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Sub Sonics and woofer pumping

I have a VPI prime on bear claws sitting on a maple base. Floor is concrete. I use a Nagaoka MP500 cart with going to an ARC PH3se phono pre, then to a Herron 1A preamp. Amp is an ARC Classic 60. Speakers are Thiel CS 2.4’s. 
I get pretty aggressive woofer pumping with vinyl. 
I’ve lubed my bearings on the table.

my alignment is spot on. 
Tracking force at the upper limits of cart. 
I’ve added the 2nd pivot point to the 3D arm. 
I’ve even switched out the counter wt to a much heavier unit and added a comparable head shell weight to change the total mass of arm. To no avail. 
None of these things have had any effect in reducing the pumping. 
I REALLY don’t want to use a rumble filter. 
I’m left with the conclusion that the cart may not be a match for the arm, even after adding all the extra mass. 

Any thoughts or solutions. 
last_lemming
mijostyn's avatar
mijostyn
8,570 posts
 
Last_lemming, are you saying this occurs with more than one record??
the lead in grooves seem to be the noisiest park of the record. If this is just one record you have either a warp or a low frequency pulse at one point on the record. No big deal. If it is happening with every record you have a much more serious problem with the bearing or platter. The Cartridge is doing what it is supposed to do. If you are worried about the tonearms resonance frequency get a test record and check where it is. Very easy to do. 
big_greg
6,716 posts
 
You have two systems.  Have you tried the turntable in the other system?  Same issue there?  If not, I think @slaw may have pointed out what the issue is - placement.
last_lemming OP
639 posts
 
It happens with every record to one degree or another. On the quite passages (lead in groove, etc). That’s why I don’t think it’s a resonant thing. If there is no music how could resonance contribute that much to the pumping.  I suppose the lead in groove could have low freq vibration. 
I will try and do a thorough inspection of platter bearing and arm pivot point. 
You know i do use the 2nd pivot point modification- I wonder if that could be causing the issues?  That’s easy enough check, I’ll just disengage it. 
larryrs
132 posts
 
Given what you’ve said about the rumble being worst in the lead in groove it would be worthwhile to try a periphery ring. I use one and it is very beneficial in terms of vertical movement of the record. 
big_greg
6,716 posts
 
I recently added the 2nd pivot point to my VPI Classic 2 and it didn't create rumble, nor have I read of any reports of that in the extensive research I did before adding it.  How hard would it be to take the turntable into the other room and see if it has the same issue or not?
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