This issue of the interrelationship between effective length and pivot to spindle distance has perplexed many a sophisticated turntable owner.
Even manufacturers like SME make compromises fixing the cartridge location in the headshell (no slots), and thereby not accounting for varying stylus positions relative to the mounting bolts.
If you can establish your effective length, then you can use the John Ellison spreadsheet on the Free Stuff section of the Enjoy the Music website to establish the correct pivot to spindle distance.
This spreadsheet has a Baerwaald tab as well as a Loefgren tab. I have a link to that page on the Support Page of my website. Frank Schroeder and I consider it an invaluable tool and a great gift to the audio community from John.
It may disagree with what FR has defined as the ideal alignment as many of the Japanese tonearms have ideas that vary from those of Baerwaald and Loefgren.
The archived threads on this forum relating to the Mint LP arc style protractor have a lot of good general information which attempts to cut through many of tho common misconceptions about the relationship between the three parameters: eff. length, pivot to spindle, and offset angle.
I also have a thread on my forum relating to this topic. It's something that's worth chewing over, to better digest. I maintain a permanent link to this thread on the lower right section of my home page - considering it to be THAT important to one's understanding of this topic.
Cheers,
Thom @ Galibier
