On the Use of Volterra Series for Efficient Real-Time Simulations of Weakly Nonlinear Analog Audio Devices: Application to the Moog Ladder Filter

Thomas Hélie
DAFx-2006 - Montreal
In this paper, we show how the formalism of the Volterra series can be used to represent the nonlinear Moog ladder filter. The analog circuit is analyzed to produce a set of governing differential equations. The Volterra kernels of this system are solved from simple algebraic equations. They define an exact decomposition of the system. An identification procedure leads to structures composed of linear filters, sums and instantaneous products of signals. Finally, a discrete-time realization of the truncated series, which guarantees no aliasing, is performed.