4 GENERAL DESCRIPTION
Your MiniBrute is a true analog sound synthesizer, so all sounds are produced by
analog electronic circuits. No digital computer circuitry is involved in the
generation, filtering, or basic control of sound. This is one of the reasons why
MiniBrute creates rich, animated, and lively electronic sounds.
4.1 Analog synthesizer architecture
The analog sound production chain uses a classical approach called subtractive
synthesis. The basic sound generator is a waveform with a rich harmonic content;
filtering then “subtracts” harmonics to create new variations on the original timbre.
Subsequent circuits (an envelope generator in conjunction with a VCA, or voltage-
controller amplifier) alter the level in a precise way to create dynamics.
4.1.1 Signal generators
The signal generators are the circuits that produce the basic waveforms for sound
creation. There are two basic categories: pitched signal generators and the
unpitched signal generators.
4.1.1.1 Pitched signal generator (oscillators)
This device, also called an oscillator, produces an electronic signal characterized
by a repetitive, shaped pattern (called a waveform). The number of times this
pattern repeats in a second determines the signal’s frequency, which determines
its pitch. For example, a pattern that repeats every 2.27ms corresponds to a
fundamental frequency of 440 cycles per second, or 440 Hertz (a unit of
measurement for cycles per second named in honor of Heinrich Hertz, who first
demonstrated the existence of magnetic waves, and abbreviated Hz). This
frequency is associated with the pitch of middle
A
on a piano keyboard. In
general, oscillators will provide some or all of the following basic waveforms: sine
wave, triangular wave, sawtooth wave, square and pulse waves.
If these waveforms have the same frequency, then their pitch is equivalent.
However, different waveform shapes have different timbres. For example, the sine
wave sounds dark and plain, while the sawtooth wave sounds very bright. The
square wave sounds a bit like a clarinet and the pulse wave resembles an oboe.
Arturia MiniBrute User's Manual
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4 General description
