Double Buffer, containing a JFET input buffer and a standard NPN transistor output buffer. The build docs are explaining the many ways of using this circuit.
This kit contains the PCB and all necessary parts.
Here is the bill of material: bill of material
This project is by PCB Guitar Mania, in collaboration with Musikding. If you have any problems with the contents of the kit, please contact Das Musikding (Klaus). For technical problems please contact PCB Guitar Mania: PCB Guitar Mania support.
Here is the direct link to the manual with layout and schematic: