Title:
Digital Circuit-Level Emulation of Transistor-Based Guitar Distortion Effects
Digital Circuit-Level Emulation of Transistor-Based Guitar Distortion Effects
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Authors
Overton, William Ernest
Advisors
Lanterman, Aaron D.
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Abstract
The objective of this thesis was to model the Fuzz Face , a transistor-based guitar distortion effect, digitally at the circuit level, and explore how changes in the discrete analog components change the digital model. The circuit was first simulated using SPICE simulation software. Typically outputs and how they changed based on transistor gains were documented. A test circuit was then constructed in lab to determine true transistor gains. An analog Fuzz Face circuit was then constructed, and physical parameters were recorded. A digital model was then created using MATLAB. Capacitive filtering effects were found to be negligible in terms of the guitar signal and were not modeled. The transistors were modeled using the Ebers-Moll equations. A MATLAB algorithm was written to produce Fuzz Face type distortion given an input guitar signal. The algorithm used numerical techniques to solve the nonlinear equations and stored them in a look-up table. This table was used to process the input clips. The sound of the Fuzz Face was not perfectly modeled, but the equations were found to provide a reasonable approximation of the circuit. Further study is needed to determine a more complete modeling equation for the circuit.
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Date Issued
2006-04-13
Extent
1437132 bytes
1437132 bytes
649175 bytes
327874 bytes
1437132 bytes
1437132 bytes
649175 bytes
327874 bytes
1437132 bytes
Resource Type
Text
Resource Subtype
Thesis