S.M.S.L DO400 User Manual

Safety Notes

• Install this unit in a well-ventilated, cool, dry, clean place, away from direct sunlight, heat sources, vibration, dust, moisture, or cold.
• Use only the voltage specified for this unit. Using a higher voltage is dangerous and may cause fire, damage to the unit, or personal injury. S.M.S.L will not be held responsible for any damage resulting from the use of this unit with an unspecified voltage.
• Do not attempt to modify or fix this unit by yourself. Contact a salesperson or customer service when any service is needed. The cabinet should never be opened for any reason.
• When not planning to use this unit for long periods (e.g., when on vacation), disconnect the power cable from the AC wall outlet.

Important note:

The product specifications and information mentioned in this manual are for reference only. The content of this manual is subject to change without notice.

Warranty Terms

1. Term of Service

Foshan Shuangmusanlin Technology Co., Ltd promises to offer good-quality products. If the product breaks down under normal use within 7 days of purchase, customers can choose to return, replace, or repair it (only if the product does not affect secondary sales). Free repair is provided for one year if the product is used normally.

2. Date of Purchase

The purchase date is determined by the date on the invoice or receipt provided by the seller. For online purchases, a screenshot of the transaction can be used.

3. Warranty Void Conditions

The warranty will be void if inappropriate usage causes damage, including:

• All damages due to inappropriate use, including use under non-normal working environments or without following instructions.
• Dismantling, refitting, or repairing by the user privately.
• Damage caused by using fittings other than designated or accredited ones.
• Inability to provide credible proof of purchase.
• Product not belonging to Foshan Shuangmusanlin Technology Co., Ltd.

4. Repair Method

Sending the unit back to Foshan Shuangmusanlin Technology Co., Ltd for repair.

5. Contact Information

Customers should contact their S.M.S.L Audio reseller for returns or replacements.

Features

• Supports MQA decoding and MQA-CD.
• Features the new 3rd generation XMOS XU-316, supporting PCM up to 32bit/768kHz and DSD up to DSD512.
• Equipped with the new generation flagship ESS DAC chip ES9039MSPRO, with built-in MQA hard decoding.
• High output power: 6W at 16 ohm and 3W at 32 ohm.
• Fully balanced design with a 4-way ultra-low distortion precision linear feedback circuit (PLFC).
• Three types of headphone output connectors: 4-XLR, 4.4mm, and 6.35mm, to meet various purposes.
• Specially designed linear regulated power supplies for discrete components and multiple low-noise regulated power supplies provide analog circuits with low noise power.
• All input ports except Bluetooth support DSD transmission; coaxial, optical fiber, and AES/EBU support DoP64.
• Firmware upgrade function allows users to upgrade the system and USB firmware themselves.
• Built-in low-noise power processing improves power efficiency and reduces power consumption.
• Qualcomm's latest Bluetooth 5.1 chip supports LDAC 24bit/96kHz, APTX/HD, SBC, and AAC.
• High-quality gold-plated input and output connection terminals.
• Japan Audio Society (JAS) Hi-Res certification.
• Equipped with a remote control for full-featured remote operation.

Specifications

SMSL reserves the right to make improvements which may result in specification or feature changes without notice.

Remote Control

• If the remote control is ineffective when close to the machine, replace the battery with a new one.
• If the remote control will not be used for a long time, remove its battery.
• Dispose of used batteries in accordance with local regulations on battery disposal.

Operating the Remote Control

This remote controller uses 2 x R03/AAA batteries.

Display Interface and Instructions

Package List

• 1 x S.M.S.L DO400 Unit
• 1 x USB cable
• 1 x Warranty card
• 1 x Remote control
• 1 x AC power cable
• 1 x Bluetooth antenna
• 1 x User manual

Instructions

Inputs

• USB
• Bluetooth
• Optical
• Coaxial
• AES/EBU
• I²S (HDMI)

PCM Filter

• FILTER OFF
• MINIMUM PHASE
• APODIZING
• LINEAR FAST
• LINEAR SLOW
• MINIMUM FAST
• MINIMUM SLOW
• LOW DISPERSION

Outputs

• ALL LINE OUT
• HEADPHONE OUT
• BALANCED
• UNBALANCED

DSD Filter

There are 4 kinds of digital filtering. This digital operation filters out clutter outside the audio range.

