I'm generally in the same camp as Lewm on this one: I align the
cartridges based on the alignment the tonearm was designed for. Since
most of my tonearms use removable head shells and were designed for a
52mm distance from the head shell connection to the stylus, this has the
added benefit that the cartridge needs minimal if any realigning when
put into another tonearm.
I may be missing something here. I've had a long night on my CAD software and I'm a bit dimensionally challenged at the moment.
If you have two tonearms using universal headshells:
- Tonearm-A with
effective length A
and cartridge-A: the tonearm is designed for Baerwaald and this cartridge/headshell is aligned for Baerwaald
- Tonearm-B
with effective length B
and cartridge-B: the tonearm is designed for Stevenson and aligned as such.
If you swap the cartridge-B/headshell-B combo over to tonearm-A, you would absolutely need to perform a new alignment. I guess I don't get the concept of minimal realignment. It either needs a new setup (alignment) or it doesn't.
Even if both arms were aligned for the same geometry (e.g. Baerwaald), the different effective lengths would mandate a different offset angle..
The whole concept of effective length is a dangerous one, because, two tonearms specified (for example) to have an effective length of 250mm would have different pivot-spindle specifications if one was intended for Stevenson or Loefgren and the other for Baerwaald.
I'm having problems visualizing any scenario where you could make any cross arm swapping work, but I'll ponder this one ;-)
Cheers,
Thom @ Galibier Design