Mark Keppinger and I welcome those who wish to build or learn about vacuum tube "Kepp" theremins. Mark has produced two models; the Mark 1 and the Mark K. The Mark 1 design is established; while the Mark K PC board design is still in the debugging phase by the group's members who have prototype boards.
We were invited graciously by Jason Barille to post on this site. Our group of builders and experimenters has been posting on the Yahoo group, kepptheremins, since January 2009.
We all hope to learn about the lost art of vacuum tube electronics and help each other in our respective endeavors. Vacuum tubes do have a unique and warmer sound, some will argue, than conventional solid state designs.
Mark's designs are free to all who wish to use them.
Have a blessed, safe, and productive New Year!
Respectfully yours,
Mark Keppinger and Philip Neidlinger