ID3, no idea what that is. Yes, the files are native aif, created from direct CD rips on my old Mac via iTunes circa 2010 or so. I'll convert them all to flac if I absolutely must, but I'd really prefer not to. WiiM is supposed to be Mac-friendly out of the box, so I've been a bit surprised that aif support has been a moving target. It's not a deal-breaker, I really like the Amp.