Im trying to build a small solar powered boombox [currently i have a 4.8volt 3.4AH battery so a battery life estimate would be nice] i have 2 5 watt 8ohm speakers and a 30 watt 8ohm sub and i am trying to find a suitable amp to drive them from an mp3 player. Im looking for something as simple as possible without sacrificing sound quality. [also try to keep it under $20 ]
You could saw off apart the output amplifier section from an unwanted car radio with a hack saw, leaving the portion of printed circuit board near the output amplifier modules and a piece of chassis for heat sink. If it is a 4 channel, one could be used for the subwoofer and one spare. Look at the part number for the amplifier module and its data sheet will tell how to connect inputs and power.