I think dac to cartridge is a pretty good analogy. Both make the last most meaningful conversion between information types (digital to analog; groove to analog electrical). Not a perfect analogy, but pretty darn good imo
the cartridge I suppose has a broader scope, converting a mechanical info source to electrical, whereas the dac just converts one form of electrical info to another, but in either case the last meaningful conversion
(yes I know the very last is electrical to sound waves by the speaker, haha)