I believe the Dyna arm is also to heavy for your SOTA.
i have a 505 and have found it lovely sounding on a DP-75 custom constrained layer plinth. Ive used the following MC cartridge on it FR-MK2, Dynavector 17 D3, Lyra Delos, Koetsu Urishi Black, and a Kuzma CAR-40. For MM both a Signet TK-9 and Grace / Soundsmith Ruby OCL. As Lew mentioned headshell selection important. I use the stock Dyna HS but replaced leads.
I also have the latest version of Triplaner and find it superior, by a fair bit in both resolution and PRaT ( don’t read the thread on that ). My observation based on idential TT, isolation, armboard but with wiring and setup differences between the two arms Surface mount arms certainly reduce variable.
I also have a 12” Ortofon, which so far has eluded me in clearly besting the Dynavector.
I can also attest to USA Dynavector distributior as providing FANTASTIC support.
