SMSL A300
A budget Class D amplifier offering BTL bridging capability and Bluetooth connectivity, but hampered by modest measured performance that falls short of equally-priced competitors.
Overview
The SMSL A300 is a compact Class D power amplifier featuring dual-channel operation (165W×2 at 4Ω) or BTL single-channel mode (330W at 4-8Ω). Based on the Infineon MA5332MS amplifier chip with NJW1194 digital volume control, it includes Bluetooth 5.0 connectivity, analog RCA inputs, and built-in high-pass filtering for 2.1 system integration. The A300 positions itself as an affordable entry into SMSL’s amplifier lineup at approximately 200 USD.
Scientific Validity
\[\Large \text{0.6}\]Audio Science Review measurements reveal moderate performance with SINAD around 80 dB (4Ω load), placing the A300 in the “competent but average” category [1]. Manufacturer specifications state THD+N of 0.004% at rated power, SNR of 103 dB, and channel separation of 85 dB [2]. While these specifications appear reasonable, independent third-party measurements show the amplifier falling short of transparent performance levels. Overall, performance sits between problematic and transparent levels across key metrics.
Technology Level
\[\Large \text{0.6}\]The A300 employs standard Infineon MA5332MS Class D amplification with NJW1194 digital volume control, representing competent but unremarkable engineering. BTL capability and integrated high-pass filtering for subwoofer integration demonstrate practical feature implementation. However, the underlying technology is widely available and not particularly advanced compared to current industry standards. The design achieves basic functionality without pushing technical boundaries or introducing innovative solutions.
Cost-Performance
\[\Large \text{0.4}\]Representative current market price for A300 is 195.99 USD (purchase link on the official page) [2]. As an equal-or-better comparator from a user perspective for typical 2.0 stereo use, the Fosi Audio BT20A Pro offers Bluetooth input, pre-out with volume control, and tone controls, with superior published distortion/SNR figures [3]. CP calculation: 79.99 USD ÷ 195.99 USD = 0.408 → rounded to 0.4.
Reliability & Support
\[\Large \text{0.6}\]SMSL provides standard manufacturer warranty and support through established distribution channels. The company maintains reasonable customer service for the budget audio segment, though no exceptional reliability data or extended warranty programs distinguish the A300. Firmware updates are not applicable to this analog amplifier design. Build quality appears adequate for the price point without notable quality control issues reported.
Rationality of Design Philosophy
\[\Large \text{0.5}\]The A300’s design philosophy focuses on basic amplification functionality with practical features like BTL mode and Bluetooth connectivity. However, the engineering approach does not prioritize achieving transparent performance levels that would justify dedicated amplifier over general-purpose alternatives. The measured performance fails to demonstrate meaningful advantages over smartphone-connected DAC/amplifier combinations in the same price range. While not employing objectionable “audiophile” marketing claims, the design lacks the technical advancement needed to justify its existence as dedicated audio equipment.
Advice
Consider the Fosi Audio V3 or BT20A Pro as superior alternatives offering better measured performance at lower cost. The A300’s BTL capability may appeal to users requiring single-channel high-power operation, but standard stereo applications would benefit from higher-performing alternatives. For users specifically requiring SMSL brand preference or integrated Bluetooth with physical volume control, the A300 provides basic functionality. However, the combination of smartphone plus external DAC/amplifier would typically deliver superior performance and greater flexibility at comparable cost.
References
[1] Audio Science Review, “SMSL A300 Stereo Amplifier Review”, https://www.audiosciencereview.com/forum/index.php?threads/smsl-a300-stereo-amplifier-review.46742/, accessed 2025-08-13, SINAD measurement (approx. 80 dB, 4Ω load)
[2] SMSL Audio, “A300 Power Amplifier (Product Page/Manual)”, https://www.smsl-audio.com/portal/product/detail/id/792.html, accessed 2025-08-13, manufacturer specifications and purchase links (AliExpress link showing 195.99 USD)
[3] Fosi Audio, “BT20A Pro 2 Channel Bluetooth Power Amplifier”, https://fosiaudio.com/products/bt20a-pro-2-channel-bluetooth-power-amplifier, accessed 2025-08-13, price 79.99 USD and published specifications (THD+N ≤ 0.005%, SNR ≥ 108 dB)
(2025.8.13)