I know you like ecology and DIY electronics! http://vperde.l29ah.blasux.ru/dump/0d256f3537e447e49e786365ae90e400/amp1.jpeg Here is my green efficient class D audio amplifier, 2*4.5W @ 0.2% THD. http://vperde.l29ah.blasux.ru/dump/a793088301457bf7ac4186f6b13c4481/amp2.jpeg The amplifier is based on TPA1517NE chip. Some of other electronic components are recycled, as are wires (ATX PSU cables, headphones cable), the casing (it used to be a box full of seaweed), the circuit board (some random pieces of cardboard) and the heatsink (a brass stopcock from an old soviet gas stove that i soldered with a gas burner). There used to be a 3.5mm jack input in the original design, but it didn't survive soldering apparently, so its only job is to attach the circuit board to the case. Bonus photo: http://vperde.l29ah.blasux.ru/dump/4e0197b4af2a153ecb495ca9fd815d1d/amp3.jpeg