Hmm, seems like some phones don’t have a DAC anymore and thus, the USB-C adapter need to get the audio in digital form and use its own DAC…

I guess in that case, it would be a better experience attaching a wifi audio receiver and send the hifi signal over that. Best scenario would be if the music box would have a digital in port you can use, so you would use the DAC dedicated to your speakers, which is better than phone DAC in most cases.