i bought one fr lazada around $6.60 that says "oneplus type c to 3.5mm aux audio adapter..."
does the job and not soft like you mentioned
how about OP7?
frankly, the camera is kinda a hit and miss, like you fire 10 bullets and a few can hit the target only

so i need to take several shots then choose the best from the bunch which has the least non-blur and sharp pic
let's just say i prefer using my previous s7e (2016) and xr (2018). super easy to point-and-shoot quickly and get consistent images most of the time. op camera definitely needs a lot more improvement esp in the shutter speed which i'm not v fond of. however, i'm not a camera person so it doesn't impact me that much lol. just sometimes when i really need to take pic on rare occasions, it is a little hard to expect perfect shot with 1 snap