The Astell&Kern A&norma SR15 aims to be a portable system for playback of high-res audio, utilizing dual Cirrus Logic CS43198 chips and supporting 24-bit/192 kHz bit-to-bit type playback. The 64GB of on-board storage can be expanded with a microSD card (up to 400GB, total). The device can also work as a preamp for digital audio over USB.
32-bit audio is down-sampled using a sample-rate converter, and DSD 64/128 can be played back through conversion to PCM. DSDNative, on the other hand, stays in the DSD world. The player sports 3.5mm, 3-pole unbalanced and 2.5mm, 4-pole balanced headphone jacks. The balanced output can remove noise (common mode noise) that can occur in signal and inverting amplifier signal, while offering increased power output due to its double transmitting of signals.
The player sports a quirky design with a screen diagonally inset against a rectangular backdrop for an idiosyncratic look. The volume wheel is designed to be protruding slightly from a concave surface so that you can control volume with a simple motion of sliding your finger up and down. With onboard quad-core CPU, the SR15 possesses more than enough power for playing digital music and powering the user interface.
The audio player supports USB audio digital out and allows you to connect diverse digital-input portable amps through USB. It can transfer DSD in native through DoP and convert 5.6 MHz DSD into PCM for output to portable amps that do not support DoP. External amplifiers can be connected to the device utilizing a separately available OTG cable. An aluminum body lends durability to the whole construction.