Download Nonlinear Circuit Simulation using Time‐Variant Filter The dynamic simulation of nonlinear guitar effects has recently been studied in depth. There are several approaches to the simulation of the distortion guitar effects. This paper presents an algorithm based on using a digital linear time-variant filter for the simulation of the nonlinear circuit of diode limiter. Filter coefficients are changed in each sample period according to the level of an input and output signal using numerical methods for the solution of nonlinear functions. The designed algorithm was used in the distortion effect to examine its characteristics. Sound examples of the implemented distortion effect can be found at web page www.utko.feec.vutbr.cz/~schimmel/DAFx09/.
Download Real-Time Guitar Tube Amplifier Simulation using an Approximation of Differential Equations Digital simulation of guitar tube amplifiers is still an opened topic. The efficient implementation of several parts of the guitar amplifier is presented in this paper. This implementation is based on the pre-computation of the solution of the nonlinear differential system and further approximation of the solution. It reduces the computational complexity while the accuracy is comparable with the numerical solution. The method is used for simulation of different parts of the guitar amplifier, namely a triode preamp stage, a phase splitter and a push-pull amplifier. Finally, the results and comparison with other methods are discussed.
Download Simulation of a Vacuum-Tube Push-Pull Guitar Power Amplifier Power amplifiers play an important role in producing of guitar sound. Therefore, the modeling of guitar amplifiers must also include a power amplifier. In this paper, a push-pull guitar tube power amplifier, including an output transformer and influence of a loudspeaker, is simulated in different levels of complexity in order to find a simplified model of an amplifier with regards to accuracy and computational efficiency.
Download Simulation of Fender Type Guitar Preamp using Approximation and State-Space Model This paper deals with usage of approximations for simulation of more complex audio circuits. A Fender type guitar preamp was chosen as a case study. This circuit contains two tubes and thus four nonlinear functions as well as it is a parametric circuit because of an integrated tone stack. A state-space approach was used for simulation and further, precomputed solution is approximated using nonuniform cubic splines.
Download Guitar Preamp Simulation Using Connection Currents This paper deals with a method of decomposition of a nonlinear audio circuit based on so called connection currents. These currents are used to connect inner blocks of the audio circuit with regards to preserve mutual interaction between adjoined blocks. Although this approach requires usage of numerical algorithm to solve the nonlinear equations, it reduces number of nonlinear equations to be solved if the solution of inner blocks is approximated while the accuracy of simulation is comparable to numerical solution of the whole nonlinear audio circuit.