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

This one is a pickle, to be sure.

I wonder if this table has a signal cutout mechanism that detects when a record is on on or off the platter and shorts the output when there is nothing on there? My Dual 701 has a signal cut mechanism, but used differently - it cuts the signal when lifting at the end of a record or when auto-starting. The point is that some turntable manufacturers have thought to prevent outputs in certain conditions and Yamaha has done this with some of their tables. I don't know if they did it for this one. What are the two holes in the platter for I wonder?

You could test this without changing the interconnect plugs. Just put your stylus over the spinning platter and use a stylus brush to lightly touch the stylus (like you would be cleaning it) and see if it makes any noise in your speakers. Then do the same with the platter mat and record off and see it still makes noise when brushed. 

A few questions;

1. Isn’t woofer pumping caused by infrasonic frequencies (below 20hz)? A John Atkinson quote from 2009 Stereophile seems to support this, though he was referring to record warps in that quote;

https://www.stereophile.com/content/bass-cone-flap-1

2. The PPA-2 has a rumble filter and I believe that I saw it turned on when the woofer pumping is occurring - doesn’t a rumble filter filter out these frequencies precisely for this reason - to prevent large woofer excursions? If so, it would seem the rumble filter is not working on this phono stage - you may want to look into a warranty repair if we can assume the woofer pumping is being caused by infrasonic frequency.

3. Not sure how static would cause the cartridge to output signal in the infrasonic range. Even so, the Funk Firm mat claims to be static free, yet with just that mat on the platter still exposed this issue; so if not static, then what?

Yeah, @mitchellcp you said this in an earlier post - "Woofer pumping is tied to rotation speed, the pumping is faster at 45 than 33 also spinning the platter by hand will excite the woofers."

When you were spinning by hand, was the turntable power on?

Also, when you tried 33 and 45 did you turn anything off in between? I ask because @lewm talked about turning on and off equipment can yield different results with the oscillation idea.

Not sure this below is representative, but it is interesting:

I managed to reproduce woofer pumping, with my old Dual 701/V15III (direct drive) unplugged from wall power, the platter on or off, and just having the stylus near the motor housing and spinning the housing or platter by hand. More pronounced with the platter off. I can go real slow and get real slow woofer pumping, or faster and get fast woofer pumping. Move the stylus further away and no pumping. I had to turn the gain almost to full to see anything though; increasing the gain on the phono stage increased the extension of the pumping (makes sense).

I also reproduced this, but it was much more mild woofer movement, with my old Technics SL-D20 (also direct drive), again unplugged from wall power and just spinning the platter by hand.

@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. 

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.

@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.