doepfer/a-120
A-120
Voltage controlled 24dB/octave transistor ladder lowpass filter with three CV inputs, manual cutoff frequency control, and resonance adjustable to self-oscillation.209
Capabilities 4
- Lowpass Filterlowpass-filter
- 24dB/octave transistor ladder lowpass filter with three CV inputs summed to control cutoff frequency; resonance adjustable to self-oscillation.209
- Self-Oscillationself-oscillation
- Classic 24 dB/oct Moog-style ladder LP; self-oscillates at max resonance producing a clean sine.209
- Sine Wave Oscillator (self-oscillation)sine-oscillator
- When resonance is set near maximum, the filter self-oscillates and behaves as a sine wave oscillator, trackable via V/oct CV 1 input.209
- Vcfvcf
- Voltage-controlled 24 dB/oct Moog-style ladder lowpass filter.209
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. Level is controlled by the Lev. attenuator knob.209 |
| CV 1 | cv | — | Standard V/oct voltage control input for the cutoff frequency. Works on 1V/octave rule like VCOs. Use for pitch tracking or oscillator pitch CV when using the filter as a sine oscillator.209 |
| CV 2 | cv | — | Voltage control input for cutoff frequency modulation; level controlled by the CV 2 attenuator knob.209 |
| CV 3 | cv | — | Voltage control input for cutoff frequency modulation; level controlled by the CV 3 attenuator knob.209 |
| Outputs (1) | |||
| Audio Out | audio | — | Output from the filter carrying the filtered audio signal.209 |
Parameters 5
| Name | Type | Range | Behavior |
|---|---|---|---|
| CV 2 | knob | — | Attenuator knob controlling the level of the CV voltage applied at the CV 2 input, affecting the intensity of modulation on the filter cutoff frequency.209 |
| CV 3 | knob | — | Attenuator knob controlling the level of the CV voltage applied at the CV 3 input, affecting the intensity of modulation on the filter cutoff frequency.209 |
| Freq. | knob | — | Adjusts the cut-off frequency. At maximum (10), the filter is fully open; at minimum (0), the filter is completely shut with no output signal.209 |
| Lev. | knob | — | Controls the amount of audio signal entering the filter input. If output distorts, turn this control down unless distortion is desired as a special effect.209 |
| Res. | knob | — | Adjusts the filter resonance (emphasis), emphasising frequencies around the cutoff. Near maximum, the filter self-oscillates and behaves as a sine wave oscillator.209 |
Firmware history 0 versions
No firmware history recorded.
References 2
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Doepfer A-120 24dB Low Pass Filter Manualmanual● verified 2026-05-06
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