The FiiO Alpen 2 E17K is a compact portable USB and coaxial
digital to analog converter as well as an analog headphone amplifier for
driving your favorite headphones at work and on the road.
Using the unit's SA9027 USB receiver chip, the device can be used as an external sound card for computers with support for up to 96 kHz 32 bit files and DSD decoding (with ASIO driver and SACD plug-in). It features the Texas Instruments PCM5102 digital to analog converter for improved S/N ratio, lower distortion, and more linear digital-analog conversion characteristics than previous generations. It also uses Texas Instruments' flagship OPA1622 low-pass filter, and the OPA1642+LMH6643 chips in an OP+BUF architecture that is often found in higher-end conversion systems.
For I/O the unit features a Micro-USB socket for charging, data exchange, and the option of docking with future desktop products. It also features a coaxial digital input with support up to 192 kHz/24-bit PCM input (via the included 3.5mm to coaxial converter plug), as well as a dual-function line in / line out for maximum convenience.
Two front panel buttons allow you to power on the unit, navigate menus on the OLED display, select the input, and lock the device. All other controls such as bass adjustment, gain level, and volume control are provided by a side mounted multifunction control wheel. The device's internal rechargeable battery provides more than 15 hours of operation on an approximately 3 hour and 40 minute charge.