It sounds like there’s a little motorcycle riding around in my earbuds. The frequency changes with the brightness of the screen. I play 100% with headphones so I have to return it, but if they all (or a significant percentage) of OLED units have this problem then I’ll just return it and not get another one right now.
Edit: it’s good to hear that not everyone has this problem. I’d be curious for those people who aren’t having the problem to test with a bright white screen. Mine gets worse as the brightness of the screen increases.
Edit 2: I used a MillSO 1/4” to 3.5mm adapter and my Sennheiser HD558s and I can’t hear the buzzing like I can with my Apple earbuds.
Try different headphones, seems like lower impedance headphones (e.g. most earphones) pick up the interference.
I tried with 16 ohm earbuds and 28 ohm headset, it was very noticeable with the earbuds but I literally can’t hear it at all with the headset.