Eurorack Reference / modules /synthesis-technology/e430 audit site v0.1 — milestone 3
synthesis-technology/e430

E430 Morphing SVF

Synthesis Technology

Faithful re-creation of the classic Oberheim SEM 12dB/oct state-variable filter with individual LP, BP, Notch, and HP outputs, a voltage-controlled Morph output, and voltage-controlled resonance. Built from period components including LM301, LM741, RC4558, CA3080-class OTAs, and discrete JFET current buffers.426

Capabilities 3

Multimode Filtermultimode-filter
Simultaneously outputs LP, BP, Notch, and HP responses, plus a morphing output sweeping between selected responses.426
State-Variable Filterstate-variable-filter
Based on the Oberheim SEM state-variable topology using CA3080-class OTAs and discrete JFET current buffers between filter sections.426
Vcfvcf
12dB/oct state-variable filter based on the Oberheim SEM design, with LP, BP, Notch, and HP simultaneous outputs plus a voltage-controlled Morph output.426

Jacks 12 — 7 in / 5 out

NameSignalVoltageDescription
Inputs (7)
1V/Octcv-5V to 5V1 volt per octave control for the filter frequency.426
FM 1cv-5V to 5VFilter frequency modulation input. FM 1 is an inverting attenuator (attenuverter).426
FM 2cv-5V to 5VSecondary filter frequency modulation input.426
In 1audio≤5VAudio signal input 1.426
In 2audioAudio signal input 2.426
M CVcv-5V to 5VCV input for voltage-controlled morphing of the Morph output.426
REScv-5V to 5VCV input for voltage-controlled resonance.426
Outputs (5)
BP Outaudio-6V to 6VBandpass filter output.426
HP Outaudio-6V to 6VHighpass filter output.426
LP Outaudio-6V to 6VLowpass filter output.426
MORPH Outaudio-6V to 6VMorphing filter output, sweeping between LP and HP through either BP or Notch depending on the LED pushbutton selection.426
NOTCH Outaudio-6V to 6VNotch filter output.426

Parameters 8

NameTypeRangeBehavior
FM 1 LevelknobInverting attenuator (attenuverter) for the FM 1 CV input.426
FM 2 LevelknobLevel knob for the secondary FM CV input (FM 2).426
Filter MorphknobSweeps the Morph output between LP and HP, passing through either BP or Notch depending on the LED pushbutton setting.426
FrequencyknobSets the initial filter frequency.426
Input 1knobLevel knob for audio input 1.426
Input 2knobLevel knob for audio input 2.426
LED pushbuttonbuttonSelects the middle response of the Morph output. OFF (unlit): Bandpass is used for Morph sweep. ON (lit): Notch is used for Morph sweep. LED color is user-programmable.426
ResonanceknobSets the initial filter resonance. No self-resonance unless patched externally.426

Firmware history 0 versions

No firmware history recorded.

References 1

  1. [426]
    Synthesis Technology E430 Morphing SVF product pageproduct_page
    verified 2026-05-16