Arm Shape
Arm Shape describes the outline of a tonearm’s tube seen from above: Straight, S-shaped or J-shaped.
Tube taper and arm length are separate specifications. A straight tube can still have cartridge offset: an angle between the cartridge’s direction and the line from the arm pivot to the stylus. Bends in J-shaped and S-shaped tubes can also position the cartridge at an angle. Straight therefore does not mean zero offset.
Arm Shape — Tonearm
The shape helps describe the arm’s construction, but does not tell you how it moves across the record. A straight tube can belong to a pivoted arm. Bearing type, which describes how the arm is supported, is separate too.
Shape alone cannot rank sound quality or establish headshell and cartridge compatibility. Check the exact arm’s headshell connection, cartridge mounting requirements and alignment instructions. For a turntable, check the arm actually fitted.
Sources
- Reading tonearm specifications (Japanese) — Audio-Technica
- Offset angle and cartridge mounting — Goldring
- Tonearm shape and bearing construction — Technics
- Cartridge mounting and alignment instructions — Audio-Technica
- Tonearm shapes and supports (Japanese) — Audio-Technica