a driver. 

Example:

Show me or describe the wave form. You could be describing a square wave, which is complex AC. DC seen on a scope is a flat line with respect to time. The vertical position of that line will depend upon magnitude. DC into your woofer might burn up the voice coil but won’t move the diaphragm. Whatever the source is that’s moving your woofer it is an AC signal doing the work..

Which definition? What do you call the period of time in which a DC signal increases in amplitude, repeatedly and predictably, after which it decreases in amplitude repeatedly and predictably? 
 

DC has no "rise time", by definition. 

Kudos to @dadawada 

I think the reason the rumble filter doesn’t stop it is that it’s DC with a slow rise time. The o-scope looks hilarious.

It’s static. I converted back to balanced operation and wet cleaned a few LP’s. Problem gone. I have an Ionizing fan on order and we’ll see how that works.

The idea that the ES charge is concentrated at one area on an LP or on the mat is contrary to data collected by Shure Corporation, when they studied ES charge in vinyl reproduction, albeit many years ago; they suggested that charge distributes evenly across an LP surface.  However, I could perceive that there might be some assymmetry to charge distribution due to fingerprints or other oily or watery deposits on the LP surface.  So perhaps the data you cite would contradict their earlier findings.  I will take a look. 

How does a static charge and electric field manifest itself in the signal?

And we still have not had an answer as to whether the 18Hz high pass filter on the preamp was engaged during all of these investigations.  If it was engaged, then I would expect there to be little to no woofer pumping when the platter is spun at speeds below 18Hz.  Yet I thought the OP reported he can spin the platter by hand at speeds well below 33 rpm, and still visualize the phenomenon.

If it was say the magnetic field from a Hall effect sensor or the motor, then as long as the thing is localised to a small fraction of a rotation, then it will appear like >18Hz.

In XLR configuration, positive attaches to Pin 2, negative to Pin 3, Pin 1 is vacant and the shield is attached to the shell. The shield is floated at the TT end.

^As you have said^… that is pretty much the main difference, and hence why I suggested that you could try attaching Pin-1.

@ejb14

The cable set is not a coaxial design.

The cables are the same in both RCA and XLR configurations. The cable itself is a star quad core with double bare copper shielding.

With RCA attached, the positive signal is using, say the 12 and 6 o’clock wires. The negative signal is using the 3 and 9 o’clock wires. The shield floats at the TT end and is joined to the negative wires at the RCA collar joint. The positive is joined at the pin.

In XLR configuration, positive attaches to Pin 2, negative to Pin 3, Pin 1 is vacant and the shield is attached to the shell. The shield is floated at the TT end.

The tonearm ground handled by the external ground wire in both cases.

@lewm  - on the high pass filter, I asked the OP about that in an earlier post and he did say it was engaged in all his tests - the response was:

"The weird thing is that the hi pass filter works, I have some real nasty LP’s that rumble and the filter knocks it out. So your guess is as good as mine. Also the pumping was worse with the filter off- real audible bottoming out stuff."

Also, in the video you can see it is on - the PPA-2 shows that on the front panel (4th LED from the left).

I watched the video again in the beginning, and the woofer excursions are not uniform - two large excursions (I think), followed by a higher speed flutter of smaller excursions before a very brief rest and then it starts up again - the whole sequence at what appears to be once per revolution. However, this might not mean the static is unevenly distributed on the surface - it could be this is just how the PPA-2 or the 851A integrated reacts to what seems like input overload.

I still wonder if that with the XLR connections, and the PPA-2’s different grounding scheme separating tonearm and chassis ground, that the static has no where to go but through the signal path and get amplified. With the RCA connection, the static can get to chassis ground via the RCA shields (assuming those are connected to chassis ground - they usually are) and then can dissipate through the IEC outlet and not get amplification.

The idea that the ES charge is concentrated at one area on an LP or on the mat is contrary to data collected by Shure Corporation, when they studied ES charge in vinyl reproduction, albeit many years ago; they suggested that charge distributes evenly across an LP surface.  However, I could perceive that there might be some assymmetry to charge distribution due to fingerprints or other oily or watery deposits on the LP surface.  So perhaps the data you cite would contradict their earlier findings.  I will take a look. 

And we still have not had an answer as to whether the 18Hz high pass filter on the preamp was engaged during all of these investigations.  If it was engaged, then I would expect there to be little to no woofer pumping when the platter is spun at speeds below 18Hz.  Yet I thought the OP reported he can spin the platter by hand at speeds well below 33 rpm, and still visualize the phenomenon.

@lewm If you look up VinylAttack on YT, you will see he has done a number of tests dealing with measuring static build up on vinyl using anti-static brushes and Zerostat guns. The videos may help to understand what is going on.

If I may quote myself:

That charge won’t universally distribute evenly across the record, as the vinyl itself is an insulator. Something you are doing is leaving a charge, and that charge is concentrated (possibly) at the last place you touched the record. That concentrated, persistent static charge is inducing a periodic, low-frequency signal via your cartridge.

Here's a video of a demonstration that clearly shows this concept in action.

How do you explain the periodicity? Wouldn’t the mat be uniformly charged? 

@mitchellco , I'm the one that suggested the dryer sheet. It was clear to me that the rubber mat was holding a static charge. The only question was how to dissipate it. I just pulled the dryer sheet out as one of many possible solutions. I'm glad it worked out.

Is it possible this has something to do with the fact that the Elac PPA-2 is a somewhat different phono stage in that it has separate chassis ground and signal ground pins. The PPA-2 floats signal ground above chassis ground according to Peter Madnick in the youtube video he put out describing the PPA-2. 

