The first pedal i opened in the beginning 80 ies was an optical operated Morley volume pedal like the volume side of the Evo. My band mate complained he got only a weak signal out of it. I remember that there was a moving cardboard, which was moved too far, so full light could not hit the sensor. Easy peasy to repair - no solder job required.
Judging by vids the Catalinbread Adineko pedal does a great imitation with only electronic parts.