• 47kHz Cutoff
• 50kHz Cutoff
• 60kHz Cutoff
• 70kHz Cutoff

PRE MODE (Preamplifier Mode)

PRE MODE is the volume adjustment function switch for the output interface:

• VARIABLE: The output interface volume is controlled.
• FIXED: The output interface volume is fixed.

HPA GAIN (Headphone Amplifier Gain)

• LOW
• HIGH

SOUND COLOR (Tone Menu)

This machine has a total of 9 tone modes, processed by DSP through the DAC:

• Rich1, Rich2, Rich3 (Harmonic rich)
• Tube1, Tube2, Tube3 (Tube sound)
• Crystal1, Crystal2, Crystal3 (High clarity)

These settings use the DAC's internal DSP to create different sound effects and do not change the frequency response curve. When set to "Standard", this function is bypassed.

DPLL (Digital Phase-Locked Loop Settings)

• MIN ~ MAX (15 kinds total, default is 7 kinds. A larger number means a stronger range to adapt to jitter, while a smaller number means better performance against clock jitter.)

This DPLL setting is a special function of ESS series products. It adjusts the internal DPLL digital phase-locked loop circuit bandwidth, balancing anti-clock jitter and input tolerance.

Its function:

• When the clock stability of the input signal is good, this value can be reduced for better system clock performance.
• When the clock stability of the input signal is not good, sound may be interrupted. Increasing this value can prevent sound interruption, especially when using a TV as a signal source.

FN KEY FOR (FN Button Function)

• SWITCH LINE/HPA (Switch between Line and Headphone Amp)
• OUTPUTS (Output selection)
• BLUETOOTH (Switch to Bluetooth input)
• PHASE (Output phase selection)

I²S MODE

This option is used to match different I²S interface standards. Please check the interface definition of the signal source before use.

GND 1  2 I²S DATA +I²S BCK +   I²S DATA -I²S BCK -   GNDGND     I²S LRCLK +I²S MCLK +   I²S LRCLK -I²S MCLK -   GNDNC       NC MUTE      DSD FLAGNC       NC18      19 GND

GND 1  2 I²S DATA -I²S BCK +   I²S DATA +I²S BCK -   GNDGND     I²S LRCLK -I²S MCLK +   I²S LRCLK +I²S MCLK -   GNDNC       NC MUTE      DSD FLAGNC       NC18      19 GND

AUDIO PHASE

DIMMER (Automatic Screen Off)

• 5 seconds ~ 60 seconds (After setting, the screen will automatically go off within this time. It will re-light up if the remote control or knob is operated. This reduces light pollution and improves listening comfort.)

BRIGHTNESS (Display Brightness Setting)

• LEVEL 1 ~ LEVEL 6

RESET (System Reset)

• During Bluetooth input, long press the middle button of the knob. The system will only reset the Bluetooth pairing status.
• During other inputs (non-Bluetooth), long press the middle button of the knob. The system will clear all settings, including Bluetooth.

About MQA

MQA (Master Quality Authenticated) is an award-winning British technology that delivers the sound of the original master recording. The master MQA file is fully authenticated and is small enough to stream or download. The DO400 includes MQA technology, enabling playback of MQA audio files and streams, delivering the sound of the original master recording.

For more information, visit https://www.mqa.co.uk/how-it-works.

Important note:

The product specifications and information mentioned in this manual are for reference only. The content of this manual is subject to change without notice.

How to Play MQA

• The DO400's USB, optical fiber, and coaxial inputs support MQA decoding.
• The DO400's MQA playback does not require special playback software like foobar2000 or Audirvanaplus; it only needs to support ASIO or WASAPI audio output. When playing MQA audio, it is best to adjust the computer's volume to maximum for optimal audio output.
• When playing an MQA file, the display shows the sampling rate of the original master recording.

MQA and the Sound Wave Device are registered trademarks of MQA Limited. © 2016

Notes on Playing MQA-CD

• Ensure that the disc being played is a genuine MQA-CD.
• Verify that the optical or coaxial signal output from the CD player is an unprocessed source code.