I’m looking at an old (early 20th century) hand-crank record player that was handed down to me from my great-grandmother. It’s a simple wooden box with a spring & flywheel mechanism that spins the turntable at a somewhat constant speed, a metal needle that rides in the grooves of a record disk and transmits the vibrations onto a small metal drum, and a big metal horn that focuses the sound from the drum and directs it out into the room. The power source is a human winding a spring. The sound and amplification are purely mechanical.
It’s simple. If it breaks you can take it apart, look at what’s inside, and with just a bit of tinkering you’ll probably get it to work again. If it somehow survives a few thousand years, the people from that era will look at it, figure out what is is supposed to do and with a bit of tinkering it’ll be made to work again. If one were to draw the mechanicals out on archival paper, a person from the future would be able to create a functioning replica using only late 19th/early 20th century technology.