Eurorack Reference / modules /doepfer/a-105-2 audit site v0.1 — milestone 3
doepfer/a-105-2

A-105-2 24dB SSI Low Pass Filter

Doepfer

Voltage controlled 24dB/octave lowpass filter based on the SSI2144 chip (successor to the SSM2044), with two audio inputs and CV control over frequency and resonance.323

Visualization filter_response

Capabilities 1

Low Pass VCFvcf-lowpass
24dB/octave lowpass filter based on the SSI2144, self-oscillating, with two audio inputs and two frequency CV inputs.323

Jacks 6 — 5 in / 1 out

NameSignalVoltageDescription
Inputs (5)
FCV1cvFrequency CV input 1, no attenuator, approximately 1V/octave tracking.323
FCV2cvFrequency CV input 2, with attenuator knob.323
Input 1audioAudio input 1 with level attenuator knob.323
Input 2audio≤15VAudio input 2 without attenuator. Max input voltage without clipping: about 15Vpp.323
QCVcvResonance CV input, with attenuator knob.323
Outputs (1)
Outaudio≤15VFiltered audio output. Max output voltage without clipping: about 15Vpp.323

Parameters 5

NameTypeRangeBehavior
FCV2 attenuatorknobAttenuates the frequency control voltage applied to socket FCV2.323
Frequknob15Hz – 15000HzManual control of the filter cutoff frequency.323
Input 1 LevelknobAttenuates the audio signal applied to socket Input 1.323
QknobManual control of the filter resonance, adjustable up to self-oscillation.323
QCV attenuatorknobAttenuates the resonance control voltage applied to socket QCV.323

Firmware history 0 versions

No firmware history recorded.

References 1

  1. [323]
    Doepfer A-105-2 24dB SSI Low Pass Filter product pageproduct_page
    verified 2026-05-14