SMSL AS400 Power Amplifier User Manual

1. Introduction

This manual provides detailed instructions for the setup, operation, and maintenance of your SMSL AS400 Power Amplifier. Please read this manual thoroughly before using the product to ensure proper functionality and to maximize your audio experience.

Figure 1: SMSL AS400 Power Amplifier (Silver)

Figure 2: SMSL AS400 highlighting its functions as DAC, Power Amp, and Headphone Amp.

2. 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 this unit with a higher voltage than specified is dangerous and may cause fire, damage to this unit, or personal injury. The manufacturer is not responsible for any damage resulting from the use of this unit with a voltage other than that specified.
• Do not attempt to modify or repair this unit yourself. Contact a salesperson or customer service if 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., during vacation), disconnect the power cable from the AC wall outlet.
• The product specifications and information mentioned in this manual are for reference only. The content of this manual is subject to change without notice.

3. Features

• Features German Infineon's new digital high-power amplifier chip MA5332MS for high quality, efficiency, and low energy consumption.
• Incorporates Japan's JRC electronic volume control chip NJW1194A for accurate volume control and ultra-low distortion.
• Built-in HDMI (ARC) interface for seamless TV audio integration.
• Supports MQA decoding and MQA-CD playback.
• Equipped with the new third-generation XMOS XU-316, supporting PCM up to 32bit/768kHz and DSD up to DSD256.
• High-end DAC chip CS43131 from Cirrus Logic (USA) for superior sound conversion.
• Built-in low-noise MM vinyl phono amplifier.
• Latest Bluetooth support for LDAC, APTX/HD, SBC, AAC codecs.
• All-aluminum alloy CNC precision-processed shell with anodizing technology and chamfering for exquisite workmanship.
• User-friendly operating system with full-function remote control.
• High-quality gold-plated input and output terminals.
• Includes perfect overheating and overcurrent protection circuits.
• Built-in high-quality, high-power audio special switching power supply.

Figure 3: Key audio components including Infineon MA5332MS amplifier, Cirrus Logic CS43131 DAC, and XMOS XU-316 USB interface.

4. Display Interface and Controls

Figure 4: Front and Rear Panel Overview of the AS400.

Front Panel

1. Function Knob: Press to enter the menu; Hold to exit the menu; Rotate to change the value or volume.
2. 4.4mm Headphone Jack
3. 6.35mm Headphone Jack
4. Remote Window
5. Display Screen

Rear Panel

6. PHONO Input: For connecting turntables.
7. LINE Input: Standard analog audio input.
8. Coaxial Input: Digital audio input.
9. HDMI(ARC) Input: For TV audio return channel.
10. Bluetooth Antenna: For wireless audio reception.
11. AC Power Input (100-240V AC)
12. Grounding Terminal
13. SW Out (Preamp): Subwoofer pre-out.
14. USB Input (PRE): USB audio input.
15. Optical Input: Digital audio input.
16. Right Channel Output: Speaker terminal.
17. Left Channel Output: Speaker terminal.

5. Remote Control

The AS400 comes with a full-function remote control for convenient operation. Ensure batteries are installed correctly (2 x R03/AAA batteries).

Figure 5: Remote Control Layout and Functions.

Remote Control Functions:

• Power ON/OFF: Turns the unit on or off.
• Up/Down: Navigate menu options or adjust settings.
• MENU/OK: Enters menu or confirms selection.
• Return: Goes back to the previous menu.
• Input Select: Cycles through available inputs.
• Mute: Mutes or unmutes audio.
• Output Switching: Switches between speaker and headphone outputs.
• Volume +/-: Adjusts the volume level.

Battery Information:

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

6. Setup and Connections

6.1. HDMI ARC Connection

Connect your TV's HDMI ARC port to the AS400's HDMI(ARC) input using a compatible HDMI cable.

Figure 6: Diagram for connecting TV via HDMI ARC to the AS400.

• Connect to an HDMI IN port labeled "ARC" or "eARC/ARC" on your TV. If connected to a port that does not support ARC, the ARC input function of this product cannot be used.
• Use an HDMI cable (19 pin) with the HDMI logo indicating compatibility with ARC. You may need to adjust TV settings; refer to your TV's user manual.
• This product supports digital audio input via HDMI ARC, but it cannot output video.
• If your TV does not support ARC, connect the TV's audio output (OPTICAL, COAXIAL, or AUX) to the corresponding input on the AS400.

6.2. Phono Input

Connect your turntable to the dedicated PHONO input on the rear panel. Ensure proper grounding for optimal sound quality.

Figure 7: Connecting a turntable to the built-in low-noise MM phono preamplifier.

6.3. Bluetooth Input

Pair your Bluetooth-enabled device with the AS400 to stream audio wirelessly.

Figure 8: Bluetooth input setup, supporting LDAC, APTX/HD, SBC, AAC.

