Creating a portable MP3 player three-band graphic equalizer and amplifier for a circuits laboratory final project

At George Fox University, all engineering students are required to take the sophomore level circuits course. In an effort to more effectively engage the students in the course, a new final project was designed to leverage the interest in music and audio that is shared by undergraduate students. This paper details the design and implementation of a battery powered, three-band graphic equalizer and amplifier for a portable MP3 player or IPOD and the associated labs and project that accompany it. There are three circuit design elements of the final project, the first teaching students how to use comparators to create a graphic display, the second detailing active filters, and the final lab describing peak rectifiers and the mixer that ties everything together. As a final project experience, each student is given a kit containing a PCB, a speaker, an on/off switch, a battery- holder, and every electronic component required to construct the final system. Students are also required to write a major lab report detailing the operation of the final project. After providing the experience one time, student engagement was noticeably higher, the results of the final project being significantly beyond the expectations of the course instructors.