The KORG Monotron is an old school analog synthesizer in a portable format. Sporting a VCO, LFO and VCF, i.e. a voltage controlled oscillator, a low frequency oscillator and a voltage controlled filter, it sports all the components needed to create the sounds of the future.
For all the makers and tinkerers out there, KORG has released the schematics of this little gem. While you ponder on the details and what to modify you can watch the video below for some Monotron action.