System a - 100, A-110, Doepfer – Doepfer A-110 Standard VCO User Manual
Page 11: Pulse width modulation, Vco and divider, Vco and waveform processor

doepfer
System A - 100
VCO
A-110
11
Pulse Width Modulation
If you modulate the pulse width of a square wave with
an LFO or ADSR (Pulse Width Modulation, or PWM),
the harmonic spectrum constantly changes (see p.3,
4). Even with just one oscillator, you can create a
dense timbre with internal movement, in some ways
similar to vibrato, and otherwise only available by using
two oscillators fractionally de-tuned from each other.
Fig. 11: Pulse Width Modulation using an LFO
VCO and DIVIDER
Using a divider like the A-115, you can synthesize up to
three square-wave sub-octaves, and mix them with the
original signal at any level you choose.
Fig. 12: Using the DIVIDER to add sub-octaves
VCO and WAVEFORM PROCESSOR
With a WAVEFORM PROCESSOR you can alter the
symmetry of the VCO’s waveform and positively distort
it, to construct new waveforms.
CV 1
Range
A-110
VCO
Tune
Audio In
F / 2
Audio
Out
F / 8
A-115
DIVIDER
F / 4
In
LFO
PW CV 2
PW CV 2
PW
CV 1
Range
A-110
VCO
Tune