Oberheim OB 12, Руководство по эксплуатации

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OB 12 Z-Domain Synthesizer
8.1 EDIT OSCILLATOR 1
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they have been described in section 7).
Alongside the name (or code) of the parameter whose function is being discussed, in round
brackets you will find the full name of the parameter and of the panel control found in the section
whose contents are being explained, used to modify the parameter in question. If the description
of the panel control is accompanied by reference to the section in which it is found, this means
that the control in question also appears in other sections of the front panel.
In real musical instruments, there is always a mechanism which transforms a mechanical action
(pressing a keyboard key, for example) or a fluid dynamic effect (blowing into a wind instrument,
for example) into an energy wave (the sound wave). This energy, or the sound wave, is the basis
for creating a sound.
In synthesizers, the basic waveform is generated by the oscillators.
Oscillators may be analog (VCO: Voltage Controlled Oscillator) or digital (DCO: Digitally Controlled
Oscillator, as in the case of the OB-12).
Oscillators normally generate three fundamental waveforms:
•
a sawtooth waveform (or ramp).
•
a triangular waveform;
•
a square waveform (or pulse);
Using a DCO it is easy to obtain a waveform, but the nature of the resulting sound is flat and
uninteresting. The waveform has an accuracy and constancy not found in the natural sounds
mankind is used to, including the sounds of acoustic instruments.
What’s more, if the aim is to create less real sounds, using simple waveforms does not guarantee
the generation of complex unnatural sounds.
In order to solve this problem, the OB-12 uses two oscillators (the first of them will be described
here) capable of generating three main totally configurable waveforms (as we have seen, they
are a sawtooth wave, a triangular wave and a square wave) which are then added together to
create a “sum” of the three initial waveforms.
The diagram in the next page will help you to understand this “combination” of waveforms: