The Nonlinearcircuits Fourier Eurorack module, an intriguing intersection of Fourier synthesis and a Walsh subset, rewards its users with mesmerizing soundscapes and enigmatic drone outputs. Born of an imperfect, yet fascinating idea by E. Muller, it wraps its imperfection around a core of mathematical harmony which results in a delightful aural surprise.
Embracing an unconventionality, it possesses control pots for 7 sine and 8 cosine signals- an approximate representation of the harmonics of the initial signals. Take this notion of 'approximate' lightly, for the output waves are not pure sinewaves, but stepped pulse waves imbuing a peculiar sonic charm to their outputs.
In terms of utility, the Nonlinearcircuits Fourier needs to be patched into a low pass filter (VCF) to arrive at its standard function. Do take these restrictions as artistic suggestions rather than rules. Patch it differently, feed it a different diet of signals, and witness it bloom into an unconventional marvel. The module doesn't feature a built VCF, considering its common presence in a standard Eurorack case.
The module thrives on a fast clock signal stemming from a VCO—16 times faster than the perceived audio output. This clock signal is processed by a multiplexer (also lovingly referred to as 'mux'), scanning through the channels and forwarding the signals to the output.
The existence of two independent MUX channels offers flexibility. The second channel is fed a clock signal at half the rate of the first one when on default setting. However, each channel being separately accessible broadens the sonic possibilities; a pot is provided to adjust the channel 2 level. When not utilized as a sub-harmonic source, an external signal can be mixed with channel 2.
Now this module isn’t merely limited to creating drone noises or modulating sounds; employing a slow clock signal paves the way for a slightly eccentric sequence or pattern generator. Individual reset and direction inputs are featured on each channel, enabling you to tweak and distort the proceedings as your creativity dictates.
Each pot's connection to multiple channels for harmonic creation bears the potential of treating your ears to a distinct sonic brew with each tweak. Take note, the pots plugged between +/-12V cut out when an external signal is patched, reducing their role to preset knobs, or in some cases, dormant dots on a board.
Inviting variety, this module extensively rewards experimentation with CVs in the harmonic inputs. Slow ones from Sloths or LFOs are quite the joy. Further exhilaration awaits when using white noise, and utilizing it as a clock source fuels an exciting exploration in sound.
The Nonlinearcircuits Fourier Eurorack module is an unusual, yet irresistible tool for adventurous sound explorers. It takes delight in bending the conventional, bathing in the unpredictable, and above all, generating sounds and sequences that are as fascinating as its underlying concept. This eccentricity is its allure, making it a staple for Eurorack enthusiasts yearning for sonic experimentation steeped in mathematical chaos.
Example Usage
NOVICE USAGE EXAMPLE:
To start exploring the captivating sounds of the Nonlinearcircuits Fourier Eurorack module, begin by patching it into a low pass filter, which can be any VCF you have in your case. This will allow for normal use and a more controlled output.
Next, you'll need a fast clock signal from a VCO. The clock signal should be about 16 times faster than the desired sound. Connect this clock signal to the module's multiplexor (MUX), which scans through the different channels and feeds the signal to the output. There are two MUX available, and they can be operated independently. Keep in mind that channel 2 will receive a clock signal half the rate of channel 1.
You can choose to use the individual outputs of channels 1 and 2 or mix them together using the module's built-in mixer. If you decide to mix the channels, you can adjust the level of channel 2 with a potentiometer. This allows channel 2 to act as a sub-harmonic source. Alternatively, you can replace channel 2 with an external signal for even more experimentation.
The module can also be used as a peculiar sequencer or pattern generator by feeding it a slow clock signal. This will yield intriguing rhythmic patterns and sequences that are sure to inspire your creative process. Feel free to explore different reset and direction inputs for each channel to further manipulate the soundscape.
To truly unlock the module's potential, try patching CV signals into the harmonic inputs. Slow CV signals from Sloths or LFOs work particularly well, as they add dynamic movement to the harmonics. Don't be afraid to experiment with audio signals or even use white noise, as they can produce interesting and unique results. In fact, using white noise as a clock source can lead to even more experimental sounds.
