The SMSL AS400 combines a Cirrus Logic CS43131 DAC, an Infineon MA5332MS Class D amplifier rated 165W x 2 into 4Ω, an MM phono stage and 4.4mm and 6.35mm headphone jacks, with USB, HDMI ARC, optical, coaxial, line, phono and Bluetooth inputs. It suits a desk or living-room system that runs passive speakers, a turntable and a TV from one box.
Who the SMSL AS400 is for
Vinyl listening: A built-in low-noise MM phono preamp and a grounding terminal let a moving-magnet turntable plug straight in.
TV sound: The HDMI ARC input carries TV audio over one cable, with optical and coaxial inputs for TVs without ARC.
Passive speakers and a sub: It is rated 165W x 2 into 4Ω or 85W x 2 into 8Ω at 0.003% THD+N, and a subwoofer pre-out adds a powered sub for 2.1.
Computer and phone playback: XMOS XU-316 USB handles PCM up to 32-bit/768kHz and DSD256 with MQA decoding, and Bluetooth supports LDAC, aptX HD, aptX, AAC and SBC.
Headphones: 4.4mm and 6.35mm jacks sit on the front panel, and the output menu switches between speakers and headphones.
Skip it if: you use a moving-coil (MC) cartridge or want HDMI eARC; the phono stage is for MM cartridges and the HDMI input is ARC.
SMSL AS400 key specs
Chips: Cirrus Logic CS43131 DAC; Infineon MA5332MS Class D amp; JRC NJW1194A volume; XMOS XU-316 USB
Output power: 165W x 2 (4Ω), 85W x 2 (8Ω)
THD+N / SNR / separation: 0.003% / 107dB / 98dB
Inputs: USB, HDMI ARC, optical, coaxial, RCA line, MM phono, Bluetooth (LDAC, aptX HD, aptX, AAC, SBC)
Outputs: Speaker terminals, subwoofer pre-out, 4.4mm and 6.35mm headphone jacks
Formats: USB PCM 44.1–768kHz up to 32-bit, DSD up to DSD256; optical/coaxial PCM 44.1–192kHz, DSD64 (DoP); MQA and MQA-CD
Sound settings: 8 EQ modes incl. SMSL SDB; bass and treble ±9dB; 5 digital filters
Power: Built-in switching supply, AC 100–240V; 40W at normal volume
Size, weight and colors: 210.4 × 46 × 254mm (W × H × D); 1.568kg; Silver or Black
In the box: RC-8A remote, AC power cord, USB cable, HDMI cable, Bluetooth antenna
Genuine SMSL stock. Free shipping on every order, 45-day returns.
SMSL AS400 vs similar options
vs SMSL AO300 PRO: Adds HDMI eARC with CEC on the same CS43131 and MA5332MS chips for $11–12 less; pick the AS400 for its built-in MM phono preamp.
vs Fosi Audio MC351: Costs about $36 less with dual TPA3255 chips and passive-subwoofer binding posts; pick the AS400 for an MM phono stage, HDMI ARC, LDAC Bluetooth and 4.4mm/6.35mm headphone jacks.
Yes. Every unit we sell is genuine and brand-new, shipped in its original packaging, and backed by our 1-year TonePier warranty and 45-day returns.
Where does my order ship from, and how long does it take?
Every order ships from our warehouse in China, with full tracking, and most orders ship within 3 business days. Shipping is free on every order; most US orders arrive within 7–15 business days and most orders to other countries within 7–20 business days — see our shipping policy for details.
What if it isn't for me?
You get 45 days to decide. Keep the packaging, keep it in like-new condition, and send it back for a refund. Ear tips unsealed for hygiene reasons are fine — we expect you to actually listen.
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