2. analog
  3. 159441-46

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
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
6,670 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?
last_lemming OP
639 posts
 
Ok. So it’s got something to do with the cart and the tone arm. Which is weird since VPI suggests the cart. 
I have a record that has a bump in the vinyl, the pumping corresponds with the bump.  Weirdly the right channel is pumping more than the rest regardless of how the antiskate is set. 
I’d like to use the calculator on vinyl engine to check resonance, but I don’t know what values to use for the 10” 3D tone arm. 
Does anyone know what I should input to check?


More to discover