doepfer/a-102
A-102 Diode Low Pass Filter
Reproduction of a legendary voltage-controlled diode ladder lowpass filter. Uses diodes (instead of transistors) as frequency-controlling elements in the filter cascade, resulting in distinctive resonance and frequency behaviour where the two parameters are not fully independent. 24dB/oct slope, self-oscillation capable.326
Visualization filter_response
Capabilities 2
- Self-Oscillationself-oscillation
- At near-maximum resonance, the filter self-oscillates producing a sine wave; can be used as an auxiliary VCO with V/oct tracking via CV 1.326
- Vcfvcf
- Diode ladder lowpass filter with 24dB/oct slope, 3 CV inputs, self-oscillation, and interdependent resonance/frequency behaviour.326
Jacks 5 (4 in / 1 out)
| Name | Signal | Voltage | Description |
|---|---|---|---|
| Inputs (4) | |||
| Audio In | audio | — | Audio input to the filter; patch in output from any sound source such as VCO, noise generator, or mixer.326 |
| CV 1 | cv | — | Standard voltage control input for filter cutoff frequency; operates on 1V/octave rule.326 |
| CV 2 | cv | — | Voltage control input for filter cutoff frequency; level attenuated by CV 2 knob.326 |
| CV 3 | cv | — | Voltage control input for filter cutoff frequency; level attenuated by CV 3 knob.326 |
| Outputs (1) | |||
| Audio Out | audio | — | Filtered audio output.326 |
Parameters 5
| Name | Type | Range | Behavior |
|---|---|---|---|
| CV 2 | knob | — | Attenuator controlling the level of the CV signal at input CV 2, setting the modulation intensity of that input on the cutoff frequency.326 |
| CV 3 | knob | — | Attenuator controlling the level of the CV signal at input CV 3, setting the modulation intensity of that input on the cutoff frequency.326 |
| Freq. | knob | — | Adjusts the cutoff frequency above which the filter attenuates all frequencies. At maximum (10), the filter is fully open; at minimum (0), the filter is completely shut with no output signal.326 |
| Lev. | knob | — | Attenuator controlling the amount of signal entering the audio input. Should be reduced if the filter output distorts (unless distortion is desired).326 |
| Res. | knob | — | 326 |
Firmware history 0 versions
No firmware history recorded.
References 2
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[326]
Doepfer A-102 Diode Low Pass Filter manual (English)manual● verified 2026-05-14
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[327]
Doepfer A-102 Diode Low Pass Filter product pageproduct_page● verified 2026-05-14