I’ve bought a little driver with a range of 0-50Ncm. I think the Rega one is preset for 40Ncm, which seems rather high to me, my usual setting by feels is more in the range of 5-10Ncm. I’ve not tried it on the cartridge bolts yet, I can’t access them without disturbing the alignment but the counterweight grub screw, VTA locking screw and cartridge mounting plate bolt are all accessible and have an audible effect on playback. I’ll get systematic with it once my Royal N comes back from Ortofon. I expect there will be some cartridge dependency as to what is optimum.
