I finally get it!

I've had two VPI Tables (Traveler V2 and Super Prime Scout), and while there's a lot to like about them, I also found VPI's dismissive attitude to manufacturing differences (P2S being one, regardless of actual importance, or other one-off changes during a model's lifecycle etc) and overall tolerances too high to take them seriously. Sure you can often bring their tables' back into/near spec once you set them up, but then again why do they ship so many tables out of spec??

Once I had checked out Rega, and now using an SL 1200GR, I'll never buy another VPI again.

..one thing to add.  When setting the cartridge in the right spot on arc protractors with slotted attachment head, you must be able to make sure the cartridge is square to the arc (or as best as it's possible) or the alignment will be off. That's the reason I use the MINT, it makes this adjustment doable if the instructions are closely followed.

You can always widen the hole a little so you can move the arm in the right direction then tighten it down.

Thanks @boxer12

A arc protractor is free.
As downloaded SW and you put in your specific TT S2P distance.
And you chose what mathematical equation that you want (Löfgren A/B, Bergwall or ..)
Print it out, check distance of the printed result to ensure it is in scale.
Done.

As for azimuth I were one of them that obsessed to get my setup as good as possible. After reading people setting up with special test/calibration records. And with special equipment (fozgometer) or computer software. I also used digital oscilloscope and so on.
Read people that had many different pressings of Denon calibration records + other brands of calibration records. And they come to the conclusion that every single calibration record measure slightly different... And remember supposedly when making a calibration record they hopefully make all the angels setup on the cutting lathe as good as possible.. and we end up with variance anyway..

So should we set up perfectly against one calibration record? What is then the result.. .. that we only have a perfect setup on THAT record that mimics just that particular angle that the cutting head had when it cut just precisely THAT laquer..

So the lesson was azimuth vary from album to album. And if we suppose that the cartridge manufacturer has done as good job that they can do. Then it is just to put your cartridge for azimuth as horizontal as possible. And in a average between albums it will be the best.
(If it is not damage/faulty in any way)

Right. I wish more would realize this. Not as much for their own sake. Anyone wants to spend more money on protractors than stuff that actually makes music, and more time obsessing and fussing over microns when the dang thing ain't within millimeters most of the time anyway, that's all fine with me. To each their own. 

But unfortunately new people come along and see this and conclude playing records means having to do all this crap. Happens all the time. Then they either sit there looking at the ten grand rig waiting to pay some dude to come set it up, or decide its just not worth the hassle. Which is a shame. Because its not a hassle. Its easy. But who is gonna believe that when the guys who want to make everything just as hard as it can possibly be are sucking up all the oxygen in the room?

oldears has got it right. A 1 mm difference in pivot point can easily be accounted for by any protractor with the exception of the expensive "arc" ones that are adjusted to the theoretical distance rather than the actual distance.

Theoretics aside, I have always believed that the adjustments for horizontal tracing angles (for which there is no universally accepted standard--there are many and all are compromises) are obsessed over.  Not to mention the hundreds of dollars spent on protractors that give the same result as a $20 one.  Proof of this, I suggest, is found in the success of the Viv Lab Rigid Tonearm, a short arm with no offest.  Said to sound great.  Tube units measure worse and sound better.  Same with LPs and digital, same with belt drive over most DD.  The only test is your ears.

More important cartridge adjustments IMO are SRA (depending upon stylus shape) and especially azimuth.

Exactly that I am trying to say.
Excellent idea to move the pivot point instead. 
So the spindle to pivot length is nothing to OCD about.

The just make sure that we can hit both of the points on a arc protractor without moving the protractor or turn the platter.

(If you do it by moving the pivot point or sliding the cartridge back and forth in the head shell just don't matter.)

And we are done with a alignment.

First and foremost, every time I see Phoenixengineering participate on this Board I smile. He is a great all-around guy and has a wealth of useful knowledge. 
Now that aside, as someone who gave up on VPI decks (three of them) and went to vintage decks on custom plinths and Reed 3P arms, I have learned from personal experience that P-S is not a demanding spec if you have a typical headshell that allows the cartridge to slide back and forth. I have learned from mounting my own arms that a tonearm's manufacturer's specified P-S may not allow for all modern cartridges to come into optimum alignment. You may argue that this is the fault of the tonearm manufacturer but such is not necessarily the case-often it is due to the cartridge manufacturer having an unusual stylus to cartridge body mount configuration. 
Case in point would be my current VdH Crimson Strad. When I mounted my 10.5 Reed 3P to the spec'd P-S, I could not move the cartridge far enough forward to get to the Lof B on my Feickert alignment grid. Remounting the arm a few mm's further away from the spec'd P-S allowed me to the to that point. 
Brian Walsh of ttsetup.com confirmed that what I had done is the only approach and that it does not, in any way, compromise performance-he was able to accomplish optimum alignment with his very sophisticated software based tools. 
So imho HW is correct that being a mm or two or even three is not a problem if the stylus can get to the desired point given your alignment type/choice. To put it slightly differently, the stylus does not know or care about the P-S distance. P-S serves as a range within which most cartridges can be optimally aligned within the slots. I have said this before and will say it again-the SME approach to P-S proves my point: no slots and instead the P-S is changed for each cartridge using their ingenious pivot point sled. 

Maybe I am naive or maybe someone could explain to me what the SONIC difference is between -1mm and +1mm S2P difference?

If there is enough space/play in length of the slotted head shell cart mount hole.
So you are able to get desired overhang and hit you preferred alignment type.

Then there should not be any SONICALLY difference between those two S2P distances.

It only become a problem if you can not reach the desired points for your arch protractor/overhang. So as I see it the slotted holes in the head shell allows some tolerance in pivot to spindle distance.

