TT Arm-base Unipivot vs Gimbal-base Designs...

Steve at VAS has a BIG VPI setup, with a uni-pivot arm base, with a nearby shelf, with a collection of uni-pivot arm wands with various cartridges. He tests, and demonstrates cartridges he builds/re-builds there.

It sounds terrific!

The base has VTA on the fly, ... and each arm wand has a mini din connector to a nearby din/rca junction box. pull the din connector out, lift the arm wand off, set it down, place the other arm wand on, connect it’s mini-din to the junction box, ready to play! Single arm base is one set of cables to phono stage which is adjustable/pass for MM.

Steve’s setup takes more area, there is no dust cover, thus not for me. My 3 tonearm setup is 3 gimbal arms, less area, removable dust cover. Mine is 3 sets of arm cables to a SUT, front selector for which arm, then select loading or Pass, then off to MM input.

More than 3 cartridges, a friend’s cartridge, it’s gotta be mounted in it’s own headshell for the Acos Lustre Arm with VTA on the fly.

Switch headshells: if cartridge body is a different height, adjust VTA (easy), then: azimuth has to be carefully confirmed/adjusted, both tracking force and anti-skate adjusted. And, when I go back to my cartridge/headshell: reset VTA, azimuth, tracking, and anti-skate.

I’m very quick, been doing it for many years, and got the hand coordination of the Acos-Lustre arm down, tools at hand, but it ain't instant.

I did not see Steve reset tracking or anti-skate when switching arm wands/cartridges, I need to ask him about that.

I gotta say, 3 cartridges he built (2 for me, 1 for a friend) sounded terrific on his uni-pivot arm wands.

Uni-pivot arms have zero friction. Period. That is their principal advantage. Gimbal designs have to be made with much care to the beatings, and with enough care (and expense) the friction can be made so low as not to matter. No doubt but that both arms can be made to sound great. No apparent sound advantage of one over the other with proper design.

I am amused at those who can’t abide the slight wobble when handling a uni-pivot arm. How they can put up with all of the inconvenience of analog and be bothered by this little thing is beyond my understanding.

That being said, I use a second (sapphire) pivot on my 12" VPI 3D arm. It does get rid of the wobble, but that never bothered me. I do it principally because it makes setting azimuth (which I do by ear) much easier. I consider careful azimuth setting the most important of all stylus adjustments. It is almost impossible to do easily on many (most?) of the popular gimbal designs.

Yes, a lot of care to the beatings . . . but also to the bearings.  Sorry for the typo.