Franzis 10187 mp3 amplifier kit franzis 9783645101875 the franzis mp3 amplifier kit lets you build your own loudspeaker for mp3 players and mobiles em without soldering a thing em clear step by step instructions are included as is the 3 5mm audio jack connector lead this unique kit makes the perfect fun gift for any music lover with their own mp3 player or smartphone includes all components and instructions in the shape of a classic haynes manual franzis 10187 mp3 amplifier kit