Saturday, November 19, 2022

Kojo Technology Crystal E Ground Box and Crystal EP Plug


Kojo Seiko Co. Ltd is a medium sized company located in Hirakawa City in Aomori, Japan. Established in 1990, they are involved in a variety of electronic related businesses ranging from power supply design and manufacturing to audio accessories.


The Crystal EP is a virtual earth product that improves the grounding of audio equipment. The device is a barrel shaped plug with various connectors available :- RCA, 3.5mm mini plug, banana and spades. The barrel contains 100 cm2 of high purity aluminum foil treated with a special etching process to create cavities that increase the surface area to 11,000 cm2. The rear of the Crystal EP plug unscrews to accept a grounding cable for connection to the optional Crystal E Ground Box. 

The Crystal E Ground Box is a compact metal ground box that houses an eight layer plate structure that functions as a virtual ground. The plates comprise a combination of stainless steel, brass and copper plates. The plates are stacked, with a 0.5mm air gap between each plate. The box measures 80mm (W) x 35mm (H) and 111mm (D) and weighs 775 grams.

Picture taken from Kojo's website

There are two screw terminals at each end of the box. One terminal is used to connect the grounding cable to the component or Crystal EP plug, while the other end is used to daisy chain a second Crystal E Ground Box. Two ground cables of 1.2m length are thoughtfully provided in the package, one with spades on both ends, and the other with a spade and RCA plug.

You can use the Crystal EP plug alone, or connected to one or more Crystal E Ground boxes. Alternatively you could use the Crystal E Ground connected directly to the component in question. 

To be continued ....


No comments: