Envelope Filter

The Envelope Filter is a professionally designed, competitively priced tone modifier which enables you to create a wide variety of "wa-wa" sounds. A voltage-controlled, low-pass filter in which the upper cutoff frequency is determined by the amplitude, or level of the input signal. The louder the signal, the higher the cutoff frequency. The loudness of the signal therefore controls the "brightness" of the sound.
The Envelope Filter may be used with any electric keyboard or stringed instrument, including guitar, bass and piano. The Envelope Filter will add variety and expression to both solo and accompanying performances.

Controls:

• Threshold (Sensitivity) – adjusts envelope sensitivity, defines how strongly the input level triggers the filter sweep.
• Attack – Sets the rise time of the filter, introduces a delay to let sweeps build gradually
• Emphasis enable more or less pronounced filter peak
• Up/Down (Reverse Sweep) allows the filter to open downward instead of upward—i.e. louder attack lowers cutoff instead of raising it. Useful for unconventional, reversed wah effects
• Filter Range allows switchable filter cut-off ranges—you can switch between lower-frequency sweep vs higher-frequency sweep for brightness or funk depth

The Envelope Filter it’s known for its dynamic, fluid, and organic response. It reacts differently to pickup level, playing force, or amp impedance. It’s less about precision and more about expressiveness—with a lively, vocal-like filter that breathes with your playing.

With the emphasis knob, quack becomes sharper. With reverse sweep, you can explore unusual, alien-like wahing. The range mod lets you tailor the sweep from deep bass funk to bright, cutting tones. These mods retain the analog character while expanding expressive possibilities.

True Bypass
Power: 9V DC center negative