Not quite an auto-wah and not exactly a phaser, what started out as an exploration of simple op-amp filters morphed into a truly new an unique that responds to the dynamics of your playing unlike any other effect.

Two competing control voltages can be used to interact independently with the VCF in this circuit or they can be made to compete for dominance resulting in complex sometimes unpredictable changes to your instruments tone.

Introducing the Q-Field Generator — an 8-waveform LFO and envelope-controlled “auto-wah” / filter effect designed for guitar and bass.

By combining low-frequency oscillator (LFO) modulation with dynamic envelope-controlled filtering, the Q-Field Generator delivers a wide spectrum of tonal movement — from subtle auto-wah textures and expressive dynamic sweeps to deep resonant modulation and rhythmic filter pulses.

Control Interface

The device features four rotary potentiometers, three sliders, and two toggle switches, providing comprehensive control over level, resonance, modulation, and filter character.

LVL adjusts the overall output level of the pedal.

TRIM allows fine adjustment of the filter’s Q point (resonance), shaping the sharpness and intensity of the peak response.

GAIN controls the amplification of the filter stage, enabling anything from smooth tonal enhancement to more pronounced, driven characteristics.

ENV controls the sensitivity of the envelope generator.

Filter Voicing

Two toggle switches Q1 and Q2 enable access to multiple different filter settings and voices. Q1 UP position engages resonant mode while DOWN position enables shimmer mode. Q2 selects between three distinct Q point settings. These switches alter the filter’s frequency response, providing distinct tonal characters suited to different instruments and playing styles.

LFO Section

The LFO is controlled via three sliders:

• WAVEFORM — Selects from eight distinct wave shapes:

  • Ramp Up

  • Ramp Down

  • Square

  • Triangle

  • Sine

  • Scoop

  • Random Step

  • Random Walk

• FREQUENCY — Adjusts modulation speed from approximately 0.5 Hz up to 300 Hz, covering slow, evolving sweeps through to rapid, audio-rate modulation.

• DEPTH — Controls the intensity and range of the modulation.

These waveform options enable everything from smooth, traditional modulation to sharp, percussive pulses and unpredictable, experimental textures.

Envelope Detector

The envelope detector circuit is engaged by rotating the ENV. potentiometer clockwise. This control determines how strongly the filter responds to your playing dynamics.

• Lower sensitivity requires harder picking to trigger the effect.

• Higher sensitivity allows the filter to react to lighter playing.

This dynamic response enables expressive, touch-sensitive performance and classic auto-wah behaviour.

From psych-rock inspired phase-like sweeps to shimmering, high-boosted wah tones, the Q-Field Generator is a versatile tool for players seeking expanded sonic territory with expressive filter modulation.