Another interesting link. http://korfaudio.com/blog there are 4 posts on cartridge matching in the blog and a calculator, read the blog posts first. |
I have the test record mentioned by Chakster, it was thrown in when I bought my last cartridge, an SPU Royal N. Before fitting the SPU to my arm (Schröder) I ran my Proteus through the resonance tracks. Arm eff mass 13g, compliance 13, cartridge weight 7.8g, 0.9g for the screws (I weighed them). The Vinylengine calculator https://www.vinylengine.com/cartridge_resonance_evaluator.php?eff_mass=13&submit=Submit gives a resonance frequency of 9Hz for this combination, on the test record there was warble from 14Hz down but visible wobble only at 7Hz. Fitting the SPU involved changing an aluminium cartridge mounting plate for a brass one, this raises the arm’s effective mass to ~18g plus whatever effect moving the counterweight half an inch further back has but I’ll ignore that. So for the SPU eff mass is 18g, cartridge and the adaptor that comes with it 15.9g,screws and nuts 1.5g and the compliance 8. This gives a resonance from the calculator of between 9 to 10 Hz, on the test record I initially didn’t see any wobble with the setting roughed in but after a couple of weeks of fine tuning by ear I ran the test again and this time it wobbled at 7Hz. The Korf calculator, which I hadn’t found until later, offers an explanation for what is going on. |
