When I was a kid, I had a little device I bought from radioshack that consisted of an amplifier and a magnetic pickup that could be stuck to the back of a telep

When I was a kid, I had a little device I bought from radioshack that consisted of an amplifier and a magnetic pickup that could be stuck to the back of a telephone handset to give you a speakerphone. I think I bought it because it was inexpensive and interesting, and boy how interesting it turned out to be! I discovered the pew-pew slinky sound and many others by playing around with that little thing.