Overview

The SMSL DA-9 is a Bluetooth 5.0-compatible Class D power amplifier developed by Chinese company SMSL Audio. It incorporates a German Infineon Class D amplifier chip and a Japanese NJRC electronic volume control chip NJW1194, achieving 90W×2 (4Ω) output. In addition to aptX codec-compatible Bluetooth connectivity, it was designed as a multifunctional integrated amplifier with XLR balanced and RCA inputs. However, it is currently discontinued and difficult to purchase new.

Scientific Validity

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The SMSL DA-9’s measurement performance shows excellent figures approaching transparency. Third-party measurements, such as those from Audio Science Review (ASR), have confirmed its excellent performance with a SINAD of 93dB (equivalent to a THD+N of approx. 0.0022%) and an SNR of over 111dB, sufficiently backing up the official specifications. The channel separation, measured at around -100dB, also significantly exceeds the transparency standard of -70dB, virtually eliminating crosstalk-induced sound quality degradation. However, the score is 0.8 as measurements have shown that its performance varies slightly with load impedance, meaning it does not achieve perfect transparency.

Technology Level

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The DA-9’s technical configuration includes elements that exceed industry standards for its time. The Class D design using the German Infineon MA12070 chip was an advanced approach. The adoption of the Japanese NJRC NJW1194 electronic volume control chip enables precise volume adjustment and low distortion. The full-balanced circuit design also contributes to reducing signal distortion. However, from current technical standards, newer chipsets and design methodologies are available, and its technical advantages have relatively declined. Differentiation through proprietary technology or patents is also limited.

Cost-Performance

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Against the DA-9’s original price of 250 USD, the higher-performing Topping PA3s is available for 149 USD. The PA3s offers superior performance, with an ASR-measured SINAD of 104dB compared to the DA-9’s 93dB, while providing equivalent functionality in terms of power output (80W×2@4Ω) and I/O (TRS balanced and RCA). The calculation is 149 USD ÷ 250 USD = 0.596, which rounds to a score of 0.6. The DA-9’s poor availability due to being discontinued further diminishes its cost-performance in the current market.

Reliability & Support

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While SMSL Audio has a certain track record as a Chinese audio manufacturer, the fact that the DA-9 is already discontinued raises concerns about long-term support. The warranty period was a standard one year, but obtaining parts and repair services may now be difficult. Some users on ASR forums have reported issues with the device freezing at the startup screen, a problem that was hoped to be solved by a firmware update, but support is no longer expected due to its discontinuation. The short product lifecycle is a challenge.

Rationality of Design Philosophy

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The DA-9’s design philosophy adopts the rational approach of combining high-efficiency Class D technology with Bluetooth connectivity. The full-balanced circuit design, which contributes to improved measurement performance, and the selection of high-quality chipsets are scientifically grounded decisions. Additional features like eight EQ modes and a subwoofer output also enhance practicality. However, from current technical standards, more efficient and lower-cost implementation methods exist. Particularly when compared to general-purpose devices (smartphone + external DAC/amplifier), the necessity of it as dedicated audio equipment is becoming less apparent.

Advice

While the SMSL DA-9 was a technically excellent product at its launch, it is now discontinued and not recommended for purchase. For those seeking equivalent functionality and superior measured performance, the Topping PA3s (149 USD) is the most rational choice. The PA3s offers better measured performance than the DA-9 at a lower price. If you require the all-in-one functionality of a built-in DAC, the Loxjie A30 (around 190 USD) is an option. For those on a strict budget, the Fosi Audio V3 (from around 70 USD) could be considered. However, the PA3s provides the best balance of performance and price. Considering the end-of-support risk for used DA-9 units, purchasing a current product is the wiser decision.

(2025.8.1)