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

@byang12  I’m confused, could you restate that?

It’s kind of reproduced except mine needs a record or synthetic mat or both.

So it pumps with a record and not a mat, but no pumping with just the platter?

 @byang12  I’m confused, could you restate that

There is pretty much electrical field and magnetic field.

I am having a hard time with an electrical field that is at 1/2 RPM… and a magnetic field should not be affected with just a piece of vinyl on top of the alloy platter.

It is either coming out of the cart itself, or it needs to be tied to the ground wire, like making some differential voltage between the ground and the cart, which is tied to the platter phase.
But those mechanisms should not be tied to rely on a mat or piece of vinyl.

I could imagine Lewm’s idea of electrical being tied into the electrical side.
@mitchellcp previously I think that you mentioned that there NO ground wire running to the electronics… and the PIn-1 is not tied to ground.

I am wondering if pin-1 should be tied to the ground at the TT end.

@holmz 

The wiring rundown is here.

Wiring for the tonearm to the preamp was as follows:

• Pin 1- no connection
• Pin 2- + positive
• Pin 3- - negative
• Shell ground- cable shield

Why was it wired like that? I agree the typical connection is pin 1 for the shield. See excerpt from the Elac PPA-2 Manual:

"Typically a balanced connection will be more immune to hum, so it would be the preferred connection. However, you must be careful that the shell of the XLR is not connected directly to the ground line within the XLR connector ( That sentence is a little confusing but I take it to mean that the shell of the XLR should not be connected to pin 1). They SHOULD be independent. The shell is the external shield of the cable and connector, and should be the CHASSIS connection. The ground wire within the XLR is twisted with the (+) and (-) balanced and should be the signal or tonearm ground. This can all be confirmed with an Ohm meter. "

The PPA-2 has two ground lugs, one for tone arm ground (labeled ground) and one for chassis ground (labeled chassis). Since there is no chassis ground on the GT2000, that lug remains unused. The tonearm ground is connected via the other ground lug.

The cable shield is NOT connected at the TT end, but is connected via XLR shell to the chassis ground.

 

I’m still thinking you are putting a static charge on your records. 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.

I also still think the conversion from balanced to single ended isn’t what resolved your issue. You created a better ground path to dissipate the static charge. I’d bet that if you ran a very thin wire from your head shell to ground you would have resolved the issue as well.

BTW, I’m running balanced from cartridge to speakers (and have been for 17 years). Soundsmith Aida -> OL Enterprise -> AudioQuest Leopard (balanced) -> Ayre P-5xe (balanced) -> AudioQuest Colorado (XLR) -> Ayre AX-5/20 (balanced).

And I can tell a difference if my table bearing is properly grounded or not, particularly on dry days. 

You have a relative humidity of 25%?!?!

Way too dry.

40% to 50% should be a your target. 

your statement:

Wiring for the tonearm to the preamp was as follows:

• Pin 1- no connection
• Pin 2- + positive
• Pin 3- - negative
• Shell ground- cable shield

is very very confusing.

This tonearm is for custom mono cartridge? For stereo cartridges, 4 color coded pins (same four pins from arm) are:

positive 1

negative 1

positive 2

negative 2

There is no ground pin for cartridge.

My experience is that ground loop hum/electro-magnetic noise has nothing to do with RCA or XLR plugs if ground wire was connected properly.

remember, Tesla proved a long long time ago that electro-magnetic energy could be transform from source (turn table/cartridge) to receiver (phono stage inputs) if no ground shelling to short the energy.

Actually, this phenomenon states a fundamental fact:  electro-magnetic energy broadcasting as waves/Strings not as particles. So the great Einstein could be wrong right here. 

@byang12 The pin 1 ground to tonearm is the only missing piece of the puzzle, however since the tonearm is already grounded to the phono preamp via the external ground wire, I felt that sending the tonearm ground down the left cable, the right cable and the external wire was not a great idea. My assumption at the time was that the tonearm ground lug was most likely connected at the same circuit point as the two pin 1 connections. 

We'll find out latter this week. 

Just to clarify one point, the TT is grounded to the preamp. The question being is it the correct point?

@nrenter I will be addressing the static issue as well, later this week.

In connecting a cartridge in balanced mode, to a balanced phono stage, ground is left to "float".  As you know, the cartridge has no ground connection, per se, except for a very few older designs, like (I think) old Decca cartridges, and those cannot be hooked up for balanced drive. The shield on the phono cable itself, if there is one, can be attached to phono stage ground lug, but I have three TTs operating in fully balanced mode, and in no case has it been necessary to ground anything to anything. I don't see any problem with Mitchell's wiring scheme, certainly not one that can account for the phenomenon. And it's not confusing.

Someone else very early on mentioned the Hall Sensor, which is very likely used in the drive system of the Yamaha, because it has a DC coreless motor.  On my Kenwood L07D, also coreless and also DC, the Hall Sensor is fixed to the plinth surface under the platter, but there must also be a signalling device built on the underside of the platter itself that rotates with the platter and triggers the sensor if there is a speed error.  It seems possible that in balanced mode the phono stage is picking up a signal from the cartridge, as the Hall component that is fastened to the platter rotates under the cartridge. This is causing an impulse from the cartridge to push the woofer in concert with TT speed.  But why this happens only with platter mat and LP in place, I do not know.

One idea why the problem only occurs in balanced and not in SE mode might be that in the latter case, both channels ARE connected to audio ground, so maybe the signal never gets to be amplified to drive the woofers.  It would be interesting to hook the output to a 'scope and see if one can detect the spurious signal on hot or ground in SE mode.

In connecting a cartridge in balanced mode, to a balanced phono stage, ground is left to "float".  As you know, the cartridge has no ground connection, per se, except for a very few older designs, like (I think) old Decca cartridges, and those cannot be hooked up for balanced drive. The shield on the phono cable itself, if there is one, can be attached to phono stage ground lug, but I have three TTs operating in fully balanced mode, and in no case has it been necessary to ground anything to anything. I don't see any problem with Mitchell's wiring scheme, certainly not one that can account for the phenomenon. And it's not confusing.

I don’t see a problem either, but to attach the shield to ground, seems worth taking a lark on trying?

Someone else very early on mentioned the Hall Sensor, which is very likely used in the drive system of the Yamaha, because it has a DC coreless motor.  On my Kenwood L07D, also coreless and also DC, the Hall Sensor is fixed to the plinth surface under the platter, but there must also be a signalling device built on the underside of the platter itself that rotates with the platter and triggers the sensor if there is a speed error.  It seems possible that in balanced mode the phono stage is picking up a signal from the cartridge, as the Hall component that is fastened to the platter rotates under the cartridge. This is causing an impulse from the cartridge to push the woofer in concert with TT speed.  But why this happens only with platter mat and LP in place, I do not know.

Yep -it wakes little sense how the mat and LP could contribute

One idea why the problem only occurs in balanced and not in SE mode might be that in the latter case, both channels ARE connected to audio ground, so maybe the signal never gets to be amplified to drive the woofers.  It would be interesting to hook the output to a 'scope and see if one can detect the spurious signal on hot or ground in SE mode

If the signal was sneaking in on the ground, then the SE is tying the phono stage to the TT. And the pin-1 being disconnected, is not tying the XLR to ground.
But this also would suggest that the XLR at the TT side may not be wired as push/pull and maybe has the out of phase side tied to ground?

sound like your cartridge/arm wiring is specific for SE output.

the correct wiring for balanced wiring supposely take (+) and (-) pins to pin 2 and ping 3 in XLR connector. if you want to use external grounding wire between TT and phono stage, leave TT side pin 1 of XLR connector idle (floating). Otherwise, connect TT ground to pin1 of the XLR connectors. 

Above balanced wiring assumes that on Phono stage side the pin 2/3 is connection to positive/negative side of balanced input (such as step up transformer primary), would not work for SE inputs (negative grounded).

"If the signal was sneaking in on the ground, then the SE is tying the phono stage to the TT. And the pin-1 being disconnected, is not tying the XLR to ground.
But this also would suggest that the XLR at the TT side may not be wired as push/pull and maybe has the out of phase side tied to ground?"

You lost me there, but I am not suggesting or even thinking that the signal is coming in on the ground connection. Quite the contrary, the balanced connection is floated (not attached to audio ground), and the phenomenon only occurred in balanced mode.

I ended up with a snow day so I assembled two XLR to RCA adapters. I also wired a conductor attached to pin 1 in each XLR that exits at the connector base. Think XLR with an external ground wire. I made a junction for the two ground wires ending in a single wire.

So let’s dive in:

Woofer Pumping in balanced mode is present and unaffected by the presence of a pin 1 tonearm ground connection. I tried first with the XLR ground extension attached at the preamp tonearm ground lug along with the conventional tonearm ground wire and second with the XLR ground and tonearm ground attached to each other but not attached to the preamp tonearm ground lug. Neither arrangement made the slightest difference.

It would appear the pin1 theory is exploded, which is sad because the solution would have been as simple as a reconfigured cable set.

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 may be the first in AudioGon history - a thread with a resolution! Good stuff!

That’s actually pretty funny 

@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. 

@ejb14 

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

…
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.

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?

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...

@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.

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

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.

@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!

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.

@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.

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

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.

@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.

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  - 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.

@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.

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.

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.

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.

Kudos to @dadawada 

DC has no "rise time", by definition. 

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? 
 

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..

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

DC will move and hold a driver. 

Example:

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.

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.

"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.

Would you like a lollipop to make you feel better?
 

My point

Two lollipops then.

"No insult was intended."  MY point.

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.

… 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.