Doepfer A-137-1 Wave Multiplier - Manual (Page 3)

doepfer System A - 100 Waveform Multiplier A-137
3
As the amplification resp. the Multiples parameter in-
creases even the peaks of the folded signal reach the
folding levels of the succeeding stage and the signal is
folded once again as shown in fig. 2. As the module
contains 4 folding stages up to 8 foldings are possible (4
at the upper and 4 at the lower clipping level). Conse-
quently the maximum multiplication factor is 9 (8+1). If a
second A-137 module is added even more multiplicati-
ons are possible.
The Harmonics parameter sharpens the waveform slo-
pes and adds some overshoot at the edges - a little bit
like the resonance resp. emphasis function of a filter.
Internally the harmonics feature is realized by an additio-
nal VCA for each folding stage. Fig 3 shows the complete schematics of the A-137
module. For each of the four parameters Multiples,
Folding Level, Symmetry and Harmonics a manual con-
trol and an external control voltage input with attenuator
is available.
The external control of each parameter can be realized
with the usual modulation resp. CV sources: LFO,
ADSR, random voltage, MIDI-to-CV, Theremin, ribbon
controller, joy stick, foot controller and so on. Of course
simultaneous control of several parameters with diffe-
rent CV sources is possible (e.g. Multiples controlled by
and ADSR and Harmonics by a LFO).
As the signals within the A-137 are fully DC coupled the
module can be used to process control voltages too.
Fig. 3: Overall view