ECE Course Outline
Guitar Amplification and Effects
(ECE 3043 [min C] or ECE 3741 [min C]) and ECE 3084 [min C]
Mathematical analysis and laboratory measurement of vibrating strings, electromagnetic pickups, vacuum tube amplifiers, solid-state distortion and swept filter effects, and loudspeakers.
No textbook specified.
Historical perspective Acoustics of vibrating strings The 1-D wave equation Interpretation of pluck as initial condition Traveling waves Electromagnetic pickups Physical principles Linear circuit models Effect of location High voltage safety procedures Vacuum tube properties Electrodynamic principles Small-signal and large-signal models Vacuum tube amplifiers Biasing, gain, input/output impedance, frequency response Distortion characteristics Solid-state distortion effects Germanium vs. silicon BJTs Overdriven transistor amplifiers Diode-based waveshaping circuits Swept filter effects "Wah" pedals Allpass filters and "phaser" effects FETs as variable resistors Bucket-brigade devices and "flanger" effects Loudspeaker modeling
Objective: This class explores the fields of acoustics, electromagnetics, electronic circuits, device physics, and signal and system theory and through the specific platform of the electric guitar and its commonly associated amplifiers and effects devices. The distinction between these tools begins to break down, since amplifiers are often deliberately driven to distortion as an effect, and in the hands of a skilled and thoughful player, the various effects pedals musicians often employ may be better thought of as part of the complete “instrument.” The guitars, amplifiers, and effects explored in this course are not just intriguing motivational examples for traditional ECE topics; we feel that they are technological and cultural artifacts worthy of study in their own right in the spectrum of systematic musicology. They are part of our history. We believe that Jimi Hendrix, wrestling his Fuzz-Faced Stratocaster in front of his Marshall amplifier stack, was a transcendent example of a cyberphysical system — a beautifully unstable feedback loop of sweat, circuitry, and sound.