Behringer's Proton represents a rare breed of semi-modular synthesizer that doesn't compromise between immediacy and deep sound design. Released as a desktop module that can also integrate into Eurorack systems, it takes the dual-filter architecture from the company's earlier Neutron and expands it into something genuinely more capable.
The heart of the Proton is its dual VCO architecture with continuous waveform morphing between sine, triangle, sawtooth, pulse, and tone mod shapes. Each oscillator includes its own sub-oscillator and can be synced together, while pulse width modulation adds movement to the pulse waveforms. The two voltage-controlled filters are self-oscillating multi-mode designs offering low-pass, high-pass, and band-pass modes, and they can be configured in parallel or series with linked CV control. A multimode wave folder sits downstream to add harmonic complexity and grit. The paraphonic mode is the real differentiator here—it lets you play both oscillators independently with separate pitch control, opening up textural possibilities beyond typical monosynth territory.
Modulation is where the Proton gets interesting. You get two ASR envelopes with loopable, invertible, and bounce modes, plus two ADSR generators dedicated to the filters. Two LFOs with five waveforms offer MIDI clock sync and phase control. The 64 patch points and 68 hands-on controls mean you can patch creatively without needing to, and the semi-modular design works beautifully straight out of the box for immediate performance. MIDI connectivity via both 5-pin DIN and USB keeps it integrated with modern setups.
The Proton has found solid appreciation in the community for delivering genuine analog character and modulation depth at a price point that doesn't require selling gear to fund it. Some users note the interface can feel dense at first glance, but that density translates to real sonic flexibility once you spend time with it. The 80 HP Eurorack width makes it a substantial desktop unit while remaining portable enough for live work.
