Frap Tools Fumana - Dual 16 Bands Spectral Editor
Fumama / fu'ma:na / s.f. [dialect of Modena, from Latin fumus, 'smoke'] - 'fog'. Like specters use to lie into the thick fog (which the Modenese countryside is pretty rich of), so many spectral capabilities and functions do within the thick bands of the 'fumana'.
The Fumana is an all analog dual filter bank with various control to access dynamically these bands. Each filter bank is composed of an array of 16 independent 48dB / Oct bandpass filters. Having two identical filter arrays allows you to use one of those for spectral analysis (of a modulator signal) and the other for spectral re-synthesis (of the main signal). Each array is sub-grouped in odd and even bands (numbering these increasingly from 1 to 16 from left to right). It is possible to apply different signals to odd and even bands, both for main and / or modulator arrays. This, together with the 16 envelope followers connected to each band of the modulator filterbank, and the 16 VCAs connected to each band of the main filterbank, allows the Fumana to perform a single 16 bands or a dual 8 bands analog spectral transfer.
While the upper section provides access to each main filter's direct output, the lower section has 4 voltage controllable parameters to manage two independent functions for further spectral editing: tilt and parametric scan.
The tilt control, as the name suggests, tilts the spectrum adding and subtracting amplitude to the 16 bands, emphasizing lower or higher bands and attenuating higher or lower bands: this is managed only with the green potentiometer.
The parametric scan, instead, works with three parameters: peak / notch, band selector and width. Like in a parametric equalizer, where it is possible to set peak / notch gain, frequency and slope, the Fumana uses three parameters to set which is the centre band to perform this manipulation, then if that band should be emphasized or attenuated and how this action is extended to nearby bands.
In addition to the 16 bandpass outputs, there are 4 other outputs provided: the all bands output, the all envelope followers output, the odd and even bands' output. These two have the options to be inverted in phase with two switches, in order to obtain even more combination when summed together, maybe / also with the 'all bands output'.
Since a spectral transfer tool may be used as a 'vocoder-like-effect', the Fumana provides an input for external noise which may be used for unvoiced (fricative / sibilants) sounds as words containing or starting with s, f, z, ch and other fricative sounds