What considerations apply to material selection for cartridge mounting bolts?

@lewm 

"Supercar Blondie"

I had never heard (of) her but she sounds normal to me!

Maybe a bit posh - the way an Oz accent changes when its near money.  One really annoying habit common to younger Oz women is that they raise pitch at the end of a sentence and immediately launch into the next one.

I had been thinking of linking cars I have ridden in to my Garrard and Holbo turntables.

I think the Garrard equates to a pre-war blown Bentley two seater sports car - gnarly powerful motor, heavy chassis, clunky controls, surprisingly smooth ride.

The Holbo is like a Citroen DS (goddess) - sleek, button controls, rises when switched on, one of the best rides ever

@richardbrand 

"Nah Ostraaaaihliah - down undah"

Oops! I should have known that. I think I recall you mentioning that somewhere. My apologies.

Have you guys tried this resonance calculator? I found it helpful when I was looking for a cartridge that would work well with the tonearm on my Luxman turntable. If your cartridge's weight is expressed as um, type (it's__um = dynamic compliance) in your browser's search bar and it will calculate the figure in Hz, then you can find the intersection on the table for your arms total mass including your cartridges weight.

The golden range may not be exact as expressed in the graph but you'll get very good results when you test your resonance vertically and horizontally with a test record. I got 10Hz vertically and 9Hz horizontally.

You should also consider the weight of an optional counterweight as I did since the cartridge I chose (9.5g) was at the upper limit of the tonearms standard counterweight, so I purchased the optional heavy one. This helps keep the counterweight closer to the gimble improving the distribution of mass.

https://www.vinylengine.com/cartridge_resonance_evaluator.php

@faustuss 

No worries, cobber!  (I'm really a ten-pound-pom anyway - though I have been neutralised).

Thanks for the resonance tip.  Still learning this stuff.  I have not tried the cartridge resonance calculator yet, but I will.

It is a bit challenging because for most arms, there is only one effective mass.  The Holbo has two - vertical and horizontal and they are very different.

The 70-kg squishing my Sorbothane probably resonates at under 4-Hz

I do have a Tacit test record and an oscilloscope, but I think I have to brush up my German to make much headway.

Playing the test record without the ’scope, there were no obvious audible resonances on my Holbo system ...

@richardbrand 

In my haste to throw my two cents in I keep ignoring the fact that that you're trying to optimize a tangential arm and not a static one.

I was referencing to a resonance test that is manual using visual observation to determine the arm assembly's actual resonance frequency using a swept tone in phase for horizontal and out of phase for vertical where the tonearm and cartridge assembly will visually oscillate at whatever the natural tendency is for that mass and compliance. It would require some form of intervention if not in the optimum range.

Since I haven't a clue regarding the operation of a tangential arm I'll defer but hope anyone who happens on this thread will find our exchange useful to their endeavors setting up a traditional tonearm. Thanks for your consideration anyway.