Jico Super Analog Stylus Range

By Luigi Papagno,   Category: Blog

Jico Super Analog Stylus Range

Jico of Japan have been making superb styli for a long time now. We have been using and recomeding them especially in our favorite Shure V15 III and V15 V . The SAS series is however somthing special and below we expain why.

1. The Jico SAS Profile Tip

SAS Stylus profile illustratio showing diamond cut and polish detailn

The tip of the Super Analog Stylus is carefully chosen from single-crystal natural diamonds. The laser-cut diamond closely resembles that of the cutting stylus used on a cutting lathe to produce the acetate master disks used in vinyl production. This allows the SAS tip to reach into the deepest recesses of the record groove in order to retrieve details which were previously inaccessible to other stylus profiles. Due to its wide contact area with the groove wall, the SAS can reproduce a more expansive bandwidth of information with higher fidelity.

Featuring a line contact profile in the shape of a narrow ridge only a few microns in width, the SAS tip achieves a curvature of radius not previously available in similarly shaped styli. The curvature of this profile is optimized to distribute effective mass, thereby eliminating excess pressure on the record groove wall and reducing distortion introduced by uneven wear. Additionally, the tip is polished to the highest standard to preserve the record and extend the use of the stylus.

2. Cantilever Construction

Boron

Jico SAS Stylus on Boron Cantilever

Boron is one of the most suitable materials for cantilevers; its density is low, Young’s modulus is large, and the speed of sound propagation is approximately 2.6 times faster than that of aluminum. Due to the characteristics above, boron cantilever can more precisely trace the information contained in the record grooves than aluminum cantilever.




Sapphire

Jico SAS Stylus on Saphire Cantilever

The reproducibility of the sound engraved on analog records is further enhanced by adopting sapphire for cantilevers since sapphire has high rigidity. Compared to aluminum cantilevers, every single sound will be defined more clearly, allowing the users to enjoy crystal-clear sound.





Ruby

Jico SAS Stylus on Ruby Cantilever

Similarly, the SAS/R enjoys all the sapphire benefits with one crucial advantage: The four facets of its crystalline ruby cantilever taper toward the diamond tip. This tapered ruby cantilever design allows for lower moving mass, giving the SAS/R even greater ability reproduce vibrations in the record groove with precision, accuracy, speed, and fidelity. Facets of the tapered ruby cantilever can be seen in the image below. Cuts made to the cantilever reduce the moving mass of the diamond stylus tip.





3. Single Point Tension Wire Suspension

Jico SAS Cantilever suspension detail

In order to transmit vibrations from the stylus tip to the transducer magnet faithfully, the cantilever is supported by a specially constructed suspension. A single strand of ultra-fine piano wire is attached to the cantilever which then passes through the magnet before being secured internally to the housing. This helps to stabilize the movement of the magnet and reduce distortion from resonance that builds up as oscillations are transmitted through the cantilever, thus preserving the original signal down to the smallest detail.

 

4. Specially Formed Rare Earth Magnet

Jico SAS Cantilever suspension detail 2

To extract the maximum performance from the single point tension wire a specially shaped magnet is mounted coaxially to the cantilever. The magnet is composed of rare earth elements, the magnetic strength and reduced weight of which give it exceptional properties for use in this applicatio

 

Contact Surface Area as a Function of Stylus Tip Profile

SAS Stlus comparison chart

The chart below depicts several types of stylus profiles viewed head on and in cross section. Also seen are the measurements of their tip radii and the surface area in contact with the record groove wall. Profile radii (R) are measured in microns (µ). Surface area in square microns (µ2) is calculated using measurements L1 and L2. Variations in the size and shape of the stylus tip affect the amount of surface area which can be applied to the groove wall. By optimizing its curvature and reducing the minor radius, the SAS tip maximizes the contact surface area by a factor of 1.25 in comparison to other line contact styli.

Points of Contact with the Record Groove During Reproduction

Jico Stylus profile comparison with cutting head

As the record rotates the orientation of the groove wall changes relative to its point of contact with the stylus. At the microscopic level the undulations of the groove present various angles to the diamond tip. Because the SAS tip mimics the shape of a cutting stylus, it sits more comfortably in the groove. The better the stylus fits the record groove, the less distortion occurs at high amplitude reproduction.