Multiple arms, multiple cartridges and geometry?


I have read the debates regarding the benefits of different tonearm geometries......Lofgren A and B, Baerwald, Stevenson etc....and I appreciate the benefits of choosing where, on the vinyl record, one wishes to have the least spread of distortion.
I also have read where certain arms seem to perform better with one or other of these geometries?

I have two turntables with three different arms on each one and I have a total of over twenty five different cartridges.
Four of those arms have removable headshells and twenty of my cartridges are mounted on their own headshells ready for installation into any of those four tonearms.
How then.......can I have different geometries for each arm if I don't wish to re-align a cartridge within its headshell depending on the arm in which its installed?
Surely......I must select a single geometry for all my arms so that the cartridges fixed to their headshells....are truly interchangeable?
128x128halcro
Dear Mapman,
Your alignment template works for your tonearm. It's specific to the Linn tonearm. I cannot imagine how to design a "standard template" that is turntable specific. The turntable does not give a rat's butt what tonearm is mounted on it, so long as the tonearm will fit on the mounting platform. I don't think off the top of my head that there is any way to escape the necessity of re-aligning each cartridge for each tonearm, unless the two tonearms have identical length parameters and headshell offset angle.

But, Halcro, I just remembered that you do use outboard arm pods that can be moved around freely wrt your TT101. This gives you more degrees of freedom wrt P2S distance, but won't completely obviate the need for tonearm-specific alignment.
Dear Henry, You need, it seems, to start a new. I hope that
you own no more then 400 Lp's so you can rearange them according to the distance of the outer groove to the spindle. Assuming 3 geometries you will have then 3 kinds
of LP's collections which is 3x more then we, the other, have because we own just one collection. Then you should mark all your tonearms according to the new ranking or geometry while the same should be done with the carts/headshell combos. This way you will have 3 kinds of every kind while thanks to the markings no confusion
will ever (more) occur.

Regards,
Dear Nikola,
Que??.........
Lew.......you're right about my ability to 'massage' the spindle to pivot distances for all my arms.
I'm thinking......and I may be wrong (need to check the Vinyl Engine formula)....... Whether I can adjust the P to S dimension of all the arms to have a uniform 'overhang' dimension?
Will that allow for a 'common' interchangeability?
Regards
Henry
Dear Halcro: I think that I don't explain to good or that you did not understand what I posted, here again:

first I don't know why you want differnt geometry alignment for each tonearm ( Baerwald, Stevenson, L¨fgren or what ever. ).
If you need full interchangeability you must choose one geometry alignment for all tonearms.

When we choose in that way, example: Löfgren B, even if the tonearm effective length is different from each tonearm we can force the calculations to one effective length for all the tonearms, in this way the overhang and offset angle will be the same to all tonearms and with full interchangeability.

Subject is to choose the " right " effective lenght value that permit the cartridge overhang set up for all tonearms. So, if for example you choose: 260mm that means that all tonearms must be mounted to conform that effective length minus the calculated overhang.

This could do it or not depending how large are the true tonearm efective lenght differences between each of the four tonearms. So, not always is possible to have that full interchangeability.

Regards and enjoy the music,
R.
Henry - for the arms you use that have detachable headshells, surely if you use a headshell that has slots, hence the ability to alter the overhang and alignment, then you can set each cartridge up and the only changeover issues would be tracking weight and VTA. I use to build easy VTA adjusters by tapping a metal block and using a fine thread screw to put under the arm lift. If you recorded the optimum for each cartridge/arm then it becomes easy to adjust.
Failing all this - buy 2 more TT's & enough arms and you can at least get 24 of your cartridges running simultaneously.