And we then fine tune it IF we use a ARC protractor that fix the overhang!

But yes you loose out if you use a tool that set the overhang by other suboptimal techniques.

As everyone understands now that a arc protractor has yet here another benefit when it adjust the overhang and in the process fixes any intolerances that just that specific TT and tonarm combination has! 

Every TT has a unique S2P distance because of their is always a slight mounting tolerance of ± X.XX mm. 

So please use a arc protractor and this P2S issue is not any issue anymore if you can adjust in the slotted holes in the head shell..

IME that is a serious oversite. High end analog is not at all forgiving to issues like this. Glad you got it worked out Slaw. 

I have a MINT alignment tool which is exacting like VPI's.....

@phoenixengnr From the table on the turntablebasics website,for a 230 mm EL the optimum OH is 18.14, and the angle is 24.083 deg:for a 229 mm EL the optimum OH is 18,05 and the angle is 23.972 deg.This kind of difference is hard to measure, thus not a drama.
 

The 1 mm error in 230 mm is 0.4%. I can't name manufacturers, but I recall both Fremer and Dudley mentioning this kind of error more than once.

Please read the references.

@bdp24 ,

I hear you brother 

I became a believer years ago, when I first made a wire loom for my ET arm. It was a revalation.

@oldears,

Drama? That's your term, out of nowhere.

A 1mm error in effective length implies a 0.1mm difference in overhang and a 0.1 deg difference in cartridge alignment. This should not be a drama. Read the articles.

@olddears

Where are you coming up with your numbers? A 1 mm difference in effective length (or S2P distance) will create a 1 mm difference in overhang and 0.87° tracking error at the null points and 1.47° tracking error between the nulls. Not huge, but an order of magnitude higher than you are quoting and completely unnecessary.

What other mfrs are as sloppy about this as VPI?

A 1mm error in effective length implies a 0.1mm difference in overhang and a 0.1 deg difference in cartridge alignment. This should not be a drama. Read the articles.

Well, in my case, I had to take in account the two points of geometry and the manufacturer' lack of geometry.

I would guess a lot of manufacturers are no more accurate than VPI. 
Please read the reference to see the consequence of errors of 0,5mm and 0.5 deg offset. I am not being critical of anyone, just trying to provide accurate info. Basically if you are aligned at the 2 chosen points for a given geometry you have done everything you can for the cards you have been delt.

Thanks @oldears ,..

You do realize my issue was with the manufacturer.?

Few audiophiles are going to bother to look because their stuff is too cheap. But the info on their site is correct. Their 20 buck protractor is very good and precise, and can be ordered in 2 spindle sizes and with Baerwald or Loftgren B alignment. No need to spend $250.
The definitive reference on tonearm alignment was an article in Stereophile by Keith Howard. It can be found by searching for: stereophile optomizing tonearm geometry. Read and learn.

@oldears ,

Always willing to learn.

@slaw Go to turntablebasics.com and look at alignment tools. They have a lot of good info about tonearm alignment on their site which may be helpful to you.

@bdp24  got an extra Decca laying around ????

@tooblue ,

It was 2 mm short.

Many people including Mat say this isn't an issue. I say they are wrong. My ears confirm this. I read a while back that Mat said he's made a new jig to address this.

@slaw , that is very good to hear, that good results can be had with the noted discrepancy in the pivot to spindle distance not being as advertised. The issues with both my tables is that the stated spindle to pivot distance is one mm short. Was wondering where yours was when you sent it back to VPI to have them send it back one mm long?

Just curious to the swapping to an Origin Live arm or any other arm addresses the pivot to spindle distance being off, would you not have to have that correct before you install any arm? I personally do not have an issue with the VPI unipivots and run a 9 and the 10 3D in two different systems and suffer the same problem with both on the issue of spindle to pivot being off on their given tables. 

@bdp24 ,

Thanks for the offer Eric. I'm currently having my Funk Firm arm upgraded with AN wire straight through to eliminate the DIN connection. 

Hi all. I finally went through my set-up yesterday allowing for the factory malfunction and have to say, everything is sounding better than ever.
I think this is important for VPI owners to understand.

The Spindle to pivot distance is specific to the arm being used. What you complain of is typical of VPI's tolerances. You would be best served by replacing that arm with something like an Origin Live arm. The platter and bearing are fine (VPI  does not make them.) Isolation of the plinth is not good but you can deal with that by putting a sprung platform under it. 
VPIs best product is their DD table with a gimbal bearing Fat Boy.  

slaw-
VPI has their metal work done by MDI, a very competent machine shop in NJ, so I don't think it is machining tolerances.  VPI assembles the parts, made by other companies for them, so it may be an assembly error.

From what I can tell, part of the problem is HW never put much importance on S2P measurements:

https://www.audioasylum.com/cgi/t.mpl?f=vinyl&m=1122027


This is a strange position to take for a turntable mfr, but  it might explain a lot.  IMHO, HW doesn't really understand tonearm geometry.  He has touted a 14" tonearm with no offset and claims it has no skating force and two null points; both assertions are incorrect (the math to prove this is trivial).  He posted that he discovered the benefits of no headshell offset by twisting the cartridge on an overhung tonearm with offset until the cantilever was aligned with the arm tube and the sound was "jaw-dropping".  I think the only thing that would be jaw-dropping would be the distortion as the tracking error would be ~17° and the distortion would be approaching 20%.

I’ve owned four VPI tables (two currently), but all without VPI arms. I’ve had a few uni-pivots and a Well Tempered, but just don’t like their "feel". The VPI platter spindle/bearing is machined to pretty high tolerances (no play/slop), as are their really good platters. Steve, I have a spare Zeta if you want to try a classic. ;-)