No i dosent have to be unipivot but it seems accepted practice to plonk one a DECCA cart.

The Decca can make a fantastic sound in the right arm, I've heard them on a few occasions sound immense. My tendency would be to use a heavy solid arm because of the vertical and noncompliant cantilever.

used deccas SG/Jubliee/reference in jelcos ,roksan nima/pug unipovits & currently with a Vertere SG-1

What about one of these? :-)

A project im working on

Finished that unipivot I was playing with

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Very good for a lash up

This is the mk2, the original had some issues that the mk2 adresses.
There will be one or two changes to this before its completely done.
Its currently belting out some bowie

There is a shure m97xe in it at the moment, have allsorts of other bits and bobs to try in it

I picked ideas from a couple of arms when designing it, and based some measurements on the shure.

It has fixed headshell holes rather than slots, pinched from the naim aro, adjustment for alignment if needed is done by rotating the base. The pillar hole is offset from the centre so rotating it alters the pivot to spindle distance, partly borrowed from the sme range.

The main dimensions are pinched from the rega rb250 so it would fit on the deck properly as that particular deck plinth was built around the 250.

I measured a couple of carts to see what the stylus to mounting bolt centre distance was, and the average was 10mm with very little variation so it should take most carts without needing any adjustment.

The headshell is fixed and is made of 3mm acrylic bonded directly to the tube. There is a walnut support block underneath that is there to add strength and mass at the cart end. The plastic idea was pinched from the roksan nima.

The tube is 8mm copper, the thin tube idea borrowed from the mayware formula 4.

The arm pillar is 12.7mm hardened steel with a cup machined into the end, and the pin is a hardened steel scribe.
Tracking weight is set by the counterweight and azimuth by a secondary weight at 90 degrees to the tube on an outrigger. Bias is string and weight on another outrigger above the counterweight stub that is on the same plane as the pivot point so it doesnt affect azimuth by pulling above or below the pivot point.

The wiring loom is easily removable and is transfi litz. It exits out of the back of the bearing housing and is plugged into the base so that the wand is completely removable. There is then a din socket on the underside of the base that the output cable plugs into.

The pivot point is on the same plane as the stylus, there is no vertical offset so there is almost no variation in geometry when the arm traverses warps, warp wow is as low as it can possibly be, the geometry sees almost no change in use as there is no vertical offset between the stylus and pivot point.

The centre of gravity of the arm is only 7mm lower than the pivot point to provide as little osscilation as possible whil providing stability. If the c/g is too low this can introduce osscilation. Its a compromise, as too high and the arm wants to fall over.

The materials were chosen based on my ideas on resonance control which seems to have panned out well, as the wand assembly doesnt ring very much, if at all. A mixture of arcylic and walnut at the cart end so a non resonant headshell, relatively soft copper which seems to ring in a completely different way to the ubiquitous aluminium,and is effectively damped by the plastic and walnut headshell, and the walnut bearing housing whuch effectivelt damps the tube and bearing pin, and steel for the stub, damped by a combination of the walnut housing and heatshrink over the stub.

I also went out of my way to centeralize the main mass as close into the pivot point as I could to minimise the effects of that mass on the arm.

Had to really think about this one and what I wanted to achieve. Having clear design goals helps enormously, rather than flailing about in the dark

Was worth it though