I’ve tested my headphones on an LE OLED and a 512 GB OLED and while it was present on both to the same degree, it was very quiet to the point of me questioning if it was even there. It is only really noticeable in a quiet room. It is not at all noticeable when game audio is playing, but is most prevalent in the menu of SteamOS. Some audio recordings I’ve heard makes it sounds like some of you are getting a haircut while wearing headphones, and I cannot get my phone’s microphone to pick up the sound at all.
Someone on the sub found a fix if you are interested https://www.reddit.com/r/SteamDeck/comments/188fxu1/fix_audio_cracklingstatic_on_35mm_headphone_jack/
I’ve seen it. If it was bad enough to actually be noticeable, I would probably just send it back for a refund. But it’s so quiet that I can’t tell if it’s there or not half of the time even in complete silence.