Explore the spectrum of virtual analog modelling techniques in this conference talk from the Audio Developer Conference. Delve into traditional methods like modified nodal analysis and wave digital filters, single-architecture neural network models, and grey-box methods combining physical modelling with machine learning. Examine several models of the Boss DS-1 guitar pedal's gain stage as a practical example. Learn how these methods can be applied to a wide range of circuits and understand the specific challenges associated with each modelling technique for different circuit types. Gain insights from Christopher Johann Clarke, a PhD candidate specializing in multiphysics and AI/machine learning, and Jatin Chowdhury, an experienced audio signal processing engineer and CCRMA graduate.