DL400 - Uncategorized S.M.S.L - Free user manual and instructions

Product Type	DAC and Headphone Amplifier
Brand	S.M.S.L
Model	DL400
Dimensions (W x H x D)	250 x 240 x 47 mm
Weight	1.74 kg / 3.84 lbs
Power Consumption	<40W (Operating), <0.5W (Standby)
Input Voltage	AC 100-240V, 50/60Hz
DAC Chip	ESS ES9039MSPRO
USB Controller	XMOS XU-316 (3rd generation)
Bluetooth Version	5.1 with Qualcomm chip, supports LDAC, aptX/HD, SBC, AAC
MQA Support	Full MQA decoder, MQA-CD support via USB, Optical, Coaxial
Maximum Sampling Rates	PCM: 768kHz/32bit, DSD: DSD512 (22.5792MHz)
Headphone Output Power	6000mW x 2 @16Ω, 3000mW x 2 @32Ω, 700mW x 2 @300Ω
THD+N	XLR: 0.00005%, RCA: 0.00007%, HPA: 0.00009%
Dynamic Range / SNR	XLR: 133dB, RCA: 127dB, HPA: 125dB
Output Impedance	LINE OUT: 100Ω, HPA: near 0Ω
Inputs	USB-C, Optical, Coaxial, Bluetooth, AES/EBU, I2S (HDMI)
Outputs	XLR Balanced, RCA Unbalanced, 4.4mm Headphone, 6.35mm Headphone
Remote Control	Included, uses 2 x AAA batteries
Warranty	1 year free repair, 7-day return for defects (conditions apply)
Safety Precautions	Use specified voltage; avoid water, heat, dust; do not open; disconnect when not in use
Maintenance	Clean with dry cloth; avoid solvents

Frequently Asked Questions - DL400 S.M.S.L

How do I set up the DL400 for the first time?

Connect the power cable, select the appropriate input (USB, Optical, etc.), and adjust the volume. For USB input, install the driver on Windows if needed. Mac/Linux are driverless.

How to play MQA audio on the DL400?

Use USB, Optical, or Coaxial input with any player that supports ASIO or WASAPI (e.g., foobar2000). Set computer volume to maximum for best signal. The display shows native MQA sample rate when playing.

Can I use Bluetooth with the DL400?

Yes, the DL400 has Qualcomm Bluetooth 5.1 supporting LDAC, aptX HD, SBC, and AAC. Pair via the device's Bluetooth menu or the remote.

What is the DPLL setting and when should I adjust it?

DPLL adjusts the internal phase-locked loop bandwidth. Use a lower value for better jitter performance with stable sources. Increase if you experience sound interruptions (e.g., with a TV source). Default is 7 of 15.

How do I reset the DL400?

From the main menu, select 'RESET'. For Bluetooth input, this resets pairing only. For other inputs, it clears all settings including Bluetooth.

What does the PRE MODE setting do?

PRE MODE controls whether the output volume is variable (adjustable via knob/remote) or fixed (for use with an external preamp). Set to VARIABLE for normal headphone/line operation.

How do I change the I2S mode?

Go to the menu and select I2S MODE. Set to NORMAL or REVERSED to match your source's I2S pinout. Check the source's interface definition before use.

What are the Sound Color options?

Nine tone modes (Rich1-3, Tube1-3, Crystal1-3) processed via DSP. They alter sound character without changing frequency response. Set to Standard to bypass.

How do I adjust the display brightness and auto-off?

Use the DIMMER setting to set auto-off time (5 to 60 seconds). Use BRIGHTNESS to adjust screen brightness. Screen re-lights on operation.

What is the warranty and how do I claim it?

One year free repair for normal use. 7-day return if defective. Contact S.M.S.L or your reseller. Warranty void if damaged by misuse, unauthorized repair, or missing proof of purchase.

USER MANUAL DL400 S.M.S.L

The contents of this manual may be changed with the edition, and are subject to change without notice.

