The Moondrop MIAD 01 is one of the most distinctive Android devices of 2024 thus far. It has a 4.4mm headphone jack to go with the more conventional 3.5mm type. Furthermore, it seems it might be as appealing to teardown enthusiasts as well as audiophiles, and may, therefore, also be easier to repair than most modern smartphones.
This could end up competitive.
Invite people to your house, give them a tour and briefly mention the shelf before scurrying them on. Watch their faces contort but don’t give them the opportunity to ask any questions.
EDIT: I have a vague guess at what could have gone wrong with your adaptor. It might have had OK L and R contacts but a broken G contact. You would then hear the difference between the L and R channels, which most often sounds like garbage. Music would be weird (entire instruments/vocals disappear) and mono audio would be silent or near-silent (so you’ll have to turn it up a lot and will hear noise).