Tonearms are one of the most distinctive items of a turntable. Designs vary from S-shaped, J-shaped, straight, knife-edged bearings, race-ball bearings, gymbal, unipivot, linear tracking, and so on. Its most important function is to ensure that the phono cartridge properly tracks the record grooves and allow it to convert this mechanical energy into a very low electrical signal without adding or subtracting any energy captured by the phono cartridge. To ensure this bearing play should be nil or none and the cartridge compliance specs should be properly matched to the tonearm’s total mass.
Below is a nice example of a Naim Aro unipivot tonearm I recently removed from a Linn turntable as requested by its owner.
This tonearm was designed and built more than 30 years ago and it is still in excellent shape. A very rare example since not so many were built and the first one I’ve personally worked with.
Vic