10 Dec 2020 : the boards are now in yellow colour. Circuit and function/performance are exactly the same.
This is an assembled buffer board using JFETs 2SK246/J103 as input. They are connected in cascode topology with another two low noise Toshiba BJT 2SA970/2SC2240 respectively to enhance linearity and extending the bandwidth of operation.
The buffer board can be used as a building block in the audio path, such as a buffer in between the digital audio source and the preamplifier, or even as a preamplifier( gain of 1) by adding a potentiometer at the front.
PCB dimension: 60mm x 38mm.
The board requires a +/-15V DC power supply. Current consumption would be decided by the loading.