Bluetooth Pairing:

• Open Bluetooth pairing on your mobile phone, search for and select "SMSL AS400".
• If your phone displays "Connected", pairing is successful.
• If pairing fails, use the Bluetooth clear function on the AS400 to clear previously connected devices, then retry.

6.4. Speaker and Headphone Outputs

Connect passive speakers to the speaker terminals on the rear panel. Use the 4.4mm or 6.35mm jacks on the front for headphones.

Figure 9: Example of a 2.1 channel system setup with the AS400 and a subwoofer.

• Speaker Connection: Pay attention to polarity (+ and -) when connecting speakers to ensure correct sound quality.
• Headphone Connection: The AS400 features both 4.4mm (balanced) and 6.35mm (unbalanced) headphone outputs.

Figure 10: Dual headphone jack design for diverse headphone compatibility.

7. Operation

7.1. Menu Navigation

Use the function knob on the front panel or the remote control to navigate the menu:

• Press Knob: Enter menu.
• Hold Knob: Exit menu.
• Rotate Knob: Change values or volume.

7.2. Input and Output Settings

The AS400 supports various input and output options, selectable via the menu:

• Input Settings: USB audio, Optical, Coaxial, Bluetooth, ARC IN, AUX IN, PHONO.
• Output Settings: Speakers, Headphones.

7.3. EQ and Tone Controls

Customize your sound with various EQ presets and tone adjustments.

• EQ Modes: Direct, Tone, SDB, Bass, Super Bass, Rock, Soft, Clear.
• Bass Adjustment Range: -9dB to +9dB. (Changing Bass in Direct or other EQ modes will switch to Tone mode).
• Treble Adjustment Range: -9dB to +9dB. (Changing Treble in Direct or other EQ modes will switch to Tone mode).

7.4. Digital Filters

Select from various digital filters to fine-tune the audio characteristics:

• Fast and Low-latency filter
• Fast and Phase-compensated filter
• Slow and Low-latency filter
• Slow and Phase-compensated filter
• Nonoversampling filter

7.5. Display Color Settings

Personalize the display screen color:

• White, Red, Green, Blue, Yellow, Cyan, Orange, Purple.

7.6. MQA Playback

The AS400 supports MQA decoding via USB, optical, and coaxial inputs.

• No special playback software is required for MQA playback. For optimal quality, set your computer's audio output to ASIO or WASAPI and adjust the computer volume to maximum.
• When playing MQA files, the display will show the sampling rate of the original master recording.

7.7. MQA-CD Playback

• Ensure the MQA-CD is genuine.
• Verify that the optical or coaxial signal output of your CD player is an unprocessed source code.

7.8. Dimmer Settings

Adjust the display brightness behavior:

• Always on: Display remains on.
• Auto off: Display turns off automatically after 5 seconds of inactivity.

7.9. Restore Factory Settings

• For Bluetooth Input: Press and hold the middle button of the knob to reset only the Bluetooth pairing status.
• For Other Inputs: Press and hold the middle button of the knob to erase all settings, including Bluetooth.

8. Troubleshooting (HDMI ARC Function)

Here are some common questions and answers regarding HDMI ARC functionality:

• Q1: The ARC input is connected to the TV, but the TV does not recognize the device or produce sound?
  A1: The ARC input needs to be connected to the HDMI ARC interface of the TV, and the output mode of the TV should be set to "ARC/ARC+TV speakers".
• Q2: Can the TV remote control adjust the volume of this product?
  A2: Not supported.
• Q3: Will the product synchronize on/off after turning on/off the TV?
  A3: Not supported. When using HDMI ARC input, this product needs to be restarted when the TV is turned off and then turned on again.
• Q4: What should I do if there is no sound after connecting the TV to the product?
  A4: When using this product, please confirm that the audio output format of the TV is PCM.
• Q5: Does it support connecting to a TV set-top box?
  A5: Not supported.

9. Specifications

Figure 11: Detailed technical specifications and dimensions of the AS400.

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

10. Warranty and Support

10.1. Warranty Terms

• Foshan Shuangmusanlin Technology Co., Ltd. offers good-quality products. If the product breaks within 7 days of purchase under normal use, you may choose a return, replacement, or repair (provided the product does not affect resale). Free repair is provided for one year under normal use.
• The purchase date is determined by the invoice or receipt from the seller. For online purchases, a screenshot of the transaction can serve as proof.
• The warranty will be void if the unit is damaged due to inappropriate usage, including:
  • Damage from use in non-normal working environments or not following instructions.
  • Dismantling, refitting, or repairing by the user.
  • Damage caused by using non-designated or non-accredited fittings.
  • Inability to provide credible proof of purchase.
• For returns or replacements, please send the product back to your S.M.S.L audio reseller.

10.2. Customer Support

For any questions or support needs, please contact your S.M.S.L audio reseller. The manufacturer, LIN.LIN.LIN, is committed to providing reliable products and customer service.

Figure 12: Customer support details for LIN.LIN.LIN AUDIO, the brand behind SMSL.