# Blue Lantern Modules — Voks Analog Filter

- [Manual PDF](../../manuals/BLM Voks Analog Filter.pdf)

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[BLM Voks Analog Filter Manual (PDF)](https://www.bluelanternstore.com/store/p133/BLM_Voks_Analog_Filter.html#/)  

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## BLM Voks Analog Filter — Creative Modulation Techniques

The **BLM Voks Analog Filter** is a Polivoks-style Eurorack filter with some unique features, including multiple filter modes, an internal diode limiter, and a switchable "Unstable Brite" mode. Here’s how you can modulate this filter to generate the kinds of sounds you’re after:

### 1. Distorted Percussive Sounds

**Patch Ideas:**  
- **Drive the Inputs:** Send hot drum sounds or sharp envelopes into the **Direct Audio Input**. The internal limiter diode, engaged by the switch, will clip and saturate the signal.
- **Unstable Brite Mode:** Switch to Brite mode for even more aggressive, unstable filtering — perfect for distortion or unpredictable percussive artifacts.
- **FM Input:** Patch an envelope or stepped random CV (from a sequencer or sample & hold) into the **Bi-polar FM input**. Push the FM depth for wild, clangy overtones and pitch-sweep effects. Drum triggers through an envelope into FM can cause “snapping” filter cutoff changes.
- **CV Direct Input:** Use extremely fast, snappy envelopes into the CV input to create filter “thwacks” for each percussive hit.

**Pro tip:**  
Mult your drum or percussion audio to both filter inputs ("Attenuated Audio In" and "Direct Audio In") at different levels to saturate and destabilize the response further.

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### 2. Basslines for Dubstep & Drum and Bass

**Patch Ideas:**  
- **Wobble:** Send your bass oscillator into the filter. Modulate the cutoff via the **CV Direct Input** with a synced LFO. Use shapes like triangle/sine for classic “wobble” (change speed for rhythm variations).
- **FM Bass Growl:** Run a second VCO (preferably an audio-rate one, tuned low or one octave up) into the **Bi-polar FM input**. Set FM depth to taste and watch the filter generate thick, growly harmonics or “talking” bass effects.
- **Distortion:** Engage the internal Limiter Diode and "Unstable Brite" mode for dirtier, agressive drive. Run the filter into heavy feedback with external mixing for even more chaos.
- **Rhythmic Groove:** Patch stepped or synced random CVs into both filter CV and FM inputs for irregular, "talking" or stuttering bassline movement.

**Pro tip:**  
Combine 12dB LP output with the 6dB BP output, mix them externally, and pan or process them for wide/pulsating stereo bass textures.

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### 3. Haunting Atmospheric Pads

**Patch Ideas:**  
- **Slow LFO Sweeps:** Modulate the filter cutoff with a slow, irregular LFO into the **CV input** for evolving, organic timbres. Try mixing triangle and sample & hold modulation for subtle complexity.
- **Bi-polar FM for Texture:** Feed a very slow LFO or audio-rate oscillator (subtle level) into the **Bi-polar FM input** while sending drones into the filter. This provides evolving color and movement, sometimes bordering on ringmod textures if the range is right.
- **Brite Mode:** Use the "Unstable Brite" mode for ghostly, slightly unpredictable resonance and artifact-laden sweeps.
- **Layered Output:** Use both LPF and BPF outputs, EQ and blur each differently (heavy reverb, shimmer, phasing, etc.), and layer for multi-dimensional atmospheres.

**Pro tip:**  
If your pads are too smooth, use the limiter diode to subtly “grit up” the signal, making etheral sounds more emotionally gripping.

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### General Modulation Tips

- **Feedback Loop:** Patch filter output(s) back into input(s) (with attenuation) for self-oscillating or snarling feedback effects.
- **Vary Input Levels:** Using both attenuated and direct ins lets you precisely set how hard you hit the filter, greatly affecting breakup and character.
- **Performance Use:** Assign filter CV or FM input to pressure/aftertouch or an expression pedal for hands-on sound morphing.

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**Module Quick Summary:**

- **2 Inputs:** Attenuated Audio and Direct Audio
- **2 Filter Outs:** 12dB LP and 6dB BP
- **Switches:** Normal/Unstable Brite mode, Limiter Diode on/off
- **Modulation:** CV direct, Bi-polar FM
- **Other:** Modernized for smooth sweep, ancient Polivoks chip for character

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[Generated With Eurorack Processor](https://github.com/nstarke/eurorack-processor)