SMSL D400 Mk2 High Resolution USB Desktop DAC

Flagship DAC with 5 Dual Op-Amps The D400 MK2 is a high-performance desktop DAC built around AKM’s flagship AK4191 and AK4499EX conversion architecture, third-generation XMOS XU-316 processing, a precision 10 MHz OCXO clock, and five dual op-amps. It supports PCM up to 32-bit/768 kHz, native DSD512, MQA and MQA-CD decoding, plus LDAC Bluetooth playback up to 24-bit/96 kHz. RCA and XLR analog outputs provide flexible integration with headphone amplifiers, preamplifiers, and other audio components. Flagship AKM conversion The D400 MK2 combines the AK4191 digital processing stage with the AK4499EX DAC for low-noise, low-distortion conversion. Measured XLR performance reaches 132 dB dynamic range and 132 dB SNR, with THD+N rated at 0.00006% (-124 dB, unweighted). The architecture is designed to preserve low-level detail while maintaining accurate channel performance across demanding digital sources. Third-generation XMOS processing An XMOS XU-316 digital processing platform handles high-resolution USB and I²S signals. USB and I²S PCM playback is supported from 44.1 kHz through 768 kHz, while DSD support extends from 2.8224 MHz through 22.5792 MHz, including native DSD512. USB and I²S support 1-bit and 16- to 32-bit data. MQA and MQA-CD decoding Hardware support includes MQA decoding through USB, optical, and coaxial inputs, along with MQA-CD playback. This allows compatible encoded material to be decoded directly by the D400 MK2 rather than relying entirely on upstream software processing. Precision OCXO clocking A built-in ±5 ppb, 10 MHz oven-controlled crystal oscillator provides a stable timing reference for digital conversion. SMSL’s CK-04 clock processing circuit further addresses timing jitter before conversion, helping maintain consistent signal timing and stereo imaging. Comprehensive digital inputs Digital connectivity includes USB, optical, coaxial, AES/EBU, I²S, and Bluetooth. I²S supports native DSD transmission, while coaxial and optical connections support DoP64. A dedicated DoP indicator provides a clear visual reference when compatible DSD-over-PCM signals are being received. High-resolution Bluetooth A Qualcomm Bluetooth platform supports LDAC, aptX HD, aptX, SBC, and AAC codecs. LDAC playback reaches 24-bit/96 kHz at up to 990 kbps, giving the D400 MK2 a wireless input option for compatible phones, tablets, computers, and streamers without replacing its higher-bandwidth wired connections. Independent low-noise power regulation Separate low-noise voltage regulation supplies the DAC, op-amp, digital, and analog sections independently. This power architecture is intended to reduce interaction between critical circuit stages while maintaining stable operating conditions throughout the signal path. Five dual op-amps Five high-grade dual op-amps form part of the D400 MK2 analog stage. Combined with dedicated power regulation and the AKM conversion platform, the output circuitry is designed for low residual noise and distortion across both RCA and XLR connections. CNC-machined aluminum chassis The enclosure is machined from a single block of aerospace-grade aluminum alloy. Its rigid all-metal construction provides electromagnetic shielding for the internal circuitry while creating a clean, durable exterior suited to a desktop audio system. Fully laminated color display A tempered-glass, fully laminated IPS color display presents input, decoding, and operating information with wide viewing angles and clear visibility. The front panel also includes a multifunction control knob, indicator light, and infrared remote receiver. Gold-plated connections Gold-plated input and output terminals provide strong oxidation resistance and reliable electrical contact over repeated use. The rear panel includes balanced XLR outputs, RCA outputs, AES/EBU, coaxial, optical, USB, and I²S digital inputs, along with the Bluetooth antenna and AC power inlet. Remote operation The supplied remote provides power control, directional navigation, menu and confirmation functions, input selection, mute, programmable FN control, and volume adjustment. Core functions can be accessed without reaching for the front-panel control. Product highlights AK4191 plus AK4499EX flagship AKM DAC architecture Third-generation XMOS XU-316 digital processing PCM decoding up to 32-bit/768 kHz Native DSD playback up to DSD512 MQA decoding and MQA-CD support Built-in ±5 ppb, 10 MHz OCXO CK-04 clock processing circuit Five high-grade dual op-amps LDAC Bluetooth playback up to 24-bit/96 kHz USB, optical, coaxial, AES/EBU, I²S, and Bluetooth inputs Balanced XLR and RCA analog outputs Fully laminated IPS color display CNC-machined aluminum chassis Gold-plated input and output terminals Hi-Res Audio certified Remote control included Specs DAC chipset: AK4191 plus AK4499EX USB processor: Third-generation XMOS XU-316 Inputs: USB, optical, coaxial, I²S, Bluetooth, AES/EBU Outputs: RCA, XLR XLR output level: 5 Vrms RCA output level: 2.5 Vrms XLR output impedance: 200 Ω RCA output impedance: 100 Ω XLR THD+N: 0.00006% (-124 dB), unweighted RCA THD+N: 0.00008% (-121 dB), unweighted XLR dynamic range: 132 dB RCA dynamic range: 126 dB XLR SNR: 132 dB RCA SNR: 126 dB USB transmission: Asynchronous Windows compatibility: Windows 7, 8, 8.1, 10, and 11, driver required Mac compatibility: macOS 10.6 or later Linux compatibility: Driverless operation supported MQA decoding inputs: USB, optical, coaxial USB and I²S bit depth: 1-bit, 16- to 32-bit Optical and coaxial bit depth: 1-bit, 16- to 24-bit USB and I²S PCM sampling rate: 44.1 to 768 kHz USB and I²S DSD sampling rate: 2.8224 to 22.5792 MHz Optical and coaxial PCM sampling rate: 44.1 to 192 kHz LDAC: 24-bit/96 kHz, 990 kbps, 660 kbps, or 330 kbps aptX HD: 24-bit/48 kHz, 576 kbps aptX: 16-bit/44.1 kHz, 352 kbps SBC: 16-bit/44.1 kHz, 328 kbps AAC: 16-bit/44.1 kHz, 320 kbps OCXO: ±5 ppb, 10 MHz Power consumption: Less than 10 W Standby power: Less than 0.5 W Dimensions: 10 × 7.44 × 1.81 in (254 × 189 × 46 mm) Weight: 4.18 lb (1.9 kg) What’s included D400 MK2 DAC Remote control