MATRIXSYNTH: Modor Noisy oscillator and Formant filter -Dark Vowel patch

Wednesday, August 14, 2019

Modor Noisy oscillator and Formant filter -Dark Vowel patch

Published on Aug 14, 2019

"Today I have a patch using Modor Noisy oscilltor and Modor-Control Filter, a bit of fun with Vowel using dark patch.
to this I added Black Dual VCF-Erica Synths filter for resonance which can be heard when lfo releases it from time to time by opening the filter .. but all the sound comes from Noisy VCO and Control filter. for this I used a little reverb from the Black Hole DSP module from Erica Synths and changed the filter format to the vowel some time, a slight addition of noise from the Noisy oscillator also causes the filter control to process the noise itself, which seems to create a rather dark effect.

More info about Modor eurorack modules here :

Noisy Oscillator module is and oscillator that mixes two signals: a 'regular' wave (sawtooth/square/triangle) and a 'tonal noisy' wave. This adds a special noisy layer over the sound, that adds 'air', grit or dirt, depending on the combinations you make. The MOD parameter acts on the noisy waveforms:

Sonar Noise: a white noise filtered by a resonant bandpass filter, with 1V/oct tracking of the filter frequency. The MOD parameter controls the resonance.
Wind Noise: white noise filtered by a comb filter, with 1V/oct tracking of the base frequency (delay). The MOD parameter controls a 6dB/oct hipass filter.
Arcade Noise: LFSR noise source as can be found on the SID soundchips (Commodore) or Sega Arcade games. The MOD parameter controls again a 6dB/oct hipass filter.
The noisy wave can be set equal, or 1 or 2 octaves above the regular wave.

The module has two voices, with their own set of CV and output connectors. This can be used to play in a full 2-voice polyphony, or in a 2-voice unison. The outputs can be separate, using both output connectors, or mixed, using only the connector of the second voice.

Next to the 1V/oct pitch CV, the module offers CV control over pitch (FM), the MOD parameter and the sound level:

FM CV: pitch control normalled to 0V, attenuated with the FM knob (+ and -). This allows for Frequency Modulation up to the lower audio range. It's of course a digital module, so higher frequencies can start inducing aliasing and digital artefacts.
MOD CV: CV control for the MOD parameter, normalled to 0V and attenuated with the CV AMT knob (+ and -).
LEVEL CV: CV control for the sound volume, normalled to 7.5V. With this CV control you can omit an external VCA stage if you want.
The CV signals of the second voice (upper row of connectors) are always normalled to the signal of the first voice (lower row), so you can use a single LFO for some FM vibrato or tremolo on both voices, for example. Only the V/oct connector of the second voice is normalled to the first voice with an extra addition of a fixed voltage that can be set using a trimmer at the backside of the module. This way you can use the 2 voices to play in unison with a fixed pitch separation you can set on the backside.

Modor's Formant Filter is a special filter that does a kind of 'vowel morphing' between three vowels. The big central FORMANT control is responsible for that, and on the Eurorack module there's of course a CV control (with attenuation) on this parameter.

You can imagine a formant filter as a set of parallel bandpass filters, picking up and amplifying a set of small frequency bands. For example, with these frequency bands around 750Hz, 1200Hz and 2800Hz, you get the sound of an 'A'. So far, nothing special. There are more formant filters around composed of a set of parallel bandpass filters.

It gets more interesting when you're able to 'morph' between different sets of those formant frequencies. Behind the central FORMANT control, there are 3 of those sets of frequencies. One at full left, one in the middle, and one fully right. So you can for example morph between A-E-O. Or U-I-E. Or AO-UI-EU. Or ...

That's what it does: morphing between different sets of formant frequencies, and that's why it sounds a lot more genuine vowelish than many other static bandpass combinators.

There are 10 preset vowels, that can be selected with the VOWEL button: A-E-O-I-OE-U-EI-EU-AO-U-UI. The vowels of the Dutch language... :-)

The 1-2-3-4 controls on top give you the possibility of composing your own vowels by manually adjusting the frequency bands."

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