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
OK........have just spent the day checking my arms and cartridges :-(
Who said that "Analogue starts with anal"?
Apart from one of my ZYX Universe cartridges mounted in the DaVinci 12" Grandezza and one of my Empire 4000D/III Gold cartridges which is fixed into the Continuum Copperhead tonearm.........all my other cartridges are fixed into removable headshells which have been aligned using Dertonarm's UNI-Protractor with the Fidelity Research FR-66s template and arm mounted at 295mm S to P.

I inserted some random headshell/cartridge combinations into the Micro Seiki MA-505s mounted at the recommended 222mm S to P distance and checked the alignment against the UNI-Protractor with the MA-505 template inserted.
The alignments were almost perfect......but a correction to 223mm S to P distance.....DID make them perfect :-)

I next inserted some random headshell/cartridge combinations into the FR-64s tonearm mounted at the recommended 230mm S to P distance......and lo and behold.......perfect alignment :-)

Moving onto the SAEC-308N with a recommended 235mm S to P distance......I could not make any headshell/cartridge combination align with the correct point?! At the furthest headshell slot.....the stylus point was always 3-4mm too short. Four different headshells were tried with the same result?!
I remember this happening with my Grace 940G tonearm as well....with only one headshell able to stretch to the correct distance?
I then remember what Daniel had written to me about the 235mm distance when he sent me TWO templates for the SAEC-308N......one at the 235mm S to P distance...and another at 225mm S to P??
It is indeed, but it results in a rather "sub-optimal" overhang of 5 mm only.
The resulting tangential curve is catastrophe.
The overhang has to be prolonged.
My template (at 225mm) results in effective length 251.1 mm.
So I moved the armpod to give the alternate 225mm S to P dimension......but of course all my headshell/cartridge combinations did not work!?
The off-set angles and overhangs were totally wrong :-(
They required massive twisting of the cartridges in the headshells to be aligned correctly and only the Yamamoto wooden HS-1AS and Micro Seiki headshells allowed such extreme twisting?
So I selected about 4 or 5 MM cartridges in these headshells...and aligned them according to the UNI-Protractor with the 225mm template.

Ahhhh........the sound....the joy....the bliss!!

So the net result is this:-
I have two tonearms (the Copperhead and DaVinci) without interchangeable headshells.
I have three tonearms with interchangeable headshells which accept any of 20 of my cartridges pre-mounted in their individual headshells...with correct geometry.
I have one tonearm with interchangeable headshell capability (MA-505s).....which has five dedicated headshell/cartridge options ready for instant insertion.

I'm like a pig in mud.....only cleaner.
SO the big question...how does it all sound? How do you choose which setup to use when playing a record? Was it all worth it?
Dear Halcro: Why not align all the removable headshell tonearm designs at 225-227mm according Löfgren A or B calculations?

You could try that: same tonearm effective length, this means same overhang and same offset angle with different tonearm spindle to tonearm bearing mount distance.

Regards and enjoy the music,
R.
Great efforts Halcro and I appreciate your sharing the experience with us. But I
can't fathom the sheer number of choices you have each time you sit down to
relax and listen to music. I sometimes have trouble just deciding which LP to
pull out. How do you do it?
Dear Raul,
Why not align all tonearm designs at 225-227mm?
THE REASON
It ain't a pretty sight huh??.....and most arms should sound their best at their Manufacturers recommended specifications?
But apart from all that......I would then not be able to use cartridges with fixed headshells such as the FR-7f and the Technics EPC100Mk3?

Regards
H