This weekend I assembled a very cool Tripath amplifier. These amps come as a kit (a printed circuit board and some components), and you have to solder them together. The end result is something pretty tiny (about the size of an iPod), but with amazingly big sound. More specifically, you can drive a pair of 25w speakers off 8 AA batteries and easily overload them! It's pretty amazing to watch. The sound is crystal clear, and it's hard to believe that it can come out of something that small.
My friend and I each assembled one such amp. He wants to use it to put a stereo on his bike: he's built a carboard enclosure that houses two speakers and sits in the frame of the bike. The sound that comes out of that cardboard enclosure is just amazing, I think he can easily wake up the neighborhood. I have more mundane plans for my amp: I just want to drive two speakers in the house, for music and projecting movies. For that purpose, I also built a small enclosure for the amp, basically a cheap plastic box with some carefully drilled holes. It's got a distinct home-brew feel to it, and I just think it's great.
I used to love building stuff like this when I was little, and even after all these years, I still think it's all that.
