UDO Audio’s Super 8: Filter Self-Oscillation and Sonic Alchemy

UDO Audio’s Super 8 is introduced not just as a powerful hybrid polysynth, but as a machine that rewards creative patching. In this video, Hazel Mills demonstrates how the instrument’s filter can be repurposed as a self-oscillating oscillator—a classic analogue trick that’s made refreshingly accessible here. By silencing the main oscillators and cranking up the resonance, the filter begins to generate its own tone, opening up new avenues for sound design.

This approach isn’t just a technical curiosity; it’s a practical way to squeeze more voices and timbres out of a single synth. The method is presented as a “hack” that’s available across UDO’s Super Series, but the Super 8’s interface makes it especially immediate. The video sets the stage for a deep dive into tuning, calibration, and layering, all stemming from this foundational filter trick.

Hazel walks through the step-by-step process of achieving self-oscillation. With the resonance set high, the filter starts to sing, but initially, every key produces the same pitch—hardly musical on its own. The magic happens when key tracking is engaged, allowing the filter’s pitch to follow the keyboard and making it playable across the range.

This isn’t just about flipping a switch; the video makes it clear that the filter’s behaviour is inherently analogue, with all the quirks that entails. The result is a tone source that’s both flexible and characterful, but also slightly unpredictable—perfect for those who appreciate a bit of wonkiness in their patches.

Getting the filter to track pitch accurately requires a bit of calibration—a nod to the realities of analogue circuitry. Hazel demonstrates the process: a quick key combination triggers an auto-tune routine, complete with a charming R2D2-style sequence. Once completed, the filter’s pitch tracking becomes much more reliable, making it suitable for melodic duties.

Even after calibration, the Super 8’s filter retains its analogue soul. Users can tune the filter to concert pitch using the cutoff knob, either by ear or with a tuner, or by matching it to one of the main oscillators. This flexibility lets you decide whether you want pristine tuning or prefer to embrace the inherent drift and character of the circuit.

The Super 8’s dual-layer design offers even more creative headroom. Hazel points out that everything demonstrated so far is possible on just one layer—doubling up opens the door to complex, evolving textures. By assigning different sounds or intervals to each layer and using panning to separate them in the stereo field, users can craft intricate, spatially rich patches.

This final section is a call to arms for adventurous programming. The video encourages users to combine layers, modulations, and filter tricks to create sounds that go far beyond standard subtractive fare. It’s a fitting conclusion, highlighting UDO Audio’s commitment to hands-on, exploratory synthesis.