Moody Way is a touch-sensitive vocal effect, “autowah”. It is based on two bandpass filters and you can also get vowels other than the classic A-O-A. The two filters put a “talking character” on the sound and you adjust the two center frequencies with the Tone and Voice knobs. With different settings you can find E, I and Ä and possibly U and Y.
The pedal has an Up / Down control knob. In the end positions of this knob, the sweep goes either up or down over the filters. For moderate impact, you can back a little from the end positions. In the middle position, the pedal acts like a fixed wah wah with two tone knobs.
The Envelope control knob sets how fast the response should be to a note on the guitar. The Voice knob has its own response circuit and in different positions it sweeps over the band to further enhance the sense of speech.
With Resonance in max, the sound can be sharp and you can back a bit from max for a more moderate wah sound.
The bandpass filters are built on two LM13700 chips. Moody Way should be powered with a 9V DC “center negative” power supply (not included). True bypass.
Text and logo is an engraving.
A spoken vocal is largely defined by two bandpass stops, “formants”, f1 and f2, in the spectrum of the voice. For example, for an I f1 = 240, f2 = 2400. And for vowel e, f1 = 390, f2 = 2300 (reference: wikipedia).