Why do tonearm specifications list null points?


I happened to be going through the manual that came with my Clearaudio Universal 12" tonearm and noticed they list inner and outer null points, 66.04 and 120.9 respectively, along with all the other specs. 

I was under the impression that tonearm geometry can be set to anything you want to use (Lofgren, Baerwald, Stevenson, custom) by setting it up with the specified spindle to pivot, overhang, and angle settings using a tonearm protractor, e.g., Dr Feickert, etc.

So, is the tonearm manufacturer trying to say that this particular tonearm is somehow optimized or was designed to utilize those null points they list in the spec?

128x128jimmy_jet

Showing 1 response by mijostyn

@dover , right on. 

@rauliruegas exactly, overall distortion levels are lower with Lofgren B except at the very innermost part of the record. Modern records are not cut that far in. Som older records are but I do not notice significant problems with records cut all the way in and I Use Lofgren B religiously. It is tedious setting up a cartridge correctly especially if you are trying to change alignments. Any tonearm set up for Lofgren A can be made to do Lofgren B but to do it accurately and consistently you need a protractor like the WallyTractor or the SmarTractor. You need a mirrored surface with lines finely etched and magnification.