How much difference if the tonearm is mounted 5mm

Lewm,

I should also mention that the supplied head shell from JVC also is usable after my drilling.  But instead of the cartridge being mounted in the center of their slots, the cartridge is now mounted near the forward most location of their slots. All other brands of head shells allow the cartridges to be mounted some where around the center.  Some more forward, some more towards the rear.  But all will follow the Mint Tracker curve perfectly.
Regards,

Dear Dangcaonguyen:  """  I mounted the arm 5mm shorter than manufactor reccomedation. The result was terific.  """

IMHO what it's terrific down there are only " terrible " and high distortions not real music information.

Many years ago Löfgren makes a huge research and found out what after him was the flagship of a tonearm alingment ( you can search google for those white papers to understand the meaning/foundations of the theory. ) where vintage and today tonearms has each one tonearm specific alignment parameters.

What define those critic parameters ( overhang and offset angle ) is the tonearm pivot/bearing to spindle distance where for each PTS distance exist one and only one offset angle and overhang. Each time that STP distance change these two parameters change to aling correctly the cartridge in the tonearm.

Look, the difference between the Löfgren and Baerwald alignments with the same PTS distance is less than 0.6mm in the overhang where the offset angle stay the same in both alignments proposals. In this example the whole tracking error ( pivot tonearms. ) is different all over the LP recorded surface.

Here you are talking of 5mm!!  with out changing the offset angle!!!, so the tracking error goes up in exponential way"""" and that's what you are hearing.

Those gentlemans that gave you the advise to change the cartridge position through slots do not understand yet from where come those parameters values ( equations on the white papers. ) on overhang and offset angle.

Now, here you can read all referent to mount VPI different tonearms an you have to mount any cartridge on them through the VPI dedicated protractor and if you are in doubt then contact directly to VPI:

http://www.vinylengine.com/vpi-tonearm-geometry.shtml

and here you can read about calculators when you need a different PTS distance, overhang or offset angle:

http://www.vinylengine.com/tonearm_alignment_calculator_pro.php


or you can downland this calculator that gives you all you need to know about and know how distortions goes with changes in any tonearm/alignment parameter or alignment kind:


http://www.enjoythemusic.com/freestuff/BaerwaldLofgren88.xls


Regards and enjoy the music,
R.

I

I'm sorry Raul, but I do not listen to 'white papers' so I do not know what they sound like.  I listen to records and know what I 'hear'!  
What you state about there only being one correct number for overhang and offset angle  of any particular tone arm length is true.  But that doesn't meant that the person who came up with those numbers on my JVC templet are the correct ones!  Nor does that meant that the numbers for set-up in the tone arm in this thread are the correct numbers because they are ''only'' numbers printed on a form.  Nothing more, nothing less!  The proof is in how it traces after set-up.  Not how it measures in regards to some printed number on a form!  The arm in question was not actually measured so how do we know what its 'overhang and offset angle' should be?  You 'assume' that its length is what is stated on the templet.  You 'assume' that the dimensions stated on the templet is correct. You 'assume' that to drill this hole for the arm to mount into will be correct.  Sounds to me like you are ''assuming'' far to much and not doing enough 'actual measuring!  After drilling, it either tracks that Mint Tracker correctly, or it doesn't.  That is all, and nothing more.  If to do so, some other number had to be used to drill the mounting hole distance from the spindle for the arm, so be it.  The point is to track the curve line.  Not ''what does it measure''?
Regards,

Hi Rauliruegas,
i mounted the tonearm 5mm closer (pivot to spindle, not pivot to stylus), and used the Feickert protractor to mount the cartridge. Therefore in theory, if I understood it correctly and if we could trust the Feickert tractor, the cartridge was mounted in the right geometry figured out by the maker of the protractor. Am I right?
The only thing which is bothering me is, although the arm cartridge combnation peformed correctly, it will not get out all of its potential which the designer put onto the arm. Also, the offset angle is off at arround 20 degree make me worry for the pivot bearing.
I hope it makes sense.
Thanks,
Calvin

First of all, Hola', Raul!
Second, Dang, are you saying that after setting P2S at 207mm (which is quite short for even a 9-inch tonearm), your cartridge could be perfectly aligned with each of the two grids on the Feickert protractor, including the front to back alignment of the cartridge body? Your tonearm is totally unfamiliar to me; is it "vintage" or a brand new product?  If vintage, the tonearm may have been designed for Stevenson alignment, especially if it was made in Japan.  The Feickert is designed for accurate alignment to the Baerwald standard, which is very different from Stevenson.  (Which by the way also means that you should not use the Feickert if you want to try Stevenson alignment.)  I cannot recall whether the Stevenson is "shorter" in pivot to stylus tip distance than Baerwald or Lofgren, or whether it's the other way around, but possibly this is why your alignment appears to work, but you would have had to twist the cartridge body with respect to the headshell to make it work, i.e., to achieve the proper offset angle so the cartridge body aligns with the grids on the Feickert.  Is that the case?  If so, maybe another mystery is solved.

Third, DSGriffith, I don't really follow your argument, but I have to agree with Raul, who after all is agreeing with me.  On the other hand, I take your point that aftermarket headshells or swapping OEM headshells between two different tonearms may complicate the alignment problem. For a given geometry (Baerwald, Lofgren, or Stevenson) with a given tonearm, theory predicts there one and only one "most" accurate alignment (defined as that which gives minimal tracking angle error on average across the surface of an LP).  (I'm aware that Baerwald is identical to one of the two Lofgren methods, A or B.  Can't remember which.)  I am not one who believes you need to be within a micron of "accurate", but 5mm seems a huge error.  There are cases about which I have read where persons in the field have come to disagree with the manufacturer of this or that tonearm on what is really the best P2S distance, etc, for a given tonearm.  This is true for the FR64; FR says 230mm, gurus say 231.5mm.