Astell & Kern SE300 Music Player

The Astell&Kern A&futura SE300 is the fourth A&futura player, the line that carries Astell&Kern’s most innovative ideas, and the first Astell&Kern player with an R-2R DAC and a Class A amplifier. Its fully discrete 24-bit R-2R DAC is built from 96 ultra-precision resistors, the amplifier switches between Class A and Class AB, an FPGA developed by Astell&Kern offers OS and NOS modes, and TERATON ALPHA ties it all together, for a natural, analogue sound from digital sources.

Fully discrete 24-bit R-2R DAC

To reproduce analogue sound better, Astell&Kern designed the DAC and amplifier together from the start. Instead of the delta-sigma DAC chip found in most players, the SE300 uses an R-2R, or ladder, DAC, with resistors arranged like the rungs of a ladder. R-2R sounds natural yet dynamic, but it is hard to build, needing complex, precise resistor networks and careful current control. After several years of development and much trial and error, Astell&Kern hand-picked each of the 96 ultra-precision resistors and finalised its design.

• True 24-bit decoding: 48 pairs (23 × R and 25 × 2R) of the 96 resistors create the analogue signal.
• 0.01% tolerance: an R-2R DAC needs current values summed from resistors with the smallest possible error, so every resistor was inspected to 0.01%.
• TCR10: to keep that precision as temperature changes, the resistors have a low temperature coefficient of 10ppm/°C.

Class A or Class AB

The dual amplifier lets you choose by taste or genre. Class A gives the most linear output, amplifying without distortion or loss for a soft, warm and natural sound; fed by the R-2R DAC’s refined analogue signal, it comes closest to the original analogue audio. Class AB is powerful and efficient, with dynamic, crisp sound and low harmonic distortion. Astell&Kern’s own designs reduce power consumption while raising output and removing noise.

Two gain levels, Normal and High, match sensitive IEMs and hard-to-drive headphones, with high current for powerful sound and driver control, and up to 6Vrms balanced for high-impedance headphones.

TERATON ALPHA

A Class A amplifier was thought impossible to miniaturise, and Astell&Kern says it could not have combined it with the precision R-2R DAC without TERATON ALPHA, its sound solution of effective power-noise removal, efficient power management, unwavering amplification and a fully converted output interface, here with current and temperature control and an optimised FPGA design.

FPGA with OS and NOS modes

Instead of an off-the-shelf chipset, the SE300 uses an FPGA (field programmable gate array) developed by Astell&Kern, whose algorithm passes the digital signal to the R-2R DAC. It offers two modes, designed for the SE300’s hardware and software. NOS (non-oversampling) plays the pure, unprocessed sound decoded by the R-2R DAC itself. OS (oversampling) adds partial digital processing that extends the bandwidth, for impressive detail, a wide sense of space and a crisp, clear sound.

Interface and features

The redesigned Crimson interface makes the SE300 a true music player: browse categories quickly, rediscover songs and search album art. Its keywords are edge, simplicity and dark mode, in black with red highlights that reduce visual fatigue, and app services, artist view and album sorting were improved. Streaming apps install from the Services menu. The 5.46-inch Full HD screen is large and vivid.

• LED wheel: a light behind the volume wheel, like rising waves, shows the bit depth of the track or the current amplifier mode, and can be switched off.
• DSD256 and 32-bit/384kHz playback, plus MQA files and streams.
• ReplayGain evens out volume across tracks (up to 24-bit/192kHz).
• AK File Drop transfers music wirelessly from a PC, phone or FTP program.
• BT Sink plays music from your phone through the SE300; Bluetooth 5.0 sends LDAC and aptX HD.

Design: Stream

The design concept is “Stream”: small ripples becoming crashing waves, for a player built around a Class A amplifier. The aluminium body has streamlined surfaces that suggest music flowing, contrasted with stainless steel and glass. The bottom curves outwards for a more ergonomic grip, and the polished stainless steel right side and the triangular-patterned volume wheel create a striking contrast; a straight pattern behind the wheel lets you see the volume change, and the hidden wheel light reflects off the side and the knurling. The rear glass has a new etched pattern of Astell&Kern “A” logos in different sizes and inclinations, adding depth and flow.

Good to know

• USB-C charges the player and connects it to a Windows 10/11 or Mac computer. Firmware updates over the air.
• In the box: SE300, USB-C cable, protective films, microSD slot cover and quick start guide.