I didn’t know what to expect from Cayin’s foray into IEMs. I had high hopes, but these things can go wrong in a million different ways. The worst possible outcome is for a product to be forgettable, to not stand out in any meaningful way. That is not Cayin’s fate, let me assure you. The YB04 stands tall indeed. From the soundstage, to the resolution, to that smooth, airy treble, the YB04 enthralls you with its unique voice and astonishing performance. Even if your personal tastes usually lie elsewhere, this monitor may have the charm to win you over.