Building a Simple Amplifier
2007-10-01 13:34 - General
So, my dad is involved in something akin to square dancing. For either practice or general entertainment, he'd like to have a copy of the music, with the caller's instructions to listen to on his own time. So, he went out and bought a portable mp3 player (without consulting me, his first mistake!). It advertised the ability to record things as well as play them, which was exactly what he wanted. Alas, it had only a line-in jack, and a microphone did nothing. So he contacted me!
We're both frugal people, I got it from my parents, so I understood immediately when he wanted to build a preamp to go between the microphone and the recorder. Of course, he doesn't even own a soldering iron, much less the skill to handle the rest of the process. It was a fun little project to get into, so I agreed to take it on for him. I did the responsible thing, and started with a breadboard, the first picture above. I skipped that last time I built something like this, and it never worked. Next step, to the left, was the dirty perf board. I had as little assembly done as possible to have it still resemble the final version, and it still worked!
I took some special care with this project. It ended up in the box you see to the left. It was the nice little version that incorporated a battery door, perfect for this project, and convenient to boot. I was very happy with the results, with just one caveat: I "machined" the thing by hand, so the holes I drilled to mount the components (power switch, power light, input and output) ended up all crooked instead of in a nice line. Such a shame, because otherwise it's so nice!
