Resonance Filter, Parametric Equalizer

Motivation

Parametric Equalizer, Resonating Filter Filter front view.

This is my adaption of the Elektor Formant RFM module as described in Elektor Formant book 2 pg28ff. I put only one filter in this module, so you can build as many as you want or need. It is a state variable filter with variable volume, Q (resonance) and frequency. It is thought to emphasize a certain frequency range. This can be used to reproduce the resonances of acoustic instruments. With the given values the frequency range is 50..2300Hz, Q 0.8..5, vol. 0..1.



Specs and features


Implementation

Schematic

Parametric Equalizer, Resonating Filter filter schematic control board

Parametric Equalizer, Resonating Filter schematic: Control board

Description:

This is basically a SVF. Please refer to the original article(Elektor Formant book2 pg 28ff) and other implementations on the web.


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Calibration

  • None
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Building hints

  • You can adapt the frequency range to your needs. The description can be found in the original article.

Special parts

  • None

Download

Parametric Equalizer, Resonating Filter control board documentation download
Parametric Equalizer, Resonating Filter control board Gerber files download
Parametric Equalizer, Resonating Filter *.fpd file download

Parametric Equalizer, Resonating Filter VCF front view

Parametric Equalizer, Resonating Filter: Front view


Parametric Equalizer, Resonating Filter VCF populated control PCB

Parametric Equalizer, Resonating Filter: Populated control PCB


Parametric Equalizer, Resonating Filter VCF back view

Parametric Equalizer, Resonating Filter: Back view


Parametric Equalizer, Resonating Filter VCF half front view

Parametric Equalizer, Resonating Filter: Half front view


Parametric Equalizer, Resonating Filter VCF side view

Parametric Equalizer, Resonating Filter: Side view


2022 November V 1.2.0

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