Ver 1.1

S.M.S.L

安全注意事项

• English (英语)
• Chinese (中文)
• Janpanese (日语)
• Russian (俄语)

DIMMER (自动熄屏)

5秒\~60秒

• Install this unit in a well ventilated, cool, dry, clean place-away from direct sunlight, heat sources, vibration, dust, moisture, or cold..
Use the voltage specified on this unit Only. Using this unit with a higher voltage than specified is dangerous and may cause fire, damage to this unit, or personal injury. Our company will not be held responsible for any damage resulting from the use of this unit with a voltage other than that specified.
Do not attempt to modify or fix this unit by yourself. Contact alesperson 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 of time (i.e. when going 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. The Term of Service

Foshan Shuangmusanlin Technology Co., Ltd promises to offer good-quality products. If the product is broken in 7 days after purchasing when you use it normally, you can choose to send it back for return, replacement or repairing (only the product does not affect the second sales can be returned). Repairing for free in one year if you use it normally.

1. Date of purchase is in accordance with the date on invoice or receipt uesd by seller, and if you buy it on line, you can show the screenshot of trade.

2. If an inappropriate usage causes the unit damaged, the warranty will be void. As below.

• All damages by inappropriate use, including using it under non-normal working environment or without following the instructions.
• Dismantling, refitting, repairing by user in private.
- Causing damage by using some fittings instead of the designative or accredited ones.
- Cannot provide credible proof of purchase.

1. Sending it back to our company for repairing.

2. Contact your S.M.S.L Audio reseller for a return or replacement.

Features

• Support MQA decoding and MQA-CD;
- New 3rd generation XMOS XU-316, PCM support up to 32bit/768kHz, DSD support to DSD512;
- The new generation flagship DAC chip ES9039MSPRO of American ESS, built-in MQA hard decoding;
• Uses ultra-low phase noise and optimized clock processing circuitry processing for ultra-low clock jitter;
- Fully balanced design earphone amplifier circuit with 4 ultra-low distortion Precision Linear Feedback Circuit (PLFC), output power up to 6W×2 at 16 ohms, output power up to 3W×2 at 32 ohms;
• Two headphone output jacks, 4.4mm and 6.35mm, are available for different uses;
• All inputs except Bluetooth support DSD transmission, coaxial, optical, AES/EBU support DoP64;
- Firmware upgrade function, users can upgrade the system and USB firmware by themselves;
• Built-in low-noise power supply processing, while improving power efficiency and lowering power consumption;
• Specially designed power supply system matching and multiple low-noise regulated power supplies to provide low noise power supply for analog circuits;
• Qualcomm Bluetooth 5.1 chip supports LDAC 24bit/96kHz, APTX/HD, SBC, AAC, support for lyrics display function;
• High-quality gold-plated input and output connection terminals;
• Japan Audio Society (JAS) Hi-Res certification;
• Equipped with full-function remote control.

Specifications

Input		USB / Optical / Coaxial / Bluetooth /$ / AES/EBU
Output	LINE	RCA / XLR
	HPA	4.4mm Headphone Jack6.35mm Headphone Jack
Line Output Amplitude	XLR	5.2Vrms
	RCA	2.5Vrms
Headphone output power	16Ω	6000mW x 2
	32Ω	3000mW x 2
	300Ω	700mW x 2
THD+N	XLR	0.00005%(-125dB)(UN-WTD)
	RCA 0.00007%(-122dB)(UN-WTD)
	HPA	0.00009%(-120dB)(UN-WTD)
Dynamic range	XLR	133dB
	RCA 127dB
	HPA	125dB
	XLR	133dBSNR
	RCA	127dB
	HPA	125dB

Specifications

Output Impedance	LINE OUT	100Ω
	HPA	near 0Ω
	Balanced	+15.5dBHPA high gain
	Unbalanced	+9.5dB
USB transmission		USB2.0(Asynchronization)
USB compatibility		Windows 7 / 8 / 8.1 / 10 / 11(Needs Driver)Mac OSX 10.6 above, Android system, iOS, Linux(Driveless)
		USB / Optical / Coaxial / AES/EBUMQA decoder
MQA-CD decoder		Optical / Coaxial / AES/EBU
Sampling rate & Bit Width: USB/I2S		PCM 44.1~768kHz(32bit)
		DSD 2.8224~22.5792MHz (1bit)
		Optical/Coaxial/AES/EBU 44.1~192kHz(24bit)
		DoP DoP256(USB),DoP64( Optical / Coaxial)
Bluetooth Specification		5.1(support SBC,AAC,aptX,aptX HD,LDAC)
Power Consumption		<40W
Standby power		<0.5W
Size		250X240X47mm(WxHxD)
Weight		1.74kg/3.84lbs

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

Remote control

• If the remote control is still ineffective when it is close to the machine, replace it with a new battery.
• If the user does not use the remote control for a long time, remove the battery of the remote control.
• Dispose of used batteries in accordance with local regulations on battery disposal.

