Nonlinear System Identification for Guitar Amplifiers

Contact: A/Prof Paul Teal

Almost all electric guitarists believe that valve-based guitar amplifiers are superior to ``solid state'' amplifiers. This is because a guitar amplifier is designed to distort the sound signal from the amplifier, and produce all sorts of interesting and often pleasant (to some ears) effects. Many attempts have been made to replicate the sound of a valve amplifier with solid state components. These are largely been based on replicating some of the nonlinear behaviour of valves with solid state components. But there are a lot of interactions between the valves and the loudspeaker that contribute to the overall sound. Saturation of the output valve negates the feedback arrangements for instance, so the speaker is temporarily in a high impedance state.

This project involves taking measurements of an entire system including the preamp, amp, and loudspeaker, and then applying non-linear system theory to construct a system which is empirically identical. Anechoic facilities are available for performing these measurements.