Blackbird / SME

Go on Amazon and search for Technics Head shell weight. One should do it. If your resonance frequency winds up too low you can shave parts of the weight off with a Dremel tool to get it right 8-10 Hz. get the Hi FI News test record.

Viridian, the effective mass of the detachable head shell version is 12.5 gms. This version is 9.5 grams not 6.5. There is absolutely nothing wrong with that vertical bearing it is just expensive to make. Every arm has some "secondary" resonances the better tonearms are usually well dampened as I am sure the SME is. The Blackbird has a compliance of 12 X 10 -6 cm/dyn which is on the lowish side. This arm is a little light for this cartridge. The detachable shell version would have been a better match but that can be fixed with a little added weight and a test record.

The resonance frequency with that arm and cartridge is 11.27 HZ. Those numbers are damn good! Why would you need a headshell weight?