The Bassballs pedal is a twin dynamic envelope follower for electric bass, working well with guitars too. The effect uses two dynamic filters that respond sensitively to attack variations, creating shifting peaks and notches, thus producing vowel-like overtones. The switchable distortion mode produces warm harmonic distortion, intensifies the overtones and amplifies the deep resonance of the effect. The "Sensitivity" control determines how sensitive the filters are to playing dynamics. Hence the musician tailors the Bassballs' sound according to the output level of the particular instrument. It is housed in a black, folded steel chassis and came packaged in a distinctive pine box while the last series came in a cheap cardboard box.