This tool enables the user to assess the effects of changing stylus overhang while keeping the original angle of the cartridge in the headshell.
This could be useful where the cartridge angle is fixed and overhang is adjusted by an arm base slide, or where you simply wish to keep the cartridge square in the headshell. You could also use it to assess the use of alternative mounting distances for an arm with no overhang or cartridge angle adjustment.
Note it is very difficult to accurately align a cartridge/cantilever to a headshell and it is recommended that a two-point or arc protractor is used for best results.
Below is a simple illustration showing the relationship between the terms used on this page
Mounting distance - spindle centre to mounting hole centre (normally the same as pivot to spindle distance)
Pivot to spindle - spindle centre to horizontal pivot point of the arm
Effective length - stylus tip to horizontal pivot point of the arm
Overhang - stylus tip to spindle centre overhang
Offset angle - angle between cantilever and a line drawn between the stylus tip and the horizontal pivot point of the arm (not to be confused with headshell angle)
Inner / outer null point - the two points on the arc of travel at which the stylus is perfectly aligned to the groove i.e. null tracking error
Inner / outer groove - the limits of the modulated grooves specified by IEC as 60.325 and 146.05mm and DIN as 57.5 and 146.05mm
Overhang Shift Calculator design and coding by JaS © 2009
Many thanks to Seb for his assistance in putting this page together and to Graeme Dennes for his invaluable tonearm geometry analysis paper
Design and Content © Vinyl Engine 2002-2013