Project
| # | Title | Team Members | TA | Documents | Sponsor |
|---|---|---|---|---|---|
| 28 | Synth + Guitar Multivoicer Pedal using DSP |
Danielle Lange Ishan Jain Madhav Khirwar |
Feiyu Zhang | design_document1.pdf design_document2.pdf design_document4.pdf design_document5.pdf final_paper2.pdf final_paper3.pdf other1.pdf presentation1.pptx |
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| # Problem: A lot of guitarists these days, especially in the metal/indie scene use an extensive set of guitar pedal effects to shape their guitar tone. However, analog pedals are often prohibitively expensive to have many of. There exist digital solutions and pedal boards, with the limitation that they are often really expensive ($600+). A lot of the effects that are implemented digitally try to mimic analog guitar tones, instead of exploring the vast artistic possibilities that digital signal processing offers # Solution: Our solution is to use an ATMEGA328P Processor to implement a novel kind of guitar pedal – one that will add electronic harmonies to an analog guitar note played by the guitarist. This will be in the form factor of a normal pedal, and the knobs will give the guitarist the option to select what kinds of harmonies they want to overlay (Major 5th, Major triad, 7th, etc). This will result in a single solution for a sound that indie/rock guitarists often try to recreate with much wasted effort # Input/Output subsystem: The input subsystem will be all analog, and will allow the user to choose the input gain, and will use low pass filters to cut off unwanted high harmonics that may cause aliasing in ADC. The output from the Arduino will be low pass filtered and will use parallel PWM signals to improve the resolution. # DSP Subsystem: The digitized input will be analysed for it’s fundamental frequency. When the fundamental frequency is analysed, the input note will be mapped to the closest note according to the standard 440Hz ‘A’ note and the 12-tone equal temperament system. This note will then be used to calculate the notes of the selected harmony, and the harmony notes will be synthesized with a DSP waveform generator chip such as AD9835 and be balanced output along with the guitar signal. # Criteria for success: We would consider this project successful if the system outputs a signal which has a balance between the played note and synthesized notes, and is the size of a normal guitar pedal such that it can fit on a guitarist’s pedal board. As a guitarist myself, I often record guitar parts and then go back and double those melodies with a synth manually, and this would save a lot of time as well as open up a range of creative possibilities. |
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