Dunlop Cry Baby

Named after the Vox Cry Baby pedal it imitated, the Dunlop Cry Baby became synonymous with ‘wah pedal’. Although there have been many versions and countless classic tones created with it, the core circuit has remained largely stable since the 60s

The classic ‘waka’ sound is pervasive across funk...

The wah was originally developed to emulate the sound of a muted trumpet, and when combined with a rocking treadle, allowed for a hugely expressive range of filter sounds to be created. An early and progressive adopter was a young guitar virtuoso named Jimi Hendrix, who had already seen the brass parallels with the electric guitar when he dubbed it the “public saxophone”. Whether filtering feedback and sustained notes through a wall of sound or adding percussive clicks to the opening of Voodoochild, Hendrix remains the wah master.

At the core of the circuit is an active bandpass filter, created using an inductor. The filter is centred at around 750Hz, where it delivers 18db of boost, and attenuates out-of-band frequencies. On the original GCB-95 model, the sweep available from the treadle was from about 450Hz to 1600Hz. Later developments, such as the bass version, change the frequency range - although it’s also relatively simple to add additional boost or alter the Q - that is, the severity of the curve - of the filter.

Used as a variable filter, rather than as a tool to accent individual notes, the Dunlop Cry Baby has a distinctly different character. By rapidly sweeping the treadle, a ‘waka’ sound can be generated as the filter brings out treble in the guitar, particularly if the guitarist is using pick scratches. This classic sound is pervasive across the funk genre, and it also features in a number of iconic police show soundtracks too.