Fulltone Wahfull is a custom shop pedal and designed for Robin Trower. It is a fixed-wah effect with a live-size frequency knob.
Based on the circuit of the original pedal they added a Volume Control, 3 selectable Range Modes (Wacked, Jimi, and Shaft) , a Pickup Compensator mini knob (humbucker guys rejoice!), and JFET input and output buffers. These buffers completely isolate the circuit from outside influence and are only in-play when the pedal is ON, giving it a much broader range of wah effect, interfacing with all types of Pick Ups better, and working with any amp whether it be hi-gain or clean. Turns a Fender into a Vox, and allows infinite sustain with little or no Distortion.