Triplanar VII tonearm & Koetsu Jade Platinum cart.

I had the Jade in 3 different arms. Suffice it to say it is a very low compliance cartridge. You have not heard a Jade until you hear it in a high mass (over 28 gm) arm. This brings the bass and treble into focus and gets the Resonant frequency outside of the audio band and actually to an ideal 11 Hz (using the HF test lp). In my system it performed wonderfully in an Ikeda 407. A high mass 12 inch arm. I would suggest any of the variants is ideal. You can also add mass to the arm as suggested.

In the case of effective mass, it is a different calculation than the mass of the arm. I am not 100% sure but I feel it relates to inertia. In the case of a Dynavector arm the effective mass can be altered by using a high mass headshell. On the inexpensive side use some blue tack. Place it under the headshell or on top and some on the counterweight. It is cheap enough an experiment (About $10) to learn the effects of mass. This renders most tonearm upgrades / swaps superfluous since now you are able to test mass changes rather than arm changes. Using a penny stuck on top of the headshell w. blue tack can do the trick as well. Just use a test record before & after & determine your resonant frequency. Listen before & after the change. You should easily learn the difference. Unless the arms bearings are not up to it you should be able to easily hear how mass relates to compliance and effects freq. response. Good luck.