Summary:

The purpose of this project was to fully design and fabricate a complete guitar amplifier that would be portable, convenient, and could be operated anywhere, even locations where AC power is not available.  A variety of components and conceptual designs were considered, and these were narrowed into one product design that was carried out in full, including the fabrication of a working prototype.  The final design features the use of two electrical circuit boards: a preamplifier circuit that accepts a standard guitar input, boosts this input to line level, and allows adjustment of tone and balance, and a power amplifier circuit that takes the preamplifier output and amplifies the signal in order to drive two 22-Watt speakers, one internal and one external.  The amplifier is powered by a 12-Volt rechargeable battery that allows at least 200 minutes of operation at maximum volume.  The prototype amplifier is housed in a sturdy, attractive, particleboard enclosure that allows for convenient portability and protection from environmental factors.  The final design was successful in meeting the requirements listed in the initial problem statement.  A variety of tests indicate that the prototype amplifier functions properly, meets all stated specifications, and has a powerful, high-quality sound.  Overall, this design project was highly effective in achieving the desired results.  The prototype design offers musicians an affordable amplifier that can be used for rehearsal or performance in a variety of outdoor environments where a conventional AC-powered amplifier cannot be used.  The convenience of battery power along with its lightweight and portable size make this the perfect amplifier for any guitarist.  A digital photograph of the working prototype is shown in the figure above.