Rev. 5 – Jun 2020 Page 22 of 91
MACRO SPECTRAL EDITING
The yellow and green areas at the bottom of the module
are, respectively, bands parametric scanning and bands
tilting. These two functions are totally independent the
one of the other. These have been designed to quickly
modulate multiple bands with a few controls. Each of
these parameters has a main potentiometer (C.3, C.6,
C.9, C.12) and its own CV input (C.4, C.7, C.10, C.13)
with a dedicated attenuverter (C.5, C.8, C.11, C.14).
4.2.1 Tilt
The green section is the Tilt parameter (C.3, C.4, C.5).
Assuming a fixed fulcrum in the middle of the 16 bands
(between band 8 and 9), the Bands Tilting allows to grad-
ually emphasize half of the bands, as much as the band
itself is far from the fulcrum and attenuate the other half
in the same way. It is then possible to change the balance
between lower or higher frequencies. The parameter has
its rest at the center. Moving it counterclockwise the
bands from 1 to 8 are emphasized, with an emphasis that
gradually decreases from 1 to 8. At the same time, bands
from 9 to 16 are progressively attenuated, from band 9 to
16.
One of the possible uses of the band tilt is to use it to
temporarily attenuate the lower frequencies’ presence
when the mix is particularly “crowded” in that frequency
range. In fact, feeding the CV with the envelope you use
to create your basses, or passing the audio of the bass
drum through an envelope follower, results in a tempo-
rary emphasis on the higher frequencies. Balance the tilt
with its main pot, and simply play with the attenuator and
envelope follower times to obtain the desired effect.
4.2.2 Parametric Scanning
The yellow section is called Parametric Scanning due to its
similarity to the use of 3 variables as the parametric EQ.
In any parametric EQ, it is possible to set the center fre-
quency, the gain value, positive or negative, also called
peak/notch in some cases, and the slope. Here it is simi-
lar, but it doesn’t work directly as a filter, but as a voltage
control which feeds each band VCA.
The first control is called Peak/Notch (C.6, C.7, C.8) and
it selects the amount of emphasis or attenuation of the
scan: when the knob is at its center, no emphasis is ap-
plied; when it is moved clockwise, a positive gain offset is
applied; when it is moved counter-clockwise, a negative
gain is achieved, which can be useful to perform notch-
filter-like operations.
The Center control (C.9, C.10, C.11) sets where this em-
phasis/attenuation has its maximum/minimum level:
when fully counterclockwise, no band is emphasized; by
rotating it clockwise, the position shifts from band 1 to
band 16; when fully clockwise, no band is emphasized as
well.
With the Width parameter (C.12, C.13, C.14) it is pos-
sible to emphasize nearby bands: you can set a width
from none to all 16 bands (16 bands are audible only if
the Center knob is set to noon).
To bypass the parametric scanning simply move the
Width control completely counterclockwise.
SPECTRAL TRANSFERRING: MODULATION FILTERS AND
ENVELOPE FOLLOWERS
The modulation circuit is designed to perform spectral
transfer between the modulation signal and the main one.
The modulating signal must be patched to the Mod in-
put, which feeds an array of 16 band-pass filters similar
in design to the ones in the main array; then, each filter
feeds a dedicated envelope follower; the resulting 16 en-
velopes create as many different control voltages that are
semi-normalled to the VCA input jacks (C.2).
As said above in the paragraph about the Modulation
Routing, patching a jack into any individual band CV in
will break the semi-normalization of the envelope follow-
ers.
The duration of the resulting envelopes can be modified
with the E.F. Attack and Release control knobs (D.3, D.4).
The leftmost position offers the fastest envelope response;
rotating it clockwise will result in slower envelopes.
Usually, the only parameter in the time domain used to
modify the envelope followers’ signals is the Release time.
FUMANA is equipped with the Attack time as well, in
order to have more control over the harmonic content
modification and obtain more subtle results.
The circuit response is non-linear, meaning that the
knobs allow for more precise control over the fast times
rather than the long ones, which is useful when a signal
with fast transients is being processed. Furthermore,
given that the more conventional use of this circuit is to
perform vocoding-like operations, it is more frequent that
fastest envelopes are required.
Each envelope uses its own independent time-scaling
factor, which is longer for lower frequencies and faster for
the higher frequencies, in order not to cut any audio wave
semi-period.
The envelopes resulting from this spectral analysis are
also available on the 16 E.F. outputs (D.2), which can be
used as CV to be routed to different points of the patch
without affecting their transfer to the VCAs of the main
filters.
An All E.F. output is also provided, which sums all the
envelopes together (D.1).
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