Eurorack Reference / modules /rare-waves/grendel-formant-filter audit site v0.1 — milestone 3
rare-waves/grendel-formant-filter

Grendel Formant Filter

Rare Waves

Four analog bandpass filters in parallel, plus a control voltage processor to articulate vowel-like tones from your audio input.490

Capabilities 2

Formant Filterformant-filter
Four analog bandpass filters in parallel with CV-controlled articulation of vowel-like tones via two-dimensional IPA Vowel Chart mapping.490
Multiband Filtermultiband-filter
Backfilled via CAPABILITY_IMPLIES (formant-filter is a multiband-filter); direct insert because full re-ingest would regress existing jack rows

Jacks 4

NameSignalVoltageDescription
Inputs (4)
Articulator X CV Incv-10V to 10VIdeal voltage range for controlling Articulator X is +/-2.5 volts or 0..+5 volts.490
Articulator Y CV Incv-10V to 10VIdeal voltage range for controlling Articulator Y is +/-2.5 volts or 0..+5 volts.490
Audio Inaudio—490
Size CV Incv-10V to 10V490

Parameters 4

NameTypeRangeBehavior
Articulator Xmenu_setting—Works together with Articulator Y to select vowel tones from a two-dimensional map related to the IPA Vowel Chart.490
Articulator Ymenu_setting—Works together with Articulator X to select vowel tones from a two-dimensional map related to the IPA Vowel Chart.490
Modeswitch0 – 2490
Sizemenu_setting—Moves all four bandpass filters in parallel, affecting the overall size of the filter's 'mouth'.490

Firmware history 2 versions

VersionReleasedNotes
2.22022Updates include: choice of black or silver panel in brushed anodized aluminum, a 3-way Mode switch for choice of bypass/Mode 1/Mode 2, less distortion, and higher input impedance at CV In and Audio In jacks.490
2.02012490

References 1

  1. [490]
    Rare Waves Grendel Formant Filter product pageproduct_page
    source 490 canonical ↗ archived ↗
    ● verified 2026-05-17