It follows the basic principles of Fourier Synthesis, and being able potentially to design your own waveforms. There aren't many modules that do additive & Fourier synthesis so I'm looking forward to finish this.
The pots (or inputs) allow control of 7 sine (s1-s7) and 8 cosine (C1-C8) signals...... supposedly
being harmonics of the initial signals. “Supposedly” because, the waves
are not pure sinewaves, rather stepped pulse waves.
This module would be well paired with a oscilloscope so you could see the waveforms that you sculpt.
Andrew also reckons that this module needs to be patched into a low pass filter.
BTW this Elektor magazine is a great resource of info.
"the process of decomposing a function into oscillatory components is often called Fourier analysis, while the operation of rebuilding the function from these pieces is known as Fourier synthesis." Wikipedia.
Fourier synthesis is the process of building a particular wave shape by adding sine and cosine waves.
The module follows the basic principles of Fourier Synthesis, with the pots (or inputs) allowing
control of 7 sine and 8 cosine signals. These are supposedly the harmonics of the initial signal. “Supposedly” because, the waves are not pure sinewaves, rather stepped pulse waves.
This synthesis technique is also called additive synthesis.
You can use it for Fourier Synthesis or as a sequencer/pattern generator.
If you are into shifting soundscapes and drones, this is a great tool.
Additive synthesis is a method of sound synthesis that builds complex sounds by adding together multiple sine waves with different frequencies, amplitudes, and phases. In other words, it involves combining simple waveforms to create more intricate and varied sounds.
In it's early forms, this was really primitive, but these early synths were the building blocks of wavetables.
The pic below is that of Jean Fourier who's experiments led to Fourier & Harmonic analysis.
The fundamental concept behind additive synthesis is that any periodic waveform can be represented as the sum of individual sine waves at different frequencies and amplitudes.
You can break down every single Hz to a sine wave.
Each sine wave in this additive process is called a partial, and the combination of these partials produces the final, composite sound.
So this idea is to generate the final sound by combining sinewaves (which are generated either manually or with algorithms)
The parameters that define each partial include:
Frequency: Determines the pitch of the partial.
Amplitude: Controls the volume or intensity of the partial.
Phase: Specifies the starting point of the sine wave.
The advantage of additive synthesis is its ability to create a wide variety of complex sounds, including those with rich harmonic content. However, the drawback is that manually adjusting the parameters of numerous partials can be labor-intensive. Digital technology has made additive synthesis more practical, allowing synthesizers and software to handle the complexities of manipulating multiple partials in real-time.
Additive synthesis contrasts with subtractive synthesis, where complex waveforms are created by filtering and modifying simpler waveforms (e.g., sawtooth or square waves). Each method has its strengths and weaknesses, and they are often used in combination to achieve a broader range of sound possibilities.
11. OSCar - Subtractive synth with the bonus of programmable additive waveforms. (1983)
These synths are all really rare & difficult to find.
But don't fear. There are a few software synths you can try
1. Native Instruments Razor: A software synthesizer that combines additive synthesis with traditional subtractive synthesis.
2. Air Loom II - modular additive synthesizer with a shape-shifting Morph Pad
3. Arturia Pigments 3
4. Arturia Synclavier V
The more I dug, the more additive synths I discovered, esp in the digital world.
A note about the Buchla 148 module. .. this is not a pure additive synthesis module but I thought
it deserved a mention. It generates a fundamental and its first nine harmonics (harmonic numbers 1 - 10). There is a modern eurorack version ... The Verbos Harmonic Oscillator
Other additive oscillators worth exploring are the Odessa from XAOC Devices and the Ensemble Oscillator by 4MS.
The OSCar is an interesting synth. (mine is in repair, but when Ive got it fixed I'll def do some demo videos).
"In addition to all the standard subtractive features that are common on analog synths of the day,
it has a bonus of programmable additive waveforms. Chris came up with a very creative way of allowing users to build their own waveforms by adding individual harmonics.
The top two octaves of the keyboard have their keys numbered from 1 to 24. When one of these keys is pressed in harmonic‑creation mode, it adds the harmonic of that number into the waveform in real time.
You actually hear the harmonic come in to the waveform as you press the key, which was unprecedented back in the early '80s. Pressing a key repeatedly increases the volume of that harmonic proportionally in the overall result.
The method produced additive waveforms very quickly, unlike all the additive systems which had preceded it, and meant that untutored users could be making their own waveforms in seconds." SOS magazine 1999
Shoot me a message if there is a additive synth you think I must include in this list.
