Virtual Analog Modeling of Guitar Amplifiers with Wiener-Hammerstein Models
* Presenting author
Virtual analog modeling of guitar amplifiers is an ongoing research topic and its aim is the recreation of an analog system as exactly as possible. A mathematical model can be created which can be used reproducibly and independently of aging hardware and temperature dependence. In this way the popular sound of vintage tube amplifiers can be combined with new digital recording techniques.In this work the reference system is characterized by measuring it. Accurately defined input signals are sent through the reference system and its reaction to these signals is analyzed. Wiener-Hammerstein models are used to recreate the characteristic sound of guitar amplifiers. Wiener-Hammerstein models consist of a series connection of an input filter (LTI), a nonlinear transfer-function and an output filter (LTI). Input and output filter of the model can be measured and calculated. The nonlinear transfer function between the filters is a parametric mapping function, mapping input amplitude to output amplitude according to a nonlinear function. The parameters of this function can be determined by iterative optimization algorithms. The proposed method yields convincing results if the parameters and optimization signals are chosen carefully. The results are verified by objective error measurements as well as a listening test.