Fostex HP-A4 BL, Headphone amplifier and DA converter, Up to 24 bits / 192 kHz, BurrBrown chip, Selectable digital filters, Frequency response: 20 - 80000 Hz (+/- 3dB @ 32 ohms / 100mW), Two-stage switchable basic reinforcement, Recommended load: 16 ohms to 600 ohms, DSD support up to 11.2 MHz, MicroSD card