Behringer BM-17 Frequency Box: Analogue VCO Unleashed for Guitarists and Synth Heads

Behringer’s BM-17 Frequency Box isn’t just another pedal to sprinkle a bit of reverb or fuzz onto your sound. Instead, it’s a full-blown analogue VCO, the very heart of a synthesizer, squeezed into a stompbox format. The video makes it clear from the outset: this isn’t about subtle enhancement, but about adding a whole new instrument to your setup—whether you’re wielding a guitar or a synth keyboard.

For guitarists, the BM-17 acts as a second voice, ready to be triggered and modulated by your playing, while synth players will recognise it as an extra oscillator, capable of thickening textures or running as a standalone lead. The presenter likens it to unleashing a genie from a bottle, but instead of granting wishes, it delivers outlandish, sometimes alien, sounds that push you well beyond the familiar territory of traditional effects. The BM-17 is positioned as a device that encourages sonic exploration and a willingness to dive into the unknown.

The heart of the BM-17 is its wave shape control, allowing users to morph the oscillator’s output from one waveform to another with a simple twist. This isn’t just about static tones; the video demonstrates how the pedal can serve as a continuous drone, a synced pitch follower, or an extra layer in a synth patch. The flexibility here is all about how you choose to interact with the box—there’s no single right answer.

Envelope following is another standout feature, letting the pedal dynamically track the amplitude of your playing and translate it into pitch movement. Play softly and the pitch remains low; dig in and the frequency soars. The BM-17 can also be used to add a new layer to your synth rig, or simply to create wild, unpredictable noises by turning every knob to its extreme. The device’s versatility is highlighted by the presenter’s playful suggestions, from reanimating basement creatures to (jokingly) unlocking your front door.

Modulation is where the BM-17 really starts to show its colours. The envelope amount knob determines how much the envelope follower affects the VCO frequency, giving you expressive control over pitch based on your playing dynamics. This is especially noticeable in hard sync mode, where the pitch locks to your input and produces a growly, wah-like effect as you dig in.

The FM (frequency modulation) control is described as an unexpected twist—adding a layer of sonic unpredictability and complexity. By adjusting the FM amount, users can introduce everything from subtle vibrato to full-on alien textures, depending on the modulation source and settings. The video’s dry humour aside, it’s clear that the BM-17 is designed to reward those who aren’t afraid to experiment with amplitude tracking and modulation, making it a powerful tool for creative sound design.

The BM-17’s rear panel is described as a treasure trove of connectivity, opening up a wealth of integration options. The video demonstrates patching the LFO output from a Behringer Neutron into various CV inputs on the BM-17, controlling FM amount, frequency, and even sweeping through wave shapes. This level of modular-style patchability is rare in a pedal format and makes the BM-17 a flexible addition to both pedalboards and Eurorack setups.

Experimentation is the name of the game here. By leveraging the BM-17’s I/O, users can explore cross-modulation, external control, and complex signal flows that go far beyond the typical pedal experience. Whether you’re running it as a standalone synth voice or integrating it into a larger modular ecosystem, the BM-17 encourages users to get hands-on, patch cables at the ready, and see just how far this “freaky little beast” can go.