This Module is currently available.
Stromer Mutroniks Electric Bongos
The Stromer Electric Bongos.
Based on the Mica-Sonic Electric Bongos.
Using the exact same transistor-based twin T oscillator circuit as the original.
Each drum tone has a trim pot inside that's been adjusted so that the oscillator is just below the point of self-oscillation. Once triggered, the circuit oscillates at its resonant frequency and rings out like a drum. Pushing in the "mute" button shortens the decay.
To play these you need something that sends trigger pulses, like a beat- or keystep pro, or some old drum machine with trigger outputs.