Short answer: the Topping D50 III. It ranks #1 of 55 DACs by measured performance (rated 4.9/5) at $229 and is still sold new; the SMSL DO300 ranks #5 (rated 4.8/5) and is discontinued, so it is only an option used.
The case for the SMSL DO300: Audio Science Review measured a SINAD of 123 dB, so its noise and distortion are inaudible and it is fully transparent. It supports aptX HD Bluetooth, which the Topping D50 III lacks. The tradeoff: It is no longer sold new, so the SMSL D400ES or Topping D70 Pro SABRE are the current picks at the same rating and SINAD.
The case for the Topping D50 III: Audio Science Review measured 123 dB SINAD, so its noise and distortion are transparent. The catch: Balanced output uses 6.35 mm TRS jacks rather than XLR, so XLR gear needs adapter cables.
Buy the Topping D50 III. It is rated higher; the SMSL DO300 is no longer sold new.
Looking for alternatives? See the complete Headphone Amps and DACs rankings.
Specifications Side By Side
| SMSL DO300 | Topping D50 III | |
|---|---|---|
| Price | Discontinued | $229.00 |
| Ranked | #5 of 55 in DACs | #1 of 55 in DACs |
| Device Type | DAC | DAC |
| SINAD | 123 dB (measured by Audio Science Review) | 123 dB (measured by Audio Science Review) |
| Inputs | USB-B, optical, coaxial, AES/EBU, I2S (HDMI), Bluetooth 5.0 | USB-C, optical, coaxial, Bluetooth |
| Outputs | RCA, XLR | RCA, 6.35 mm TRS balanced |
| Balanced Output | Yes (XLR line out) | Yes (TRS line out) |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC | SBC, LDAC |
| DAC Chip | ESS ES9039MSPRO | 2 x ES9039Q2M |
| Dimensions | 8.3” x 1.7” x 7.3” (210 x 43 x 185 mm) | 4.9” x 1” x 5.2” (125 x 26 x 131 mm) |
| Weight | 2.6 lbs (1.2 kg) | - |
| Volume Control | - | Digital (joystick, remote) |
| Equalizer | - | Yes (10-band parametric) |
Related Amp and DAC Comparisons
More top alternatives to Topping D50 III:
- Topping D50 III vs SMSL D-6S
- Topping D50 III vs SMSL DO200 MKII
- Topping D50 III vs Fosi Audio ZD3
- Topping D50 III vs SMSL D200
- Topping D50 III vs SMSL SU-6
Prices on this page were last checked October 13, 2026 at 3:17 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Amps and DACs In Full
SMSL DO300 Discontinued eBay
Pros: Audio Science Review measured a SINAD of 123 dB, so its noise and distortion are inaudible and it is fully transparent. Inputs cover USB, optical, coaxial, AES/EBU, I2S over HDMI and Bluetooth 5.0 with LDAC, aptX HD and AAC, with RCA and balanced XLR outputs for powered monitors or an amp.
Cons: It is no longer sold new, so the SMSL D400ES or Topping D70 Pro SABRE are the current picks at the same rating and SINAD. It is a DAC only, with no headphone output, and at 1.2 kg it is a full size desktop box.
Full SMSL DO300 review and specifications →
| Released | 2023 (3 years ago) |
|---|---|
| Balanced Output | Yes (XLR line out) |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC |
| DAC Chip | ESS ES9039MSPRO |
| Device Type | DAC |
| Dimensions | 8.3” x 1.7” x 7.3” (210 x 43 x 185 mm) |
| Inputs | USB-B, optical, coaxial, AES/EBU, I2S (HDMI), Bluetooth 5.0 |
| Outputs | RCA, XLR |
| SINAD | 123 dB (measured by Audio Science Review) |
| Weight | 2.6 lbs (1.2 kg) |
- Reviews, Comparisons and Sound Samples
Topping D50 III: $229.00 Amazon $229.00 eBay
Pros: Audio Science Review measured 123 dB SINAD, so its noise and distortion are transparent. It packs USB-C, optical, coaxial and LDAC Bluetooth inputs, a remote controlled volume, 10 band parametric EQ and balanced TRS outputs into a compact chassis for an amp or powered speakers. It matches the rating of the Topping D900 for a small fraction of the price.
Cons: Balanced output uses 6.35 mm TRS jacks rather than XLR, so XLR gear needs adapter cables. Bluetooth lacks aptX and AAC, offering only SBC and LDAC.
Full Topping D50 III review and specifications →
| Released | Mar 2024 (2 years ago) |
|---|---|
| Balanced Output | Yes (TRS line out) |
| Bluetooth Codecs | SBC, LDAC |
| DAC Chip | 2 x ES9039Q2M |
| Device Type | DAC |
| Dimensions | 4.9” x 1” x 5.2” (125 x 26 x 131 mm) |
| Equalizer | Yes (10-band parametric) |
| Inputs | USB-C, optical, coaxial, Bluetooth |
| Outputs | RCA, 6.35 mm TRS balanced |
| SINAD | 123 dB (measured by Audio Science Review) |
| Volume Control | Digital (joystick, remote) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons