Overview

The SMSL DL300 is a desktop DAC/headphone amplifier using AKM’s AK4191 digital filter/modulator with the flagship AK4499EX DAC chips in a dual-mono configuration. It supports up to PCM 32-bit/768kHz, native DSD512, full MQA/MQA-CD decoding, Bluetooth 5.1 with LDAC/aptX HD, USB/optical/coaxial/I²S inputs, and both 6.35mm SE and 4.4mm balanced headphone outputs; balanced and single-ended line outs are provided (5 Vrms XLR, 2.5 Vrms RCA) [1][2].

Scientific Validity

\[\Large \text{0.9}\]

Manufacturer specifications report DAC THD+N of 0.00006% (-124 dB, unweighted), headphone-amp THD+N of 0.0001% (-120 dB, unweighted), dynamic range/SNR up to 132 dB (line) and 126 dB (headamp), and headphone output power of 2×1 W into 32 Ω (2×2 W into 16 Ω). With flat response and very low noise/distortion, these values comfortably clear transparency thresholds for audibility in DAC/amp applications. As third-party measurements remain limited at the time of writing, the above are clearly labeled manufacturer figures and will be superseded as independent data emerges [1][2].

Technology Level

\[\Large \text{0.8}\]

The DL300 pairs AKM’s current flagship AK4499EX with AK4191 and an XMOS XU-316 USB interface, integrates LDAC-capable Bluetooth, I²S input, selectable PCM filters, “sound color” options, 2-step gain, and full MQA decode. The implementation reflects competent, up-to-date engineering across digital, clocking, and I/O without novel architectures beyond established best practices [1][2].

Cost-Performance

\[\Large \text{0.7}\]

Market price for the DL300 is 449 USD (official store) [3]. The cheapest equivalent-or-better all-in-one we identified is the Topping DX5 II at 299 USD (official store). It offers equal or better user-visible functions (USB/coax/optical, Bluetooth 5.1 with LDAC, balanced/SE headphone outs, pre-out) and manufacturer-published performance (THD+N @1 kHz <0.00006% (A-wt), SNR/DNR 133 dB, and up to 2×6.4 W into 32 Ω balanced), which meets or exceeds the DL300 on core metrics [4][5][6].
Calculation (explicit): 299 ÷ 449 = 0.666… → rounded to one decimal place = 0.7.

Reliability & Support

\[\Large \text{0.6}\]

The official shop states a one-year factory warranty, which is below the 2-year baseline some brands offer, and no extended support commitments are advertised. Construction is solid-state with few wear components, and global distribution exists via dealers, but verified long-term failure data and firmware update cadence are not clearly documented [3][1].

Rationality of Design Philosophy

\[\Large \text{0.7}\]

The product targets transparent playback through modern delta-sigma conversion, robust USB implementation, and clean headphone drive, avoiding pseudo-scientific claims. The inclusion of usability features (Bluetooth, gain steps, filters) is rational. However, given equally transparent competitors with stronger output/published specs at lower cost, the value proposition relies more on brand/form-factor preference than uniquely rational performance leadership [1][4][5].

Advice

If you want an AKM-based desktop all-in-one with I²S, full MQA decode, and balanced/SE headphone outs, the DL300 is a capable, transparent choice. If maximum measurable headroom and minimum spend are priorities, the Topping DX5 II offers equal-or-better published performance, more amplifier power, and lower price. Choose the DL300 for its specific feature mix and UI; choose the DX5 II to prioritize raw price/performance [3][4][5].

References

[1] SMSL – DL300 User Manual (Ver.1.0). Specs incl. THD+N (UN-WTD), DNR/SNR, line-out voltage, headphone power, codecs. Accessed 2025-08-28. https://www.smsl-audio.com/upload/portal/download/DL300Manual.pdf
[2] SMSL – DL300 product page. Features: AK4191+AK4499EX, XU-316, MQA/MQA-CD, BT 5.1 LDAC/aptX HD, I²S. Accessed 2025-08-28. https://www.smsl-audio.com/portal/product/detail/id/851.html
[3] SMSL SHOP (official) – DL300 price & warranty. 449 USD; “Factory warranty One-Year.” Accessed 2025-08-28. https://smsl.shop/products/dl300
[4] TOPPING Store (official) – DX5 II product page & price. 299 USD. Accessed 2025-08-28. https://www.topping.store/products/topping-dx5-ii-hi-res-dac-headphone-amp-combo
[5] APOS Audio – DX5 II highlights/specs. THD+N <0.00006% (A-wt @1 kHz), SNR/DNR 133 dB, BT 5.1 LDAC, USB XU316. Accessed 2025-08-28. https://apos.audio/products/topping-dx5-ii-dac-amp
[6] Shenzhenaudio – DX5 II specifications. Headphone output power (e.g., 2×7600 mW @16 Ω), architecture details. Accessed 2025-08-28. https://shenzhenaudio.com/products/topping-dx5-ii-dual-es9039q2m-desktop-dac-headphone-amplifier

(2025.8.28)