12 inch arms

The 12" versions which were made, were based on the current model at the time. Therefore the first were based on the RP1-X, and later versions on the xg2. They were all J-shaped tubes with rectangular headshells.

These pics courtesy of Topclass Audio,  shows the 12" arm with the damper unit.

John, at Audio Origami, has made a couple of tubes for a customer. There is an interesting, and lengthy, thread on Vinyl Engine which describes the process (and illustrates how confusing some people find tonearm design theory).  It was this thread, drawn to my attention by a friend, which has ultimately led to this blog.

Recently I have made some custom arm tubes using other configurations. These included an S-shaped variant (above) using the original headshell, and a straight variant using  a new headshell with a different offset angle (below).

 The straight option involves a new headshell angle, which means that the vertical movement no longer pivots on the same axis as the linear offset. In other words the headshell describes a slight arc as it moves up. However this is minimal compared to the SME 3012 or any other arm with the vertical bearings aligned at right angles to the arm tube. Not that it is a big concern, unless you have a liking for playing extremely warped records...

This option is not as massy as the J-shape. I have supplied it to the client and await his comments. A drawing of the original 12" J-shape is in the geometry page.

I found this pic (below) of the arm (again courtesy of Topclass Audio) on a Kuzma XL, which must be the chunkiest mount the arm´s been used with.

Below is a chrome 12" (Rp1-Cr12) on a maple plinthed Garrard 301

More 12" arms here