4 Voice drone-machine
This is a drone machine consisting of four identical oscillators. Each oscillator can be tuned by two potentiometer; course and fine.
A patch-bay on the instrument are used to cross modulate the different oscillators, through frequency divisions.
The machine also have a tone-control and volume control for controlling the output.
The drone machine is based on four CD4060 chips with 4 counter stages as outputs. Sixth division is going into the mix. modulation can be done to each chip through the mod input (notice LED direction). Should work with up to 20VDC.