Being perhaps the most popular version of one of the most iconic monophonic analog synth series of all time is no easy feat, but the Moog Minimoog Model D manages to pull it off. As one of the first non-modular synthesizers, the Minimoog Model D is highly intuitive and requires very little knowledge to use. The model D boasts contouring circuits and three separate, completely original oscillators, one of which can be used as an LFO. Although the Model D was reissued, the '70s Minimoog Model D hasn't depreciated in value, desirability, or style.