This is a very cool and versatile tremolo by Electric Druid. The signal path is taken from the Tremulus Lune, but the LFO is replaced with a digital chip with tons of features: Tap Tempo, 8 different waveshapes (even a random shape!) and a multiplier function. If you are new to digital chips that require code, read more in my Guitar to MIDI post. Have a look at my finished build here.
Read more about this project and download the HEX code or buy the PCB/pre-programmed chip-kit here: http://www.electricdruid.net/index.php?page=projects.taplfo
I also drew up this layout with only the LFO, Figured it might come in handy. For example to modulate the speed of a delay to create some pitchbend/chorusy effects... Hmmm, wonder how that random waveshape will sound. :o) I have not built this one yet, but it should be ok. Hook up A and B to any pot you want to modulate/replace. Use a regular LED and wrap it in heatshrink or tape with the LDR or use a vactrol. I used a VTL5C3 vactrol in my build.
All the layouts are Verified unless noted.