@mitchellcp , I know you posted this earlier, but it bears repeating - from the manual: "However, you must be careful that the shell of the XLR is not connected directly to the ground line within the XLR connector. They SHOULD be independent. The shell is the external shield of the cable and connector, and should be the CHASSIS connection."

This implies to me that with a singled ended RCA connection, inside the PPA-2, Mr Madnick connects the RCA shields (which in the single ended configuration are connected to the negative pins on the cartridge) to the chassis ground, and then has a path to the IEC connector and to ground at your outlet - thus the static generated signal has a place to go that is not in the signal path. This is easily verified with a DMM on connectivity mode - just put one probe on an RCA shield and the other probe on the ground pin on the IEC. I am almost certain it will beep.

@mitchellcp

Your problem is definitely one of the most baffling I’ve ever read about! Wow. I’m struggling with a different but also baffling problem in my 2nd system - exceedingly loud occasional POP noises during playback - and it’s with records that don’t do that in my main system, and I’ve also swapped out just about every component trying to isolate or affect the behavior, and tried all kinds of static control measures, and power conditioning, to no avail yet. I don’t want to keep subjecting my tweeters to this crap.

It’s down to either the cartridge somehow being at fault, or the fact that my main rig’s VAC phono stage and SUT (since you mentioned SUT) is somehow protecting or not exacerbating these kinds of issues. I’ve long used a SUT in my main rig and perhaps it has some positive protective benefits beyond just the sound quality (which I also like - it adds warmth and body). Surface noise and pops have always been kept to a very reasonable minimum level in the main rig. An excellent analog experience has long been easy peasy, in that rig. I just bought the VAC phono and SUT over to the 2nd system; fingers crossed.

My issue has driven me bonkers, and I’m sure yours has done so as well. Hope we make some headway soon!

Pixies for sure.

since no hypothesis offered so far really holds water, who is to say that a step up transformer would not eliminate the problem? But do you wish to continue to operate in balanced mode? I thought you got rid of the problem simply by converting to single ended mode. If you are happy with single ended mode, why think about a step up transformer.?

Is it really the case that you’ve been using a hi-pass filter operating above 18Hz in all cases? You earlier stated that if you move the platter manually at sub 33 rpm, presumably at and below 18 rpm speeds, the pumping occurs with frequency proportional to platter manipulation. That seems impossible so I must misunderstand.

I’m thinking an SUT might be a solution. Any thoughts on that?

@holmz 

This makes zero sense to me…

Agreed

The cart is generally a thing that generates a current, and the electrical field would seem to be difficult to get into a twisted set of differential wires.

And to get enough charge on the LP to merry-go-round in a pile of electrons, and generate a magnetic field, would be difficult.

And to do it with Every LP you tried? 
 

Yes
 

And even a just with a mat alone?

Yes

And never without a mat or LP?

Never, no movement at all

I think I am back to the @lewm idea of oscillation in the phono stage. That would either need some different loading, or to block the low freq with a high pass capacitor in-line.

The PPA-2 has an 18hz Hi Pass filter which has been engaged for every experiment . It apparently does have any effect on a signal that operates as a sloping sine wave in the cycles per minute domain. I say that as a guess.

@noromance I also used an AQ anti static brush while touching the tonearm.

@bato65 I just moved into this house so it’s one thing at a time. If I were to add a central humidifier I would lose the experience of dry cracked skin, sinus trouble and static electricity discharges that leave scorch marks on my dog.

Gremlins.
Is the turntable spindle - bearing assembly - bearing housing (somehow) connected to the ground? If not, could you try to conjure those gremlins and lead them away by connecting the bearing housing to the chassis of your amp? 
I had problems with static buildup, especially in the winter months. My TT is a big chunk of Delrin... If I didn't touch the LP first then lower the cartridge on it, there would be audible (and scary!) discharge. On the end I approached the problem in the same way as I did the power surge: if it hurts my system, it hurts every other device in the house. So, I bought a new and much better humidifier (at the furnace, whole house). Humidistat is set at 30% in the summer and 45% in the winter - and tweaked from there. Someone already commented that humidity in your house is low. Even 5% makes a noticeable difference. And yes, there is that damn "sweet spot" even with that...

OP, You also said that the pumping frequency of the cone was directly proportional to the hand-powered rotation of the platter. Surly the static build-up would be caused by rotation speed? When you moved the platter by hand, wouldn't the static be grounded by your touch?

…
Next up, Static Electricity. I forget who (sorry) but it was suggested that wiping a record with a dryer sheet might affect the pumping. I observed the pumping with only the mat  to get a visual baseline, then applied the dryer sheet while the platter was spinning. The amplitude of the woofer excursions diminished visibly while I was wiping the mat, I’d say by 80 to 90 percent.

It would appear that the correct answer is, levels of static electricity not enough to arc but enough to influence the Hana ML while operating in balanced mode

This makes zero sense to me…

The cart is generally a thing that generates a current, and the electrical field would seem to be difficult to get into a twisted set of differential wires.

And to get enough charge on the LP to merry-go-round in a pile of electrons, and generate a magnetic field, would be difficult.

And to do it with Every LP you tried?
And even a just with a mat alone?
And never without a mat or LP?

I think I am back to the @lewm idea of oscillation in the phono stage. That would either need some different loading, or to block the low freq with a high pass capacitor in-line. The later could ameliorate the problem, but it does not illuminate the mechanism.

@ejb14 

nope- single end doesn’t do it at all under any circumstance 

@mitchellcp - thank you very much for reporting back on this. I admit to rubbing a record on my head until my hair stood on end trying to reproduce this when static was suggested, but to no avail - though I only have single ended connections. The static must still be there when in single ended mode, so I wonder why it does not create the issue? I know that you get more gain with the XLR, but those woofer excursions in the video were quite large. I would expect if that was it, you would just have smaller woofer excursions with single ended connections.