A Review of Digital Techniques for Modeling Vacuum-Tube Guitar Amplifiers

摘要

Digital emulation of guitar tube amplifiers is a vibrant area of research with many existing commercial products. Linear parts of the amplifier, such as the tone stack, are modeled using digital rnfilters, for which the parameters are found with system-identification methods or by using a priori knowledge of the underlying circuitry. In the simplest case, the distortion introduced by the tube stages is modeled using static waveshaping. Aliasing problems can be avoided using oversampling. More-sophisticated methods can be used for the simulation of dynamic nonlinearities. Most of these methods can be classified as being inspired by circuit signal paths, which try to model the signal path from the amplifier's input to the output. There are also some methods that attempt to simulate the operation of the underlying electric circuit, but these are often either greatly simplified or still too demanding computationally for real-time modeling of complex circuits. Alternatively, some analytical methods, such as Volterra series or dynamical convolution, have also been suggested.