12 inch Graham Phantom

Dertonarm,

Longer isn't always better. Some have complained that it hurts. Some like it shorter, some like it thicker, some thinner, and some like it just the way it is. For each there is an optimum length, thickness. Basically we are looking for that perfect synergy. Without it you need to move on.

I forget what I am talking about, women or cartridges?

Dgad, it certainly all is a matter of perspective ......
Length never hurts - if applied with expertise and skill.
Those poor souls who prefer short and thin will still have a wide selection.
Given the fact that the 10" are rare and the 12" are even scare.
Those lucky few who have experienced the advantage of the long versions applied with skill, will never again settle for less -neither skill nor length.
And they KNOW why.
And - yes, I recall! - we were talking tonearms.....

The relaxed handling with a long one and its improved contact area to the side walls can create a different reproduction of tones.

LOL. Try and keep this under control. This thread is well on its way to be deleted.

I think Peter at North Audio also carry some long ones.

I have also seen some >18" ones made with exotic african wood material.

o.k. - back to the mere prosaic world of analog-highend audio.
If the rigidity of a given tonearm AND its moving mass AND its ability (if there is any ability) to transfer energy is NOT diminished by the increased length of the armpipe - then the advantage in minimized geometrical error will show off in "improved" (whatever that is..) sonic presentation.
So - if all strong points of a given tonearm-design are preserved while increasing its length - and thus decreasing its geometrical error (tangential...) - then the longer version will be the "better" version.
As with everything in our physical sphere, there is a "window" or "frame" of superior function under the given mechanical circumstances. Below 9" the error in a pivoted design becomes too large to allow serious high-fidelity sound (at least to my ears). Above 12-13" there will be very few plinth/turntables around to accommodate a tonearm of that length. Furthermore the further minimization in tangential error will be so little, that it won't show off any more in real-world set-ups.
Between 9" and 12" there is a significant improvement in tangential error and the toenarms of that effective length still do show reasonable rigidity and moving mass.
Compare the 12" to the 10" versions in tonearm-designs like the SME, the Ikeda, the Phantom II, the Fidelity Research FR60s-series. While the differences are subtle, they are there. Clear and in all the different designs of the tonearms just mentioned, they are showing in the same direction.
I like it when physical laws and geometry show their impact in analog.
Not all is myth or voodoo.