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Overhang Shift Calculator

Posted Sep 15th, 2009 by JaS

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.
Effective length

A value is required.invalid inputminimum value 150maximum value 500
Overhang
Offset angle
Arm Type

NEW Overhang


parameter Original Custom
pivot to spindle (mm)
effective length (mm)
overhang (mm)
offset angle °
linear offset (mm)
inner groove (mm)
outer groove (mm)
inner null point (mm)
outer null point (mm)
maximum distortion %
average rms distortion %

Note

  • When adjusting overhang via a sliding base or by moving the tonearm to a new mounting distance, only the overhang is changed
  • When adjusting overhang via headshell slots, effective length, overhang and offset angle are changed
  • Figures for inner and outer groove radii relate to the limits of modulated grooves i.e. those with recorded sound
  • Distortion figures are calculated from samples of tracking error in the modulated groove area

Term definition

Below is a simple illustration showing the relationship between the terms used on this page

 

tonearm alignment

 

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

 

 

Many thanks to Seb for his assistance in putting this page together and to Graeme Dennes for his invaluable tonearm geometry analysis paper