It’s not shielded properly, so the surrounding electronics cause crackles, buzzing and similar noise. AFAIK this was the case for all OLED models on launch. Might be fixed for newer ones, I’m not sure. Apparently it can be fixed by opening the Deck and sticking on some eletric insulation tape.

I mostly use the built-in speakers. Sometimes my IEMs, using a USB-C dongle as my OLED’s headphone jack is pretty noisy (I know it’s easy to fix, but I haven’t gotten around to it yet).