Check out the beautiful Benjolins by Derek Holzer aka Macumbista! I’ve had the pleasure to see his work up close and was very impressed!

The Benjolin is a standalone synthesizer designed by Rob Hordijk from the Netherlands. It contains two oscillators (one LFO and one VCO), a voltage controlled filter and a circuit called a “Rungler”, which allows chaotic cross-modulation possibilities between the different parts of the circuit. Hordijk refers to the Benjolin as a circuit which has been “bent by design.”


These hand-made Macumbista Benjolins have been further customized with a patchbay, which can be used to interface with other modular synthesizers or to setup further control voltage feedback systems within the Benjolin itself, attenuators on the three control voltage input and LEDs displaying the internal state of the Rungler.

The patchbay of these Benjolins has banana jack connections for the square and triangle waveforms of each of the two oscillators, the Pulse Width Modulation output of the two oscillators, the Rungler output, the XOR (exclusive/or) logic operation of the two oscillators and the output of the filter.

There are also banana jack control voltage inputs with attenuators for the frequency of each of the two oscillators and the filter cutoff frequency. The layout of the panel is designed to be both intuitive and playable (unlike many EuroRack modules, for example…). And finally, the three output bits of the Rungler have been visualized with red, green and blue LEDs.

A double version, the Butterfly Benjolin, allowing incredible amounts of chaotic cross-modulation between the two halves, is also possible.


These Benjolins are produced under licensed agreement with Rob Hordijk.

More information can be found on the Macumbista website - you can even order one there!

The Rungler that plays a big part in the Benjolin personality is also available as a 5U module: The Rungler