This is a portable battery operated little amplifier I built to plug other portable things into and to also use it as a test amp for other projects. The circuit is based on a 5 Watt LM384 mono chip amp, taking a 1/8" stereo jack and resistor summing to a mono output. Giant volume knob, on/off rocker switch with power LED light. 4 Ohm, 6 Watt speaker pulled from an old Creative 5.1 set. Wooden enclosure with a custom designed speaker hole.