SMSL D400 EX User Manual

Safety Notes

• Install the unit in a well-ventilated, cool, dry, and clean location, away from direct sunlight, heat sources, vibration, dust, moisture, or cold.
• Use only the specified voltage. Using a higher voltage is dangerous and may cause fire, damage, or personal injury. The company is not liable for damage caused by using incorrect voltage.
• Do not attempt to modify or repair the unit yourself. Contact a salesperson or customer service for any service needs. The cabinet should never be opened.
• When not using the unit for extended periods (e.g., vacation), disconnect the power cable from the AC wall outlet.

Important Note: Product specifications and information are for reference only and subject to change without notice.

Warranty Terms

Foshan Shuangmusanlin Technology Co., Ltd. promises good-quality products. If the product fails within 7 days of purchase under normal use, customers may choose return, replacement, or repair (return is only possible if the product does not affect second sales). Free repair is provided for one year under normal use.

The date of purchase is based on the invoice or receipt from the seller. Online purchases can use a screenshot of the transaction.

The warranty will be void if the unit is damaged due to inappropriate usage, including:

• Use in non-normal working environments or failure to follow instructions.
• Private dismantling, refitting, or repairing.
• Damage caused by using non-specified or unaccredited accessories.
• Inability to provide credible proof of purchase.

Repairs typically require sending the unit back to the company or contacting your local SMSL Audio reseller.

Features

• Supports MQA decoding and MQA-CD.
• Features the 3rd generation XMOS XU-316 for PCM up to 32bit/768kHz and DSD up to DSD512.
• Equipped with flagship DAC chips: 1x AK4191 and 2x AK4499EX for maximum performance.
• Dual mono design with one AK4499EX per channel, achieving distortion as low as 0.00006% (-124dB).
• Utilizes 9 high-end dual op amps and numerous audiophile-grade components.
• Incorporates a 2nd PLL to eliminate JITTER during SPDIF transmission.
• Features a self-developed CK-03 clock processing circuit to significantly reduce clock jitter.
• Supports DOP independent display for accurate decoding format identification.
• USB, Optical, Coaxial, AES, and I2S inputs support DSD transmission; Coaxial and Optical also support DOP64.
• Features a tempered glass, full-fit color IPS display.
• Built-in low-noise power processing enhances power efficiency and reduces consumption.
• A system of multiple low-noise regulated power supplies ensures stable, reliable, and efficient operation.
• Includes a Qualcomm high-end Bluetooth chip supporting LDAC (24bit/96kHz), APTX/HD, SBC, and AAC.
• Housed in a high-quality all-aluminum alloy shell with gold-plated input and output terminals.
• Certified by the Japan Audio Association (JAS) for Hi-Res audio.
• Comes with a remote control for convenient operation.

Specifications

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

Remote Control

Operation Notes:

• If the remote control is ineffective when close to the unit, replace the battery.
• If the remote control will not be used for a long time, remove the batteries.
• Dispose of used batteries according to local regulations.

Operating the Remote Control:

The remote control features the following buttons:

• Power ON/OFF: Turns the unit on or off.
• Up: Navigates menus upwards.
• MENU/OK: Enters menus or confirms selections.
• Next level menu: Navigates to sub-menus.
• Return: Exits the current menu.
• Down: Navigates menus downwards.
• Input select: Cycles through input sources.
• Mute: Mutes or unmutes the audio output.
• FN (Define in the menu): Assignable function key.
• Volume +/-: Adjusts the audio volume.

Note: This remote controller requires 2 x R03/AAA batteries.

Display Interface and Instructions

The front panel of the SMSL D400 EX includes:

• Display: Shows audio information, settings, and status.
• Knob: Used for volume adjustment, menu navigation, and function selection. A short press enters the menu or confirms, while a long press exits menus or powers the unit on/off.
• Buttons: Power ON/OFF, Menu, and FN buttons provide direct control.

Front Panel Components (Numbered):

• 1: Turn on/off button
• 2: Menu button
• 3: FN button
• 4: Knob
• 5: Display
• 6: Remote window (Infrared receiver)
• 7: AC IN (Power input)
• 8: I2S input
• 9: USB input
• 10: Optical input
• 11: Coaxial input
• 12: AES/EBU input
• 13: XLR output
• 14: Bluetooth antenna
• 15: RCA output

Bluetooth Operating Instructions:

• Connection: Switch input to Bluetooth, enable phone's Bluetooth, search for "SMSL D400 EX", pair, and confirm connection.
• Re-connection: If Bluetooth connection is lost, a short press of the Bluetooth button on the remote can re-establish the connection.
• Clear Pairing: Press and hold the Bluetooth Control button on the remote. If phones can no longer find the device, delete the saved "SMSL D400 EX" from the phone's Bluetooth settings and search again.

Instructions

Inputs

• USB
• BLUETOOTH
• OPTICAL
• COAXIAL
• AES/EBU
• I2S(HDMI)

Outputs

• ALL LINE OUT (All outputs)
• BALANCED (Balanced output)
• UNBALANCED (Unbalanced output)

PCM Filter

• SHARP ROLL-OFF
• SLOW ROLL-OFF
• SHORT SHARP
• SHORT SLOW
• SUPER SLOW
• LOW DISPERSION

DSD Filter

• WIDE (Wide mode)
• NARROW (Narrow mode)

Sound Color

• SOUND 1 (5.6M)
• SOUND 2 (5.6M)
• SOUND 3 (11M)
• SOUND 4 (11M)

The AK4499EX operates at sampling rates of 5.6448MHz and 11.2896MHz.

PRE MODE

PRE MODE controls the volume adjustment function for the output:

• VARIABLE: The output volume is controlled.
• FIXED: Disables volume adjustment, keeping the volume at its current value.
• FIXED DSD BYPASS: Enables direct DSD output. Volume for PCM or DSD is not adjusted; output amplitude is fixed around 3.7VRMS. DSD is output directly without processing.

FN KEY FOR

• OUTPUTS (Select output)
• BLUETOOTH (Switch to Bluetooth input)
• PHASE (Switch output phase)

I2S MODE

Selects the I2S interface mode:

• NORMAL: PS AUDIO format.
• REVERSED: DATA and LRCLK are reversed.

Note: This option matches different I2S interface standards. Check the signal source's interface definition before use.

Diagrams illustrate the pin configurations for I2S connections (NORMAL and REVERSED), detailing pins like DATA, BCK, MCLK, LRCLK, GND, DSD FLAG, and MUTE.

AUDIO PHASE

Adjusts the audio phase:

• NORMAL (2+,3-): Standard phase connection.
• INVERTED (2-,3+): Inverted phase connection.

Diagrams show the pin assignments for NORMAL and INVERTED audio phase connections.

DIMMER

Sets the display's automatic dimming time (5 seconds to 60 seconds). The screen turns off after the set time and reactivates with any remote or knob operation, reducing light pollution.

BRIGHTNESS

Adjusts the display brightness from LEVEL 1 to LEVEL 6.

RESET

• When on Bluetooth input, long-pressing the knob's middle button resets only the Bluetooth pairing status.
• When on other inputs, long-pressing the knob's middle button clears all system settings, including Bluetooth.