Blue Lantern Modules — Voks Analog Filter

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Using the BLM Voks Analog Filter for Dense, Hyper-Complex Percussion (Eurorack)

About the Module

The BLM Voks Analog Filter is a Polivoks-style analog VCF updated with several "hacks" for character and performance.
Key Features: - 12dB Low Pass & 6dB Band Pass (each with its own output) - Normal and "Unstable Brite" modes (switchable) - Internal Limiter Diode (switchable) - Multiple CV and audio inputs (including direct, attenuated, and bipolar FM) - 6hp, 13mA current

This is a filter, not a complete voice, but can absolutely be used for percussion shaping and creative processing.

Patch Techniques for Complex Percussion

1. Percussive Voice Shaping (Filter as Main Sound Source)

Patch a fast, plucky envelope (ADSR with immediate attack and short decay) to both the audio input and either CV or FM inputs. Use the Voks' resonance and brite/unstable mode to make the filter “ping” and self-oscillate, giving you percussive pops or “kick” sounds.
Mult envelopes to clock-divided rhythms to create polyrhythmic bursts through the filter.
Use comparators or logic modules to mix fast, odd-length triggers/gates that control the envelope, resulting in complex—sometimes generative—percussive patterns.

2. Rhythmic Processing & Mutating Loops

Feed rich audio (e.g., noise, digital drum samples, metallic tones) into the filter’s direct input.
Patch rhythmic envelopes, gates, and complex LFOs (e.g., from Pamela’s New Workout, Zadar, etc.) to the CV and FM inputs.
Crossfade between LPF and BPF outputs dynamically using a VC mixer or switch, modulated by yet another polyrhythmic source.
Flick between Normal and Unstable Brite mode on beats or “off-beats” via a gate or manual performance, taking advantage of its unique, acidic filter distortion for variety and punch.

3. Multi-Layer Polyrhythms (Filter as Modulation Target)

Drive the filter cutoff with separate CVs that are clocked to different divisions/multiples of your master tempo. For example: a 5-step LFO for cutoff and a 7-step sequenced envelope for FM.
Combine filtered percussion with highly clocked, rhythmically skewed modulations to create movement and groove—making your drum sequences feel "played" and not looped.
Send the same percussion sound to both LPF and BPF, but modulate depths and timbres differently for superimposed cross-rhythms.

4. Limiter & Distortion for Percussive Cut

The internal limiter (switchable by front-panel) can shape transients, making your drums more punchy and controlled.
Toggle the limiter on and off in-sync with specific beats or sub-patterns, emphasizing syncopation and attack in unexpected moments.

5. Wild FM Percussion

Route clicky triggers or audio-rate pulses to the bipolar FM input, making the filter “chatter” or bark at audio rate or with unpredictable chaos, especially in Unstable Brite Mode.
You can further accentuate this by using sequenced voltages or S&H, clocked oddly against the drum grid.

Pro Tips

Audio Input Overloading: Push hot signals or stack multiple sounds; the characterful clipping of the filter will help your percussion cut through, especially in dense mixes.
External Clock Logic: Use clock dividers/multipliers and logic modules (AND, XOR, etc.) to generate gate patterns that trigger modulations to the filter in non-obvious polyrhythms.

Summary

The BLM Voks Analog Filter is not just for classic synth filtering—it’s an aggressive, personality-driven sound-shaper. With strategic CV and rhythmic modulation, it becomes a powerful tool for hyper-complex, punchy, and uniquely percussive patches in your Eurorack system.

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