Since Behringer's first synth release in 2016, it has become more affordable than ever to own and explore classic analog, digital, and hybrid digital synths. For the adventurous musician who desires a deeper dive into the unique and unlimited possibilities that modular architecture synthesizer systems provide--Behringer has you covered with a wide range of Euro-rack compatible solutions.

From complete modular systems like the Behringer System-55- to a vast selection of individual voltage-controlled oscillators, filters, envelopes, amplifiers, sequencers, triggers, and even digital modules, Behringer offers everything needed for the player who wants to build a truly unique and personalized system.

When it comes to vintage analog low-pass filters, there is no greater holy grail than the self-oscillating 4-pole “ladder” style filter found in the “System 55, 34, and 15” of the early 1970s—and in Behringer’s modern recreations of each. Brimming with the fat, gritty, overdriven character you’d expect, the Behringer 904A is an essential addition to your Euro-rack or third-party compatible modular synth set-up at an outstanding value.

Loaded with THD polyester capacitors, the Behringer 904a circuity is a faithful recreation of the original design, with the benefit of modern stability that vintage ceramic caps notoriously lack. On the control surface, the Frequency range (filter cutoff) dial has three frequency cutoff bands (1HZ to 5kHz,4Hz to 20kHz, and 16Hz to 80kHz) for comprehensive control over filter sweeps. The freq-range (resonance) dial controls how much resonance feeds into the filter. Additionally, 3 summed CV control inputs were used to manipulate fixed control voltage from multiple LFOs and other modulation inputs.