audio-sound @ hatena

An audio review & news blog. The volume should not exceed 80 dB is recommended. I usually adhere to the safe-listening style by WHO. Please note that my aural impressions and interpretations of measurements are also made from a safe-listening style.

S.M.S.L D400EX: AK4191 & Dual AK4499EX DAC Chips DSD512 Bluetooth Audio Decoder




The SMSL D400EX high-end DAC is now available with dual AK4499EX, Asahi Kasei's latest flagship DAC chip.



  • Flagship AK4191 & Dual AK4499EX DAC Chips
  • Brand New 3rd-Generation XMOS USB Solution
  • High-End Bluetooth Connectivity
  • Multiple Input & Output Options
  • Built-In Digital Filters & Low-Noise Power Processing



  • Input: USB /Optical/ Coaxial / l2S /Bluetooth /AES
  • Output: RCA /XLR
  • THD+N:
    • 0.00006%(-124dB)
    • 0.000053%(-125.5dB) (A-WTD)
  • Dynamic range:
    • XLR: 133dB
    • RCA: 128dB
    • SNR: 133dB
  • USB transmission: Asynchronization
  • USB compatibility: Windows 7 / 8/ 8.1/ 10, Mac OSX、Linux
  • Bit depth:
  • USB / I2S: 1bit,16 ~ 32bit
  • Optical / Coaxial: 1bit, 16~32bit
  • Sampling rate:
    • USB / I2S-
    • PCM: 44.1 ~768kHz
    • DSD: 2.8224~22.5792MHz
    • Optical / Coaxial-PCM: 44.1 ~192kHz
  • Bluetooth specification:
    • LDAC: 24bit/96kHz (990kbps/660kbps/330kbps)
    • aptX-HD: 24bit/48 kHz_576kbps
    • AptX: 16bit/44.1 kHz_352kbps
    • SBC: 16bit/44.1kHz_328kbps
    • AAC: 16bit/44.1kHz_320kbps
  • Power Consumption: 6W
  • Standby power: <0.5W
  • Size: 40×188X46mm (WxHxD)
  • Weight: 1.85kg/4.08lb


Flagship AK4191 & Dual AK4499EX DAC Chips

To tap into the full potential of the chips, SMSL has equipped the D400EX with a flagship-grade Dual DAC chipset featuring two AK4499EX latest-generation DAC Chips from AKM Technologies. D400EX also houses one AK4191 Chip to complement the AK4499EX DACs. The AK4499EX is a 32-Bit flagship DAC chip from AKM that provides unmatched performance while decoding high-resolution audio signals.


Brand New 3rd-Generation XMOS USB Solution

To get the best out of the flagship DAC Chipset present on the D400EX, SMSL has featured an XU316 USB processor from XMOS Technologies. It enables the D400Ex to decode high-resolution 32-Bit/768kHz PCM signals and native DSD512 audio signals.


High-End Bluetooth Connectivity

Supporting high-resolution wireless Bluetooth connectivity for signal input, SMSL D400EX high-tech Desktop DAC adopts the latest QCC5125 Bluetooth processor from Qualcomm that supports high-res LDAC, AptX HD, AptX, SBC, and AAC transmission protocols. especially, LDAC allows the users to stream at 24-bit/96kHz bit rate.


Multiple Input & Output Options

D400EX features a wide range of input options, including IIS, USB, Coaxial, Optical, and Bluetooth. Users will be able to easily connect the D400 EX with different sources easily. Besides, SMSL D400EX utilizes High-quality gold-plated input and output connection terminals.


Built-In Digital Filters & Low-Noise Power Pro cessing

Adopting seven different digital filters for PCM signals built into the D400EX, the SMSL equipped with multiple low-noise regulated power supplies to provide a stable, reliable and funny low-noise power supply system. Users can use these to adjust the output more to their liking.


Price & Availability

SMSL D400EX is now available at Linsoul and others for $959.99.