Monotron

Monotron (stylised as monotron in all lowercase) is the collective name of a series of miniature monophonic analogue synthesisers produced by Korg, a Japanese manufacturer of electronic musical instruments. There are three models in the series: the original Monotron (released 2010), the Monotron Duo (released 2011) and the Monotron Delay (released 2011). The models share a minimalist set of synthesis components, consisting only of a voltage-controlled oscillator, voltage-controlled filter, a voltage-controlled amplifier and a low-frequency oscillator.