FX25B

The DOD FX25B Envelope Filter is an analog envelope-controlled filter pedal introduced in the 1990s, designed for electric guitar and bass. It produces an automatic wah-like effect by adjusting the filter frequency in response to playing dynamics, creating expressive, vowel-like sweeps without requiring a treadle. Three controls provide sound adjustment: Blend determines the balance between the dry and filtered signals, Sensitivity adjusts how strongly the filter responds to the instrument's input level, and Range sets the frequency range of the filter sweep. The pedal is housed in a durable green metal enclosure and can operate from a 9V battery or a compatible external 9V DC power supply. Manufactured in the United States, the FX25B is an updated version of the original DOD FX25 Envelope Filter.