Astell&Kern’s new SEM4 DAC module for the A&futura SE180 music player features upsampling technology for an enhanced sonic performance

Astell&Kern, the global leader in premium portable high-resolution audio devices, introduces the SEM4 DAC module for its award-winning A&futura SE180 digital audio player (DAP). The fourth module in the series, this dual-DAC is the first to feature Digital Audio Remaster (DAR) upsampling technology, enhancing the sample rate of the audio source so music fans can get closer to the analogue-like original sound.

The A&futura SE180, an IF Design Award Winner 2022 and the first Astell&Kern player to boast interchangeable all-in-one DAC modules, allows music fans to customise their sound with different audio-flavoured DACs to find the hi-fi-grade sonics that suit them.

Astell&Kern SEM4 DAC module key features at a glance:

  • Equipped with an Asahi Kasei AK4493SEQ dual DAC for more natural playback
  • Specially developed Digital Audio Remaster (DAR) upsampling technology enhances sample rate and sound quality up to a maximum PCM rate of 384 kHz/DSD256
  • Features proprietary TERATON ALPHA Sound Solution technology
  • Supports play of up to 32-bit 768 kHz/Native DSD512 high-resolution digital audio files
  • Low-power consumption design provides 14 hours of playback

Introducing Digital Audio Remaster (DAR)

Specially developed for the SEM4, DAR upsamples the sound source up to a maximum PCM sample rate of 384 kHz/DSD256. Whatever file you are playing, the SEM4 will convert to a higher sample rate that suits the source. The result will be a more refined and richer sonic performance, revealing detail and nuances in your favourite music otherwise unheard.

The SEM4 Digital Audio Remaster upsampling guide:

Maximum upsampling PCM rate:

  • 44.1kHz range PCM will be converted to 352.8kHz for playback
  • 48kHz range PCM will be converted to 384kHz for playback
  • No conversion will be made when playing DSD with this option selected

Maximum DSD upsampling rate:

  • PCM files lower than 96kHz will be converted to DSD128 for playback 
  • PCM files over 96kHz will be converted to DSD256 for playback 
  • DSD files below DSD256 will be converted to DSD256 for playback with this option selected

Asahi Kasei AK4493SEQ dual DAC with VELVET SOUND™  

The SEM4 is the first Astell&Kern product to be equipped with a premium dual AK4493SEQ DAC from Asahi Kasei. Featuring VELVET SOUND™ technology, this DAC aims to deliver a more natural audio with even lower noise and distortion, along with a wider dynamic range. Carefully selected advanced switch and capacitor components allows the low-power consumption design to provide a stunning low-noise playback performance of up to 14 hours – the longest among SE180 modules.

SEM4 featuring TERATON ALPHA technology

The result of extensive research and development, Astell&Kern’s patented TERATON ALPHA Sound Solution is designed to deliver audio playback close to the original sound.  It effectively removes power noise and provides efficient power consumption and amplification right through to the audio output interface stage where the digital-to-analogue signal conversion (DAC) takes place – audio technology Astell&Kern has consistently developed and perfected over the years.

Meet the Astell&Kern A&futura SE180 DAC Module Family

The SEM4 is the fourth in a series of DAC modules exclusively designed for the premium Astell&Kern A&futura SE180 portable digital audio player. Each DAC module offers different sonic characteristics to suit the music you love. All modules support 2.5mm, 3.5mm and 4.4mm headphones connections for accommodating a greater variety of headphones and in-ear monitors (IEM)

  • SEM1 ESS ES9038PRO (supplied with the SE180 player)
  • SEM2 Asahi Kasei AK4497EQ Dual DAC
  • SEM3 ESS ES9038Q2M Quad DAC
  • SEM4 Asahi Kasei AK4493SEQ Dual DAC

The optional Astell&Kern SEM4 DAC (Asahi Kasei AK4493SEQ Dual DAC Module) is priced £369 / $400 / €429 and will be available from May from

The Astell&Kern A&futura SE180 (with SEM1 ESS ES9038PRO DAC module) is priced £1,399 / $1,499 / €1,599 and is available now from

Technical Specifications

Body Material: Aluminum, Stainless Steel, Polycarbonate

Body Colour: Moon Silver

Sample Rate:

  • PCM: 8kHz ~ 768kHz (8/16/24/32bits per Sample)
  • DSD Native: DSD64(1bit 2.8MHz), Stereo / DSD128(1bit 5.6MHz), Stereo
  • DSD256(1bit 11.2MHz), Stereo / DSD512(1bit 22.4MHz), Stereo

Outputs: Unbalanced Out (3.5mm), Balanced Out (2.5mm, only 4-pole supported / 4.4m, only 5-pole supported)

Output Level:

  • [Normal Gain] Unbalanced 2Vrms / Balanced 4Vrms (Condition No Load)
  • [High Gain] Unbalanced 3Vrms / Balanced 6Vrms (Condition No Load)

DAC: AKM AK4493SEQ x 2 (Dual DAC)

Decoding: Support up to 32bit / 768kHz Bit-to-Bit playback

Dimensions: 3.03″(77mm)[W] x 2.99″(76mm)[H] x 0.78″(19.9mm)[D]

Weight: 90g (3.17oz)

Playback Time: about 14hours (Standard: FLAC, 16bit, 44.1kHz, Unbalanced, Vol.50, LCD Off)

Audio Specifications

Frequency Response:

  • ±0.09dB (Condition: 20Hz~20kHz) Unbalanced / ±0.04dB (Condition: 20Hz~20kHz) Balanced
  • ±0.65dB (Condition: 20Hz~70kHz) Unbalanced / ±0.65dB (Condition: 20Hz~70kHz) Balanced


  • [Normal Gain] 121dB @ 1kHz, Unbalanced / 121dB @ 1kHz, Balanced
  • [High Gain] 125dB @ 1kHz, Unbalanced / 125dB @ 1kHz, Balanced


  • [Normal Gain] -134dB @ 1kHz, Unbalanced / -138dB @ 1kHz, Balanced
  • [High Gain] -135dB @ 1kHz, Unbalanced / -143dB @ 1kHz, Balanced


  • [Normal Gain] 0.0003% @ 1kHz, Unbalanced / 0.0004% @ 1kHz, Balanced
  • [High Gain] 0.0005% @ 1kHz, Unbalanced / 0.0006% @ 1kHz, Balanced

IMD SMPTE: 0.0003%, 800Hz 10kHz (4:1), Unbalanced / 0.0003%, 800Hz 10kHz (4:1), Balanced

Output Impedance: 3.5mm (1ohm) / 2.5mm (1.5ohm) / 4.4mm (1.5ohm)