A portable amplifier is disclosed. In embodiments, the portable amplifier comprises a cabinet that opens and closes on a diagonal to contain all internal components, and optimizes sound quality. In embodiments the portable amplifier can be connected to an extension cabinet in order to provide an additional speaker. The portable amplifier can function on AC or DC power, and features user-friendly lighted ports and controls. The amplifier can feature AINiCo speakers and a three-spring reverb tank. The portable amplifier can be optimized for weight and power to achieve output of about 4 to about 5 watts per pound.