I'll defer to your expertise. I just know it sounded crummy and compressed, more noise than music. That was with Neutron Music Player. But when I used the Dragonfly, and USB Audio Player Pro, it sounded like proper music. I used the Klipsch X7i back then. With lesser headphones I couldn't tell how bad the S4 sounded. The X7 is super neutral and detailed, and it didn't take long before I bought the Dragonfly just so I could enjoy my music again. Now I'm on the AK120ii>Solar, for my mobile setup. Those worrisome days are far behind me.