Download Modelling digital musical effects for signal processors, based on real effect manifestation analysis For quite some time in the area of commercial utilization of digital audio effects, efforts have emerged to create simulate by software analog effects and effect processors This paper deals with the analysis of musical effects, the design of algorithms for simulating these effects, and their realization on both digital signal processors and the PC platform in the form of plug-in modules for the DirectX environment. It also deals with the problem of controlling the effect parameters and with subjective testing of algorithms, and it examines the fidelity of simulated effects as compared with the original.
Download Optimizing Digital Musical Effect Implementation For Harvard DSP Architecture In the area of digital musical effect implementation, attention has lately been focused on computer workstations designed for digital processing of sound (DAW – Digital Audio Workstation), which perform all operations with audio signals, such as routing, mixing, editing, effect processing, recording, coding, etc. They are in fact a combination of a powerful computer program and hardware cards with digital signal processors. Most of these operations, except editing, must be performed in real time. Until recently, all real-time operations were performed on digital signal processors. Thanks to the power enhancement of personal computer core, performing these operations in the CPU is currently possible. However, in most cases, digital signal processors are still used for these purposes because digital musical effect modelling is more effective and more precise with the digital signal processor. In addition to this, processing in digital signal processor saves the CPU computing power for other functions. This paper deals with optimizing algorithms of digital musical effects for DAW systems.
Download Digital Synthesis By Plug-In Method In Java Media Framework Environment This paper deals with the implementation of real-time digital musical sound synthesizers by the Plug-In method in the Sun Microsystems Java Media Framework environment. This environment use the Plug-In technology as well as the DirectX or VST environments, but the implementation methods are different.
Download Optimizing Digital Musical Effect Implementation for Multiple Processor DSP Systems In the area of digital musical effect implementation, attention has lately been focused on computer workstations designed for digital processing of sound, which perform all operations with audio signals in real time. They are in fact a combination of powerful computer program and hardware cards with digital signal processors. Thanks to the power enhancement of personal computer core, performing these operations in the CPU is currently possible. However, in most cases, digital signal processors are still used for these purposes because digital musical effect modelling is more effective and more precise with the digital signal processor. In addition to this, processing in digital signal processor saves the CPU computing power for other functions.
Download Using nonlinear amplifier simulation in dynamic range controllers Amplifying devices where the gain is automatically controlled by the level of the input signal performs dynamics processing. Non-linear components simulating tube amplifiers can be used in these devices to make musical signal audibly dense [1]. This paper deals with the simulation of tube amplifiers using the power polynomial approximation of transfer characteristic and their use in dynamic range controllers. The influence of various non-linear amplifying devices simulating tube amplifiers on the output signal spectrum of dynamic effects is presented as well.
Download Characteristics of Broken-Line Approximation and Its Use in Distortion Audio Effects This paper deals with an analytic solution of spectrum changes in scalar non-linear discrete systems without memory, whose transfer characteristics can be approximated via broken-line function. The paper also deals with relations between the harmonics ratio and the approximation parameters. Furthermore, the dependence of the harmonics ratio on the amplitude of a harmonic input signal is presented for the most common characteristics that are approximated via broken-line function. These characteristics are judged from the dissonance point of view.
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.