Overview

The Loxjie A40 is a 2024 all-in-one Class D integrated amplifier built around Infineon’s MERUS MA5332MS power stage. It combines a USB DAC (Cirrus Logic CS43131 via XMOS XU316), HDMI ARC, Bluetooth 5.1 with LDAC/aptX HD, a subwoofer out, dual headphone jacks (6.35 mm and 4.4 mm), and—unusually at this size—a phono input. Rated output is 165 W ×2 into 4 Ω (THD+N <1%). Street price is 255 USD. [1][2]

Scientific Validity

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Independent lab measurements are not yet widely published. Manufacturer-published specifications list THD+N (A-weighted) at 0.003%, SNR (A-weighted) at 107 dB, and channel separation at 98 dB, alongside 165 W ×2 (4 Ω) and 85 W ×2 (8 Ω). USB supports PCM up to 32-bit/768 kHz and DSD256; MQA and MQA-CD decoding are reported over USB/S/PDIF. These figures, if met, are at or near transparent thresholds for audibility; pending third-party verification, we provisionally set scientific validity slightly above the unknown-data baseline. [1][2]

Technology Level

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The design uses current, mainstream parts (MA5332MS power stage, CS43131 DAC, XMOS XU316 USB interface, NJW1194 electronic volume) and a Qualcomm QCC5125 BT receiver supporting LDAC/aptX HD. Useful integrations include separate speaker/headphone volume memories, eight EQ presets, and five digital filters. Solid, but not indicative of proprietary breakthroughs. [2]

Cost-Performance

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Current market price is 255 USD. We looked for cheaper integrated units offering equal-or-better user functions (HDMI ARC + phono + USB DAC + BT with LDAC + dual headphone outs + sub out) and not worse core specs (e.g., THD+N around 0.003%, SNR ≥105 dB). We did not find a cheaper match. The closest mainstream alternative, SMSL AO300, offers a very similar platform (MA5332MS, CS43131, XU-316, HDMI ARC, dual HP outs, LDAC) but omits a phono input and typically sells for 289 USD. Therefore, no cheaper equivalent-or-better option exists and CP is set to 1.0. [1][3][4]

Reliability & Support

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Long-term failure-rate data and MTBF figures are not published. The architecture (switch-mode power with few moving parts) is generally robust, but the brand’s relatively short history and limited public reliability statistics keep confidence at a cautious level. We will revise when dependable multi-unit field data becomes available.

Rationality of Design Philosophy

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The A40’s feature integration is practical and user-oriented: HDMI ARC for TV, onboard phono to consolidate vinyl setups, a competent USB DAC path, dual headphone outputs, and configurable EQ/filters—without resorting to non-scientific claims. MQA/MQA-CD support is present as a format feature rather than an asserted audible upgrade. Overall, it channels cost into measurable functionality. [1][2]

Advice

If you want one compact box to handle TV, computer, Bluetooth, headphones, and a turntable, the A40 is unusually complete and powerful for the money. Its phono input makes it a convenient vinyl hub, and HDMI ARC simplifies TV hookups. If you require bullet-proof reliability data or independently verified top-tier lab numbers, monitor upcoming third-party measurements or consider more established lines at higher prices.

References

[1] Amazon – “LOXJIE A40 Digital Audio Amplifier” (specs & price). Accessed 2025-08-24. https://www.amazon.com/LOXJIE-A40-Amplifier-Headphone-Receiver/dp/B0CP27TQ2P
[2] Audiophonics – “LOXJIE A40 Class D Amplifier” (full spec, XU316/QCC5125/MQA). Accessed 2025-08-24. https://www.audiophonics.fr/en/integrated-amplifiers/loxjie-A40-p-18780.html
[3] SMSL (official) – “AO300 product page (platform details, MQA, codecs).” Accessed 2025-08-24. https://www.smsl-audio.com/portal/product/detail/id/848.html
[4] HiFiGo – “SMSL AO300 price (USD 289).” Accessed 2025-08-24. https://hifigo.com/products/smsl-ao300

(2025.8.24)