Build a wogglebug http://www.musicsynthesizer.com/WoggleBug/WoggleBug.html PCB etc here: http://web.pdx.edu/~rfahl/img/Wog/ > - Build the low pass gate found on fonik.de. > Usuable PCB design but that 3PDT centre-off switch is impossible to find. Why not use a rotary switch ? it will work fine! HTH Mike