Behringer 1004 Dual Analog VCO Eurorack Module

The Behringer 1004 is a dual analog VCO Eurorack module reproducing the circuitry of the ARP 2500 Series 1004 oscillator, an instrument from the early 1970s that defined a generation of avant-garde and electronic music production. Each of the two VCOs generates five independent waveforms — sine, triangle, square, sawtooth, and pulse — across a frequency range from 0.03 Hz to 16 kHz in two switchable ranges. That 0.03 Hz floor is not a footnote: it means each VCO operates as a slow modulation source as well as an audio oscillator, enabling patch architectures where a single module handles both pitch and movement without requiring dedicated LFO hardware. The waveform combination and inversion outputs at the module's output stage allow complex timbres to be constructed by summing and inverting waveforms before they leave the module — a harmonic mixing capability built into the hardware signal path.

The 1004 is built for synthesists constructing patches in the tradition of large-format analog modular synthesis — a heritage that prioritizes tonal character, modulation depth, and organic instability over the precision and repeatability of digital alternatives. The analog expo-converter architecture that defines its pitch tracking also defines its sound: the slight thermal drift, asymmetric waveform shaping, and saturation behavior that makes a vintage VCO identifiable in a mix are present here by design. In practical rack terms, a pair of VCOs in one module is a genuine space and cost efficiency for a system where oscillator count drives harmonic richness. For producers building semi-modular rigs, composers designing generative texture patches, or engineers restoring classic ARP-inspired signal chains, the 1004 offers the tonal vocabulary of a historically significant synthesizer in a format compatible with any current Eurorack system.