VPI 2nd Pivot for 3D

"I have a couple of questions that I would think be of concern to all VPI owners: @billstevenson, You may be positioned as our best form of information on these questions?

(1) The factory off-set setting of S2P distance by 2mm on my Classic 3....is this difference on any of their other TTs? The Prime? Why is it a good thing? If it isn’t, why are we experiencing it?
(2) Is there a good reason why a designer of TTs and tonearms won’t reveal their preferred cartridge geometry method? "

 I wanted to avoid this can of worms.  I don't know if I can help clarify or just add to the confusion.  My Prime has a S2P of 261.5mm actual, vs. the specified 258mm.  I had a protractor constructed for the actual S2P to address the issue.  Matt at VPI offered to fix mine if I returned it, but in my mind as long as the actual S2P is accounted for it shouldn't matter.  Not everyone will agree with my decision, but it seems to work just fine.  I will offer conjecture that the reason why any manufacturer would not want to reveal a preferred cartridge geometry would vary depending on their priorities and overall philosophy.  Why limit applicability of their product?  How critical is the geometry issue in practical terms?  Records are imperfect anyway.  Get everything dialed in for side A only to discover that things are skewed for side B (this happens all too often).

@billstevenson. Thank you for your honest response! It is what seems like a flower in a field of weeds.

I for one want to purchase a product that I feel, after reading for years is a solid product, I can have confidence in it’s accuracy of manufacture.

"How critical is the geometry issue in practical terms"? Wow! I would think, coming from you, it would be critical? As I said previously, I want the product I paid thousands of $ for to be accurate. The inaccuracy should come only from the end user.

"I wanted to avoid this can of worms". (A can of worms.. people, did you think you’d have to deal with a "can of worms" after laying out $$$???) Let’s try to define this...

(1) Why is this an issue to start with from an American TT manufacturer that has 40 years of history?
(2) ..on my question about revealing cartridge geometry... "Why limit applicability of their product?"

Lets start with #(2). How does having the tonearm geometry of a brand new TT/arm limit the applicability of said product? If it does, is it not on the manufacturer to let their potential customer/s in on this thought prior to purchase?

"Mat at VPI offered to fix mine if I returned it...".

This implies that Bill Stevenson addressed this issue with Mat, (as a concern).

I never received this option when I spoke with Mat. If I did, I'd gladly take him up on it.

Dear @slaw : """  But the 2nd pivot mod also changes the original design concept, thereby making it (not a unipivot anymore). This is, I think, the argument Raul is making and the point I was initially referring to. """

That's it, thank's to put the " ligth " on what I wanted to explain with out to much success.

@billstevenson , only for you can think about: the VPI unipivot and the one with the 2nd pivot overall are the " same " but the dual pivot performs way better.

My starting participation in this thread through my Stringreen anser was that the dual one performs better because the 2nd pivot gives it a way better stability.

Now, that was and is my argument but you disagree telling that the unipivot has no un- stability problems ( when in reality has. ).  You posted " facts/tests " trying to prove it with no success.
So, why all the named tonearm manufacturers gone for the dual design ( changing from unipivot to dual pivot. ) and all dual pivot tonearm owners attest with out doubt the dual pivot better performance if it's not that the dual pivot has now better stability that's something the cartridge ask/shouts for it.
No pun intented, just think about.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Just another point on the 2nd pivot.  Using the Fozgometer...take your time and get it perfect...it can be done with the 2nd pivot...just screw it down or up and it stays.  Its almost impossible to do without the 2nd pivot in place.  As the  Foz needles get closer, just a small adjustment makes a very big difference. My Foz meters are nearly pegged for both left and right.  It makes a very big difference in the sound.