Doepfer A-136 Distortion/Waveshaper Eurorack Module
Distortion and Waveshaping Eurorack Module
Module A-135 is a distortion and waveshaping module with extensive control possibilities. The incoming audio or cv signal is internally divided into 3 sections:
positive component of the signal with adjustable clipping level (even externally via jack socket) and positive or negative amplification (+/-) of this component
negative component of the signal with adjustable clipping level (even externally via jack socket) and positive or negative amplification (+/-) of this component
original signal with positive or negative amplification (+/-)
Different settings of 5 distortion/waveshaping parameters enable a lot of very complex and extreme waveform modifications. The range of modifications reaches from simple soft or hard clipping to completely altered waveforms where the original signal is no longer recognizable.
The sketch below shows only a few examples when using a triangle as input signal.
Applications: audio distortion (especially in combination with filters very interesting), waveform modification for audio signals as well as for control voltages (LFO, ADSR, random etc.).
Inputs: audio/CV in, ext. Clipping-Level (+), ext. Clipping-Level (-)
Output: audio/CV out
- For signals beyond 7Vss level the internal pre-amplifier has to be bypassed (e.g. LFO or unfiltered VCO signals). Otherwise clipping occurs before the signal processing takes place. Details how to modify the module are available on the A-100 DIY page.
- Because of mechanical tolerances of the potentiometers and knobs the knob positions may vary a bit from the front panel printing (e.g. "0" is not always exactly the neutral position for "A", "+A" or "-A" with zero amplifiaction).
- The latest version of the module includes a jumper (JP2) at the top edge of the pc board. This is used to select between DC coupling (installed) and AC coupling (notinstalled) of the input signal. For low frequency applications (e.g. LFO processing) JP2 has to be installed.