doepfer/a-137-1
A-137-1
Voltage controlled waveform multiplier with 4 wave-folding stages, a VCA for Multiples control, and independent manual and CV control over Multiples, Folding Level, Symmetry, and Harmonics parameters. Acts as an inverse low-pass filter, adding harmonics to signals with few harmonics (e.g. triangle or sine). Fully DC coupled.506
Capabilities 3
- CV Processingcv-processing
- Fully DC coupled; can process control voltages in addition to audio signals.506
- Wavefolderwavefolder
- The module multiplies waveform copies within a single period using 4 cascaded folding stages, producing up to 9 wave multiplications. All four parameters (Multiples, Folding Level, Symmetry, Harmonics) are both manually and CV controllable.506
- Waveshaper / Wavefolderwaveshaper
- 506
Jacks 6 — 5 in / 1 out
| Name | Signal | Voltage | Description |
|---|---|---|---|
| Inputs (5) | |||
| CVF | cv | 0V to 5V | 506 |
| CVH | cv | 0V to 5V | 506 |
| CVM | cv | 0V to 5V | 506 |
| CVS | cv | 0V to 5V | 506 |
| In | mixed | — | Audio input of the module; accepts audio signals (e.g. triangle from VCO) or control voltages (fully DC coupled).506 |
| Outputs (1) | |||
| Out | mixed | — | Audio output of the module; outputs the wave-multiplied signal. Can also carry processed control voltages.506 |
Parameters 9
| Name | Type | Range | Behavior |
|---|---|---|---|
| CVF Attenuator | knob | — | Attenuator for the CVF CV input. Adjusts the effect of the external CV on the Folding Level parameter.506 |
| CVH Attenuator | knob | — | Attenuator for the CVH CV input. Adjusts the effect of the external CV on the Harmonics parameter.506 |
| CVM Attenuator | knob | — | Attenuator for the CVM CV input. Adjusts the effect of the external CV on the Multiples parameter.506 |
| CVS Attenuator | knob | — | Attenuator for the CVS CV input. Adjusts the effect of the external CV on the Symmetry parameter.506 |
| Level | knob | — | Input level control. Sets the amplitude of the incoming signal fed into the VCA and folding stages. Connected in series with the Multiples VCA. Should be adjusted so that the full Multiples range produces the maximum effect without excessive clipping.506 |
| Manual Folding Level | knob | — | Controls the distance between the upper and lower folding level. The upper and lower clipping levels are derived by adding and subtracting Folding Level and Symmetry voltages.506 |
| Manual Harmonics | knob | — | Sharpens waveform slopes and adds overshoot peaks at the edges, similar to the resonance/emphasis function of a filter. Internally realized by an additional VCA in each folding stage.506 |
| Manual Multiples | knob | 1 – 9 | Controls the number of waveform multiplications within one period. The VCA gain is set by this control; higher Multiples causes more folding stages to be reached, increasing harmonic content.506 |
| Manual Symmetry | knob | — | Controls the asymmetrical shift of the upper and lower folding levels relative to the zero line. Positive symmetry shifts both levels upward; negative shifts them downward.506 |
Firmware history 0 versions
No firmware history recorded.
References 2
-
[506]
Doepfer A-137-1 Wave Multiplier Manualmanual● verified 2026-05-19
- [507]