Guys, Bottom line is that the HFNRR test LP is not good for determining tonearm/cartridge resonance because the actual recorded frequencies do not necessarily match what the label says, at least as claimed by several knowledgeable contributors on VA. Stringreen, might not the expected extra stiffness of the suspension, due to age, just about counteract the error you note above regarding tonearm mass?
Raul, Thanks for the poop on the DV501. If the information is correct, and if it does apply to the DV505 as well, it would seem that I would be advised to find a very lightweight headshell for auditioning high compliance cartridges. Something that is not much more than 5-6 gm. Do you have any candidates? The DV505 stock does work well with the Ortofon M20FL Super, however, possibly because it is not so high in compliance compared to other MM/MI types.