Yep, I'm with you. I use Shure SE846 earbuds, and even though the dongle supposedly uses a DAC chip identical to the DAC in the iPhone 6, the audio is noticeably flatter and less enjoyable. Since the chip is the same, I figure it must be either the amplifier (haven't read whether that's the same) or the bit of super thin cable between the chip and the headphone port. It was a downgrade from the iPhone 6.