SMSL has introduced the AS400, an integrated amplifier designed to bring loudspeaker amplification, digital conversion, vinyl playback, Bluetooth and headphone listening together in one compact aluminum enclosure. Its extensive input selection includes USB-C, HDMI ARC and an MM phono stage, while rated output reaches 2 x 165 watts into 4 ohms.
Stereo amplification and high-resolution conversion
The AS400 is built around an Infineon MA5332MS amplifier module. It delivers a specified 2 x 165 watts into a 4-ohm load, dropping to 2 x 85 watts into 8 ohms. Loudspeakers connect through rear-panel binding posts, and an RCA output allows an active subwoofer to be added for a 2.1-channel configuration.
Digital conversion is handled by a Cirrus Logic CS43131 DAC working alongside an XMOS XU-316 USB interface. The amplifier supports PCM playback at resolutions up to 32-bit/768 kHz, as well as DSD256. MQA and MQA-CD decoding are also included.
SMSL specifies total harmonic distortion plus noise of 0.003%, a signal-to-noise ratio of 107 dB and channel separation of 98 dB. Input sensitivity is listed as 280 mV with a 22-kilohm input impedance. These figures accompany protection circuits intended to guard against overheating and overload.
Inputs for computers, televisions and turntables
The wired input selection covers USB-C, optical Toslink, coaxial digital and analog RCA sources. USB compatibility is listed for Windows 7, 8, 8.1, 10 and 11, along with macOS and Linux systems.
An HDMI ARC input enables the AS400 to receive audio from a compatible television. This gives the amplifier a direct role in a two-channel television or home cinema setup without requiring a separate AV receiver. The subwoofer output can extend that arrangement into a 2.1-channel system.
For vinyl playback, SMSL has fitted an MM phono stage. A compatible moving-magnet turntable can therefore connect directly to the amplifier rather than relying on an external phono preamplifier. A standard RCA line input remains available for other analog components.
Bluetooth and dual headphone connections
Wireless playback is provided through Bluetooth, with support for LDAC, aptX HD, AAC and SBC codecs. The range of codecs accommodates compatible mobile devices across different platforms while providing an alternative to the AS400’s physical digital and analog connections.
Headphone users receive two front-panel options. A 4.4 mm balanced output sits alongside a conventional 6.35 mm connection, allowing the amplifier to work with a wider variety of headphone cables and terminations. SMSL has not provided separate headphone output-power figures in the supplied specifications.
Compact aluminum construction and controls
The AS400 measures 210.4 x 46 x 254 mm and weighs 1.568 kg. Its aluminum-alloy chassis uses CNC machining, anodizing and shaped edge finishing. An integrated display presents operating information, while control is available from a multifunction button or the included infrared remote.
Gold-plated connectors are used in the design, and the amplifier incorporates a dedicated power supply developed for audio equipment. It accepts 100–240 V AC power and has a stated consumption of 40 watts at average listening volume.
The AS400 has been listed through AliExpress, although detailed regional availability information was not provided. No USD price was included in the supplied product information.
With speaker and headphone outputs, HDMI ARC, MM phono playback, high-resolution USB support and multiple Bluetooth codecs, the SMSL AS400 is positioned as a versatile centerpiece for a compact stereo or 2.1-channel system.
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