With the Nonlinearcircuits Fourier module, you have a powerful tool at your disposal for crafting otherworldly shifting soundscapes and mesmerizing drones. Its imperfect yet intriguing design offers a realm of sonic possibilities, waiting to be explored. So dive in, let your creativity run wild, and immerse yourself in the captivating world of the Nonlinearcircuits Fourier Eurorack module.
Here is an intermediate-level usage example for the article:
One fascinating way to explore the sonic capabilities of the Nonlinearcircuits Fourier Eurorack module is by using it as a unique sequencer/pattern generator. To do this, instead of the typical fast clock signal from a VCO, feed it with a slow clock signal. This slower clock rate will result in the module stepping through its channels at a leisurely pace, creating interesting and somewhat unusual patterns.
To further enhance the sequencing capabilities, take advantage of the reset and direction inputs of each channel. By patching varying CV signals into these inputs, you can dynamically manipulate the sequencing behavior, introducing unexpected changes and variations to the patterns being generated.
For instance, try patching slow and evolving CV signals from modules like Sloths or LFOs into the harmonic inputs of different channels. This will generate intricate rhythmic patterns that evolve over time, adding depth and complexity to your compositions. Experiment further by introducing audio signals or even white noise into the harmonic inputs and observe how it affects the generated sequences.
Furthermore, don't hesitate to mix and match the outputs of different channels. Blend individual channel outputs together and adjust the channel 2 level potentiometer to introduce sub-harmonic elements into the overall output. Alternatively, you can replace channel 2 with an external signal of your choice, allowing for even more sonic exploration.
Using the Fourier module as a sequencing tool opens up a world of possibilities and sonic experiments. Whether you're crafting evolving soundscapes or generating intricate rhythmic patterns, this unconventional approach will surely inspire your creativity and push the boundaries of your musical exploration. Give it a try and let your compositions take a unique and otherworldly turn.
Further Thoughts
Expert-level usage example:
In this example, we will explore how the Nonlinearcircuits Fourier Eurorack module can create unique and otherworldly sounds by patching in external signals and using slow CV inputs.
To begin, let's connect the Fourier module to a low pass filter (VCF). This will shape the output and give us more control over the sound. If you don't have a VCF installed, you can still experiment with other processing modules to achieve different results.
Next, we'll need a fast clock signal from a VCO to drive the module. Set the VCO's frequency to be 16 times faster than the desired output. This clock signal will be fed into the module's multiplexor (MUX). The MUX will scan through the channels and send the selected signal to the output.
Each channel of the Fourier module produces a stepped pulse wave, rather than a pure sine wave. This is where the uniqueness of the module shines. By patching in different CV signals into the harmonic inputs, such as slow CVs from Sloths or LFOs, we can create evolving and shifting soundscapes. Experiment with different CV sources and observe the impact on the harmonics generated by the module.
You can also get creative by using audio signals or white noise as input sources. The Fourier module will process these signals and generate complex and intriguing timbres. For an even more experimental approach, try using white noise as a clock source. This will result in unexpected and fascinating rhythmic patterns.
To add further control and variation to your exploration, take advantage of the reset and direction inputs for each channel. These inputs allow you to introduce abrupt changes or reverse the scanning direction of the MUX, adding an element of unpredictability to your sound design.
Remember that the pots (or inputs) on the module are wired as presets or nothing when an external signal is patched in. They do not function as attenuators. However, you can still use them to set initial levels or manually adjust the channel 2 level, which acts as a sub-harmonic source.
By harnessing the power of the Nonlinearcircuits Fourier module and experimenting with different input sources, clocks, and CV modulation, you can delve into a sonic world filled with captivating and otherworldly sounds. Let your creativity flow and enjoy the journey of exploring the limitless possibilities offered by this remarkable Eurorack module.
Make sure to check out the original article by E. Muller in the "Ejektor" section of Jan 1983 Elektor for a detailed description and further inspiration. Happy sonic explorations!