p-mount cartridges

A resource for p-mount phono cartridge users

Stylus Profiles

There are three basic types of stylus profiles, which offer varying degrees of accuracy when tracing a record groove.

  • Conical (or spherical)
  • Elliptical (or bi-radial)
  • Line Contact
Line contact styli include Shibata types (named after their inventor at JVC who developed it to reproduce very high frequencies for CD-4 quadraphonic records), Fine Line, Fritz Gyger, and other manufacturer trade name variations). Advanced line contact shapes are ground with ridges to allow greater contact with the groove, for example Shure MR, and Jico SAS.
 
Though the stylus has a large part to play in the sound of a cartridge, the cantilever that holds the diamond stylus tip and the generator (the body of the cartridge) also play a big part, which is why some conical cartridges can actually sound very good. Generators (for p-mount types) can be either moving magnet (which allows user replaceable stylii) or moving coil (where the cartridge needs be sent to a speciallist for re-tipping). The only p-mount moving coil cartridges available now (in limited numbers) are high output versions which can use the moving magnet phono input of amplifiers/phono stages (eg. Ortofon X1-MCP).
 
The diagrams and tables below are from the Japanese Jico company, who make quality replacement styli for a wide range of cartridges, including their advanced shape Super Analogue Stylus (SAS) - which easily equals, or in many cases exceeds the performance of the OEM stylus, and is the replacement stylus of choice for those wanting the very best sound quality. They also manufacture (reportedly) the Shibata stylus used by LP Gear for their Reference VS series AT-based p-mount cartridge.
 
The diagrams show how the more advanced stylus profiles sit lower in the groove and, with their narrow front-back profile (very narrow in the case of the SAS) are able to follow the groove more accurately with the tangenital contact area more closely aligned with that of the original cutter head.
 
There is a lot of detailed information on stylus shapes to be found in this thread on VinylEngine. 

Stylus tip shape and specification

 

 (Diagram: Jico) 

Groove contact

 

 

(Diagram: Jico) 

 

 

  

 (Diagram: Jico)

The relation between stylus tip shape and contact surface

 

(Diagram: Jico) 

Stylus insertion angle

 

 (Diagram: Jico)