Building on some of the same basic principles that eventually gave way to the cassette recorder, this kit lets you transcribe the sound of your voice into magnetic charges and play them back with a swipe of your hand.
Inspired by the 19th-century designs of Valdemar Poulsen’s wire recorder, this kit from Gakken Japan looks like it could be fun to play with. Once you put it together, you set the recording head on top of any metal surface that will hold a magnetic charge, drag the control across the surface and speak into the microphone. You can use anything from a metal tabletop to a common kitchen knife to store your secret messages. Once recorded, flip the playback switch and you’ll hear your scratchy voice played back as you move the magnetic head. The video below shows how it works. Feel free to jump ahead to around 50 seconds in to get to the interesting bits.
Keep in mind that the instructions for assembling this kit are entirely in Japanese. But they do seem to have enough visual detail that you should be able to build the wire recorder successfully. Want one? You can order the wire recorder kit over at the Maker Shed for $38.99 (USD). Just don’t try putting this anywhere near your old VHS tape collection.