Back in 1979, the original RSF Kobol Expander stood out as a rare alternative to the Minimoog, packing patchable versatility into a semi-modular frame that let synthesists go wild beyond basic leads and basses. This Behringer take faithfully revives that spirit in a compact 80HP Eurorack module, measuring just 94 x 424 x 136mm, ready for desktop use or rack integration.
Dual VCOs deliver thunderous low-end with seven continuously morphing waveforms—from sine to square—spanning 10Hz to 10kHz without octave jumps, plus sync, PWM, and FM patching for wild harmonics and effects. A brutal 24dB resonant filter adds natural saturation and low-end bite on resonance, paired with snappy dual envelopes, a single LFO, and a voltage processor for scaling signals or mixing with overdrive. No patching needed to start, but dozens of CV/gate points, external audio in, USB/DIN MIDI, and duophonic play unlock deep modulation, polychaining, and signal processing in your modular setup.
Folks love its refined, punchy character—fat basses between an Odyssey and Moog, percussive hits, and evolving drones—that complements other analogs like the Neutron without redundancy. Reviews highlight the fun of its straightforward layout and affordable entry to hands-on analog tweaking, though tuning can drift like any warm VCO rig.