Operation Manual

26 Parameters
4.2.2 The Filter Module
Ultra Analog VA is equipped with two multi-mode filters.
The filters are patched in a flexible way in order to allow their
use in parallel, in series or any combination of both. For even
more flexibility, the cutoff frequency of the Filter 2 can also
be locked to that of Filter 1.
Each of the multi-mode filters include a resonant low-pass,
band-pass, high-pass, notch and two formant filters which can
be selected using the Type drop-down menu. The order of the
filters can be adjusted to 2 (-12 dB/oct for low-pass and high-
pass and -6 db/oct for band-pass) or 4 (-24 dB/oct for low-pass
and high-pass and -12 db/oct for band-pass) with the help of
the Order parameter. Furthermore different saturation algo-
rithms, selected with the Drive drop-down menu, can be ap-
plied to the filters. The resonance or cutoff frequency of the
filters is adjusted with the Frequency knob while the amount
of resonance is controlled with the Resonance knob. When a
formant filter is used, the Resonance knob is used to cycle between the vowels (a, e, i, o, u).
The cutoff frequency and resonance of the filters can be modulated with different modulation
sources. The Key knob allows one to adjust the amount of variation with the pitch signal from
the keyboard while the Env and LFO knobs are gain knobs applied to the signal received from the
Filter Env envelope and LFO modules respectively.
Let’s now have a closer look at the different filter types available.
Resonant Low-Pass Filter
Amplitude (dB)
Frequency (Hz)
Q=10
Q=4
Q=2
Q=1
Cutoff
Frequency
0dB
−3dB
Slope (dB/Oct)
Figure 10: Frequency response of the low-pass filter.