As those familiar with that device already know, the Formant Filter specializes in vowel morphing. Using the large Formant knob allows users to shift between three vowel sounds—and of course, this parameter features full CV control! But that is only the beginning, because while the aforementioned control morphs between three sets of frequencies, the Vowel button gives users access to ten preset vowels. Users also have the ability to create custom vowels by adjusting the frequency bands via the four horizontally-configured knobs at the top of the module. These configurations can be stored by pressing the Shift and Vowel buttons simultaneously.