STP distance. Is it critical ?

Thank You all for the info you have provided. To make it simple, i will ensure that the STP distance is dead on BEFORE i attempt to align the cartridge (A90) with the Mint LP.
Thanks again.

Dear Smoffat: According to Baerwald ( IEC ) calculator for an effective length of: 235mm the precise STP distance is: 217.36mm and with DIN standard: 218.41.

The differences in DIN against IEC is not only with the STP value but there are differences too in the offset angle and obviously overhang.

Regards and enjoy the music,
Raul.

Forgive my ignorance Raul but, what is IEC and DIN and the difference between both.
Which should i use.
My tonearm is Graham Phantom II and Ortofon A90.

Thanks

Dear Smoffat: Are standards from International Enginnering and from Germany ( Deutch ) inner/outer most distance groove that are two values necessary for the calculations.

Your Phantom manufacturer specs seems Baerwald IEC and I assume that your Mint LP protractor too. So just follow it.

Each different set up geometry calculations made differences in the percieved system sounds. So, if we have the tools, we can test either equations with either IEC/DIN standards and through listening decide which one match our priorities.

Here you can download Baerwald/Löfgren B calculators:
http://www.enjoythemusic.com/freestuff.htm

you only need to make click with your mouse in: Donload Now ( at the bottom of the page ).

Baerwald is Löfgren A in that sheet. The original values in the calculator inputs are IEC standard, you can change to DIN standard changing the input inner most value: 60.325mm by the DIN innermost value: 57.5mm

If you only want to use the calculators with IEC standard then the only value that you have to introduce is the tonearm effective length at the calculator input, then you make click in the CALCULATOR word ( in white at the center. ) and appear at the right ( green color side ) the output parameters that you need to the set up.

It is more easy to use that my explanation.

regards and enjoy the music,
raul.

I think this is how it works....

Consider the arc of the stylus as it swings across the record surface. The proper set-up establishes two null points where the cantilever is on exact tangent to the groove, the inner and outer grooves have a small out-of-tangent angle.

Moving the pivot point of the same arm away from the platter center changes the position of the arc across the record surface. The two null points are moved closer together and the tracking angle at the inner and outer grooves is greater. Sound quality suffers at the outer grooves, but the tracking between the two null points is a little better.

Moving the pivot point of the same arm close to the platter spindle moves the null points farther apart resulting in a greater tracking angle error across the middle of the record, but coming closer to tangent on the inner and outer grooves.

In both cases of "improper" set-up, the worst-case tracking error is greater than if the arm/cart is set-up as designed. The differences in cartridge alignment points is based on the location of null points, and the location and degree of tracking errors.