An Alchemical Feedbacking Echo Delay Effect.
The ancient symbol of the Ouroboros, a serpent devouring its own tail, has fascinated cultures for centuries. Representing the cyclical nature of life and eternity, this symbol resonates with deep meaning.
Alchemy, the ancient practice of transmutation and spiritual growth, sought to uncover the secrets of transformation. Similarly, feedback, a fundamental concept in various modern fields such as chaos theory and machine learning, involves the continuous loop of information exchange for improvement. Looking at sound and acoustics with the Ouroboros in mind, we may see the shape of the sine wave and so many higher level musical attributes as being Cycles, Circles, continuously emerging, combining, decaying and repeating. All together, these concepts form an intriguing set of connections, highlighting the interconnectedness of ancient wisdom - much of which took audible forms - and the most modern of technologies such as digital audio effects or the training of machine learning models - the latter literally represents the feeding of our collective written consciousness back at us, only to be re-ingested.
These ideas formed some of the inspiration for the iterational designs of the Ouroboros Succession effect. Here are some of the icons I designed with these concepts in mind. I meditated with Midjourney to generate fantastical illustrations on the themes, which I used to decorate the performance interface and Kyma iconography.
The Ouroboros, Kekulé's inspiration for the structure of benzene by Cristian Vogel
Double Ouroboros and all-seeing-eye by Pikisuperstar
One of the UI illustrations running in Kyma
Design Process
I started working on this processor in 2021, the news dominated by the vulgarity and violence of the 6th January Capitol attacks and the motivating forces behind them - hence the witty working title 'Succession Delay'. Perhaps in response to the destructivity of those events I focussed my creativity on the challenge of building a highly musical circulating delay line effect, which crucially - would not bend pitch when the length of the delay line is changed in realtime. Kyma already has a solid and reliable 'bendy' prototype in the standard library, indeed one of the Classes I use most of course. Its the DelayWithFeedback prototype Class, a mono, clean, interpolating delay line. It is a basic sample accurate buffer with feedback, but not a fully fledged echo pedal. When changes to the length of the cycle are not rate interpolated, then we hear glitches and zipper sound caused by discontinuities as the read or write buffer jumps. This is normal in a digital buffer, and a number of strategies have evolved to mitigate these artefacts. In order to get in there and build something more elaborate, if you want to build a custom circulating buffer effect, then you need to construct your own feedback network. In Kyma we do this using the FeedbackLoop prototypes from the standard library.
Kyma's FeedbackLoop and DelayWithFeedback Prototypes
I approached the challenge in a number of ways on and off over the next couple of years. My main design strategy was to instantiate a number of buffer 'cores' , offset them in time from each other and then trigger a rapid computed crossfade between them whenever the overall delay line length gets changed.
The Circular Path
I then went on to add a number of colour touches to the feedback paths internally. Especially nice is the NeverEngineLabs ZDF state variable filter and lowpass filters and the Kyma standard library saturation in the chain. Most of the published Ouroboros versions are very efficient in terms of DSP, and have a character all of their own. Perhaps my favourite version is the v1.4 from 2021. It is very efficient and has a number of cool features, such as an optional rate shifting in the feedback loop, so the circulating sounds can ladder up and down in speed as it repeats if so desired. This one got pushed back because although it was awesome the extra pitching buffer features were introducing a bit too much glitching artefacts. Nevertheless, it is included along with the rest of the highlights from the development cycle. Obviously, there is nothing stopping you from building even larger feedback networks by connecting their signals back into each other.
The Unbroken Circle
In summary, the relationship between the ancient symbolism of the Ouroboros - renewal, the continuous cyclical process of feedback resonates deeply in the fields of sound design and acoustics, particularly in the realm of echo delay audio effects. The echoes created by this richly featured effect mirror the cyclical and transformative nature of the Ouroboros, while the deliberate manipulation of feedback in the design allows for the creation of immersive sonic environments. By harnessing the power of feedback, sound designers and acousticians can shape and mould simplicity toward infinite complexity, transforming mere sound waves into captivating sonic journeys that transport and engage listeners on the profoundness of the ancient ways.