Pretty neat and cheap project I put together last night with basic components. They call for an LM348, but I used an LM324 and it works fine. I enclosed it with some thin oak I had leftover from a different project and bent copper wire in the shape of the output waves to give it a cool retro look. I think it qualifies as EE desk art, yet it functions admirably!

You can check the schematic out here:

If you have any questions feel free to ask! Good luck.