SMSL DO400 Review

Specifications

Dual Sabre ES9039MSPRO + XMOS XU-316

Once again, SMSL laid out a balanced design, giving the DO400 a top-of-the-line ESS ES9039MSPRO DAC, embedding MQA hardware decoding, up to 8 channels active at the same time and super high dynamic range. 

Advertised as a “fully redesigned flagship 32bit 8 channel Digital-to-analog converters that target high end consumer devices and professional audio applications”, this new chip embeds ESS patented Hyperstream IV and a QUAD modulator architecture that allows +132dB DNR, per channel, or +140dB DNR in mono mode.

Upstream, to feed those chips, the brand gifted the DO400 an ARM CPU and the latest generation of XMOS chips, the XU-316, now paired with no less than 11 TI OPA1312A OP-AMP,  that makes the DAC “noiseless, or almost”. Dedicated to the USB and I2S (HDMI) port, this chip offers full support for 32-bit PCM stream, up to 768kHz, and DSD512/DoP256 files for utmost precision.

As for the headphone output itself, SMSL designed a set of 4-way PLFC headphones amplifier circuit, capable of delivering up to 2000mW output power, and less than 0.0001% distortion under a 16 ohm load.

Yet, the “piece of resistance” remains the fully-balanced circuitry.  haven’t opened this device, but from the official pictures, the cleanliness of the build is evident: a blackboard with symmetrical supply lines, all topped off with perfectly aligned capacitors, ready to perform. Numbers? With a 32 ohm Load, the SMSL DO400 harmonic distortion reaches an abysmal level (0.00005%) while maintaining a spectacular signal-to-noise ratio (133dB). A figure not easily surpassed by many DACs, even those in a higher price range.

Last but not least, SMSL gave us some measurements and if I couldn’t do the same, RMS Level and scope are always interesting to look at, from an objective point of view. Line level, the DO400 reaches 123dB/125 per channel, with a 0.000054% THD+N ratio.

Bundle

Inside the box

As usual with SMSL, the DO400 bundle is good but only comes with the strict minimum. 

Inside, you’ll find:

• the SMSL DO400
• a power plug
• one Bluetooth antenna
• a type-A to type-A USB cable
• an IR remote (without batteries)
• some documentation

Again, no RCA cable, nor XLR cable to plug your amplifier or speakers, which appears to be the norm in this price range, the brands usually leaving you the choice. And so, all you’re going to need after that is a good source like a computer, a digital transport, or even a DAP with a digital output – it’s up to you.

For the nerdiest one, here is the full technical data, for the rest, you can go to the next page already.

Technical Data

• Model: SMSL DO400
• Type: Digital Audio Converter + Desktop amplifier
• DAC: ESS Sabre ES9039MSPRO
• Digital controller: XMOS XU-316

• Outputs : RCA, XLR, 4.4mm Pentaconn, 6.35mm Jack, XLR 4-Pins
• Input: USB, Optical, Coaxial, Bluetooth, HDMI, AES/EBU
• THD: 0.000005% (XLR), 0.00007% (RCA), 0.00009% (Headphone)
• SNR: > 133dB (XLR), 128dB (RCA), 126dB (Headphone)
• Output power: 6000 mW @ 16 ohms / 3000 mW @ 32 ohms, 700 mW @ 300 ohms / 350 mW @ 600 ohms
• Line out level: 5.2Vrms (XLR), 2.5Vrms (RCA)
• Output impedance: 100 ohms (line out) / <0.1 ohm (headphone out)
• Sampling rate: USB/I2S – PCM up to 32bit/768kHz / DSD512,( Optical/Coaxial/AES – PCM up to 24bit/192kHz / DSD64(DoP)
• MQA compatibility: full decoder (USB, Opt, Coax, AES) 
• MQA-CD compatibility: full decoder (Opt, Coax, AES)
• Bluetooth: SBC / AAC / aptX / aptX HD / LDAC
• Size : 245mm x 186mm x 42mm
• Weight: 1450g
• Power consumption: <40W (in use), < 0.5W (idle)
• Price: $499

The review continues on Page four, after the click HERE or by using the jump below.

Page 1: About the brand

Page 2: Design & Build Quality, UI & Usage 

Page 3:UI & Usage 

Page 4: Specifications, Bundle

Page 5: Sound performances