S.M.S.L AL400 Integrated Amplifier
The S.M.S.L AL400 is a compact all-in-one integrated amplifier that combines high-power Class D amplification, a high-resolution DAC, MM/MC phono stage, HDMI eARC, and Bluetooth streaming in a single chassis. Designed for versatile home audio systems, it delivers clean power, flexible connectivity, and practical features for both stereo and 2.1 setups.
TPA3255 Class D Amplification
At the core of the AL400 is the Texas Instruments TPA3255 Class D amplifier chip, delivering 165 W per channel into 4 Ω and 85 W per channel into 8 Ω with a THD+N of 0.003%. This efficient design provides strong drive capability for a wide range of speakers while maintaining low distortion and high efficiency.
Cirrus Logic CS43131 DAC and XMOS Interface
Digital conversion is handled by the Cirrus Logic CS43131 DAC paired with a third-generation XMOS XU-316 USB processor. The AL400 supports PCM up to 32-bit/768 kHz and native DSD up to DSD256 via USB, along with full MQA and MQA-CD decoding on USB, optical, and coaxial inputs.
HDMI eARC Connectivity
Built-in HDMI eARC allows direct connection to televisions for high-quality audio return with automatic volume synchronization. This makes the AL400 an effective central hub for both music and TV sound without the need for additional converters.
MM/MC Phono Stage
A low-noise built-in phono preamplifier supports both Moving Magnet (MM) and Moving Coil (MC) cartridges. Users can connect a turntable directly, eliminating the need for an external phono stage.
High-Resolution Bluetooth Streaming
Equipped with a Qualcomm Bluetooth chipset, the AL400 supports LDAC, aptX HD, aptX Adaptive, AAC, and SBC. This enables convenient high-resolution wireless playback from smartphones, tablets, and computers.
Parametric EQ and Subwoofer Control
A three-band parametric equalizer allows independent adjustment of frequency, gain, and Q-factor for precise sound tailoring. The dedicated subwoofer output includes adjustable volume, four selectable low-pass crossover points, and 0°/180° phase selection for seamless 2.1 system integration.
ROHM Volume Control and Premium Construction
Volume control is managed by the ROHM BD37524FS-E electronic volume chip for accurate adjustment and low distortion. The chassis features a CNC-machined aluminum panel with anodized finish, offering solid build quality and a clean modern appearance.
Comprehensive Connectivity
The AL400 provides a versatile set of inputs and outputs:
- Digital: USB-C, Optical, Coaxial, HDMI eARC, Bluetooth
- Analog: Stereo RCA line input, MM/MC Phono input with ground terminal
- Outputs: Speaker terminals, Subwoofer RCA output
About SMSL
Foshan ShuangMuSanLin Electronics Co., Ltd. (SMSL) is an established manufacturer specializing in high-fidelity desktop audio products. Focusing on digital-to-analog converters, amplifiers, and related components, SMSL has built a global reputation for combining strong measured performance, practical features, and clean industrial design across accessible price points.
Technical Specifications
Amplifier Chip: Texas Instruments TPA3255
DAC Chip: Cirrus Logic CS43131
USB Interface: XMOS XU-316
Output Power: 165 W × 2 (4 Ω), 85 W × 2 (8 Ω)
THD+N: 0.003%
SNR: 101 dB
Channel Separation: 100 dB
Inputs: RCA / USB / Optical / Coaxial / Phono (MM/MC) / HDMI eARC / Bluetooth
Outputs: Speaker terminals / Subwoofer RCA
USB PCM: 44.1–768 kHz (16–32 bit)
USB DSD: DSD64–DSD256
Optical/Coaxial PCM: 44.1–192 kHz (16–24 bit)
Optical/Coaxial DSD: DSD64 (DoP)
MQA Decoding: USB / Optical / Coaxial
Bluetooth: LDAC, aptX HD, aptX Adaptive, AAC, SBC
Power Consumption: 40 W
Dimensions: 254 × 45 × 210 mm
Weight: 1.7 kg
Q&A
What amplifier chip does the SMSL AL400 use?
It uses the Texas Instruments TPA3255 Class D amplifier chip.
What DAC chip is inside the AL400?
It features the Cirrus Logic CS43131 DAC paired with an XMOS XU-316 USB interface.
Does the AL400 support HDMI eARC?
Yes. It includes a built-in HDMI eARC input for direct connection to televisions.
Can I connect a turntable directly?
Yes. The AL400 has a built-in low-noise phono stage that supports both MM and MC cartridges.
What is the maximum sampling rate supported via USB?
PCM up to 32-bit/768 kHz and native DSD up to DSD256.
Does it support full MQA decoding?
Yes. Full MQA and MQA-CD decoding is available via USB, optical, and coaxial inputs.
