I have been playing a fair bit with cartridge designs lately and have come to the realization that setup (mainly SRA) can have a profound impact on the sound of a cartridge. When trying to make apples to apples comparisons of different suspension types or silver vs. copper wound coils, small changes in SRA will quickly swamp out the variable you are trying to isolate.
My 12" Schick has been my goto arm for these comparisons since cartridges installed in headshells are a must for efficient changes. That means for these experiments my Schröder Reference sits idle. The realization of the importance of matching SRA from cartridge to cartridge had me add VTAF to the Schick for quick and repeatable changes in VTA. This left me counting turns and computing changes from a known thread pitch. Around four hours ago Jeffrey pointed me to a table he used at a show with a machinists indicator to read out VTA. 
When it comes to simple listening pleasure of a single field coil cartridge the Schröder gets cued up as the daily driver.
I recalled that I had a similar indicator and to the cad/cam program I went. A few hours later I came up with something that would make my long lost uncle Rueben proud. The end result tells me the VTA setting to the 0.001" over a 1" range which is just what is needed to dial in 5 different cartridges with different tie-back wire types for my next comparison.
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Good work, you always do interesting stuff!
ReplyDeleteNoting your set up with the DTI, the adjustable version of the AudioMods Tonearm is fitted with a micrometer screw gauge for setting the arms height and hence VTA, accuracy is .01mm. There are obviously other arms with similar arrangements.
Karl