Operating the remote control

• This remote controller use 2 x R03/AAA batteries.

*Some of the remote control functions are effective only in the Bluetooth input state.

Power ON / OFF

Up / Pause/Play*

Menu / OK button

Next level menu / Next Song*

Return / Previous Song*

Down

Input select

Mute

FN(Define in the menu)

Volume +

Volume -

Display Interface and Instructions

12 Function knob
4 Display screen
7 RCA output
10 AES/EBU input
13 I²S input

□
5
8 Bluetooth antenna
11 Coaxial input
14 USB input

Indicator lightRemote window
6 6.35mm headphone jack4.4mm headphone
9 XLR output
12 Optical input
1 AC IN

Instructions

INPUTS

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

OUTPUTS

• ALL LINE OUT
  • HEADPHONE OUT
  BALANCED
• UNBALANCED

HPA GAIN

• LOW
  • HIGH

PCM FILTER

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

DSD FILTER

There are 4 kinds of digital filtering in total. It's the way that the digital operation means the clutter outside the audioFilter out, respectively

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

Instructions

SOUND COLOR

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

• Rich1, Rich2, Rich3
• Tube1, Tube2, Tube3
  • Crystal1, Crystal2, Crystal3

This setting is using the DSP of DAC, to make some different sound color, all of these settings will not change the frequency response curve. When set to "Standard", this setting will be bypassed.

PRE 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.

DPLL

• MIN \~ MAX

(A total of 15 kinds, the default is 7 kinds. The larger the number is, the stronger the range to adapt to jitter, and the smaller the number, the better the performance against clock jitter.)

This DPLL setting is a special function of ESS series products. It can adjust the internal DPLL digital phase locked loop circuit Bandwidth, so that the chip achieves a balance between anti clock jitter and input tolerance.

Its function:

• When the clock stability of the input signal is good, this value can be reduced, so that the clock performance of the system is better;
• When the clock stability of the input signal is not good, the sound may be interrupted. Increase this value can avoid the sound interruption! Especially when using TV as signal source!
• When the clock stability of the input signal is good, this value can be reduced, so that the clock performance of the system is better;
• When the clock stability of the input signal is not good, the sound may be interrupted. Increase this value can avoid the sound interruption! Especially when using TV as signal source!

FN KEY FOR

• SWITCH LINE/HPA
  • OUTPUTS
• BLUETOOTH
  PHASE

Instructions

I²S MODE

NORMAL

- REVERSED

Note: This option is used to match different I²S interface standards, please check the interface definition of the signal source before use

AUDIO PHASE

• NORMAL (2+,3-)

• INVERTED (2-,3+)

NOTE: When inverting the XLR phase, the RCA phase will also be inverted.

Instructions

LANGUAGE

• English
• Chinese
• Janpanese
  • Russian

DIMMER

- 5 second \~ 60 second (The range is 5 seconds-60 seconds. After setting, the screen will automatically go off within this time, and the screen will re-light up if you operate the remote control or the knob at any time.)

BRIGHTNESS

• For Bluetooth input, select "RESET" in the main menu of the DL400 and confirm. The system will reset the Bluetooth pairing status only;
• For other inputs, please select "RESET" from the DL400's main menu and confirm, 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 DL400 includes MQA technology, which enables you to playback MQA audio files and streams, delivering the sound of the original master recording.

Visit How it works https://www.mqa.co.uk/how-it-works for more information.

How to play MQA

• DL400 supports MQA decoding with USB, optical fiber and coaxial!
• DL400's MQA playback does not require the use of special playback software, such as foobar2000, Audirvanaplus only needs to support ASIO or WASAPI audio output, and when playing MQA audio, it is best to adjust the volume of the computer to the maximum, so that the audio output of the computer is in the best condition.
• When playing an MQA file, the sampling rate of the original master recording is displayed.

MQA

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

Notes on playing MQA-CD

• Please make sure that what is being played is a genuine MQA-CD.
• Verify that the optical or coaxial signal output of the CD player is an unprocessed source code.