SMSL AL400 All-in-One Hi-Fi Decoder/Preamp/Phono Power Amp TPA3255 amp & CS43141 DAC chip Full MQA, MM & MC Cartridge HDMI(eARC), for TV Home theater Subwoofer Desktop Bookshelf passive speakers

 

Key Features:

• Power Output: Delivers robust, clean amplification rated at 2 × 85 W at 8Ω or 2 × 165 W at 4Ω, making it highly capable of driving both bookshelf and floor-standing speakers.
• High-Res Decoding: Handles PCM up to 32 bit/768 kHz, native DSD256, and full MQA/MQA-CD hardware decoding.
• Integrated Phono Preamp: Includes a built-in, low-noise phono stage supporting both Moving Magnet (MM) and Moving Coil (MC) turntable cartridges.
• Advanced Connectivity: Features HDMI (eARC) for TV syncing, USB, Optical, Coaxial, and RCA inputs, along with LDAC and aptX HD Bluetooth for wireless streaming.
• Subwoofer Support: Offers a dedicated sub-out with an adjustable low-pass filter (40Hz–250Hz) and 0°/180° phase adjustment for 2.1 channel setups.
• Parametric EQ: Features a 3-band customizable EQ (adjusting frequency, gain, and Q-value) so you can tailor the audio to your room or speakers.

 

Core Audio Components:

• DAC Chip: Features dual Cirrus Logic CS43131 chips alongside a third-generation XMOS XU-316 USB processor.
• Decoding: Supports native DSD256, PCM up to 32-bit/768kHz, and full MQA decoding.
• Volume Control: Employs the Japanese-made ROHM BD37524FS-E electronic volume control for ultra-low distortion across the dynamic range.

 

Connectivity:

• Inputs: HDMI eARC for TV integration (syncs audio and power), Bluetooth 5.1 (supporting LDAC and aptX HD), USB, Optical, and Coaxial.
• Turntable Ready: Built-in low-noise phono preamplifier compatible with both MM (Moving Magnet) and MC (Moving Coil) cartridges.
• Outputs: Professional subwoofer management with adjustable low-pass filters (four cutoffs), and 0°/180° phase control

 

EQ and Tuning:

The SMSL AL400 offers professional-grade sound customization. It features an adjustable 3-band EQ (high, medium, and low frequencies) where you can independently set the frequency points, gain, and Q values.

 

Reviews & Insights:

• EQ: On forums like Audio Science Review (ASR), users appreciate the detailed 3-band parametric EQ, though opinions are mixed regarding whether a 3-band system provides enough flexibility for rigorous room corrections.
• HDMI eARC: When using the HDMI ARC connection, reviewers note that there can be a slight lag in volume adjustments, but CEC integration conveniently allows you to power the amp on/off with your standard TV remote.

 

 

TPA3255 Amp chip:

• Tl digital high power amplifier chip TPA3255 has lower distortion, high efficiency and low energy consumption;
• The electronic volume control chip BD37524FS-E of Japan ROHM Company isused, which has accurate volume control and ultra-low distortion.
• Different frequency points can be set in the high, medium and low frequency bands, and with different gains and different Q values, the frequency response curve of the output of the power amplifier can be adjusted conveniently and accurately, so as to meet the needs of different speakers and different listening environments as much as possible.
• The output volume of the subwoofer is adjustable, four low-pass cutoff frequencies are selected, and the selection of phase 0 and 180 makes the main speaker in the2.1 speaker system better match with the active subwoofer.
• Built-in low noise vinyl head amplifier, which can adapt to the use of MM and MC heads;
• Built-in HDM(eARC) receiver;
• Support MQA decoding and MQA-CD decoding;
• The third generation XMOS XU-316, PCM supports to 32bit/768kHz, and DSD supports to DSD256;
• Cirrus Logic's new high-end DAC chip CS43131!
• The latest high-resolution Bluetooth supports LDAC，APTX/HD,SBC and AAC! Aluminum alloy CNC processing panel technology, using anodic oxidation technology, fine workmanship, first-class touch;
• The humanized operating system is easy to understand and equipped with full-function remote control function;
• Adopt audiophile-grade audio components to improve subjective hearing. High quality gold-plated input and output terminals;
• Perfect protection circuits such as overheating and overcurrent;
• Built-in high-quality high-power audio dedicated switching power supply.