Gimbal vs unipivot tonearms

Mijo, the Goldmund T3F LT tonearm was a straight up ripoff of the Rabco SL8E, which was designed by an engineer who lived here in bethesda, MD, not a gnome in Switzerland. I always wondered whether it was done under a contractual agreement, and if not, whether there was a resulting law suit. Both of those tonearms  would have been prone to generate noise, and neither of them was a true linear tracker, because the action of the tonearm depends upon the stylus inscribing a tiny arc which then activates a switch which then turns on a motor that moves the pivot end of the arm wand down its track. Back in their day at one time or another I heard both, and I actually did not perceive any issues, but the demonstrations were usually in audio salons under poor conditions for critical listening. You are old enough to have heard them as well. Did you really like them in comparison to a good air bearing linear tracking tonearm? I never made that comparison myself.

There is as much difference among different air bearing tonearms in terms of these same issues as there is between a Unipivot and a gimbal bearing pivoted tonearm. It would take a separate thread to sort that out.

Still waiting for your Cosmos?

Mijo, As I recall, the early 3D tonearms from VPI were warping at temperatures where a $4K tonearm, or any tonearm, should not warp.  Like temps reached during shipment or on a very warm day in a non-air conditioned environment.  But they did fix the problem, so far as I know.

In fairness to VPI, I think they long ago fixed the problem with warping of their 3-D tonearm due to heat. And the uniform 3-D structure is touted as an advantage, not a cheap shortcut as you imply.

Classic SME tonearms used a "knife-edge" bearing, which is definitely different from a unipivot but does allow for some "chatter".  Mijostyn mentioned this in responding to Elliot's erroneous suggestion that his older SME tonearm was a unipivot.  As I understand it, modern SME tonearms (like the IV and the V, maybe) have either done away with the knife-edge principle or have modified it to make it more stable, similar in philosophy to what Graham and Kuzma have done to stabilize the pivot bearing on tonearms that started out as unipivots.  I own a RS Labs RS-A1 tonearm that is a very crude unipivot, and 7 other tonearms that are gimbal type. Also, I used to own the British tonearm that used a mercury bath to establish electrical continuity between the arm wand and the base; I can't recall the brand name, but I am guessing Keith Monks.  With all its faults (and the danger of mercury exposure), that tonearm had a kind of airy quality that was pleasing.  So too does the RS Labs, which performs way above its very oddball design. However, I confess it is not in use at this time.