Short answer: the SMSL DO400. It ranks #1 of 43 DAC and headphone amp combos by measured performance, rated 4.9/5, at $499. The Aune X1s GT ranks #11, rated 4.8/5, at $319, $180 cheaper, not enough of a saving to outweigh the sound-quality gap.
Why pick the SMSL DO400: Audio Science Review measured 123 dB SINAD, so its noise and distortion are transparent. The catch: It costs more than the D&A Alpha and SMSL RAW-MDA1, which share its rating and also measure transparent.
Why pick the Aune X1s GT: Audio Science Review measured 114 dB SINAD, which keeps noise and distortion clean for nearly all listening. The tradeoff: It costs more than the Topping DX3 Pro+, which rates the same with higher measured SINAD and more rated power.
Buy the SMSL DO400. It is rated higher, and the $180 saving on the Aune X1s GT is not enough to make up the difference.
Still deciding? The full Headphone Amps and DACs rankings cover every ranked option.
Specifications Side By Side
| SMSL DO400 | Aune X1s GT | |
|---|---|---|
| Price | $499.00 | $319.00 |
| Ranked | #1 of 43 in DAC and Headphone Amp Combos | #11 of 43 in DAC and Headphone Amp Combos |
| Device Type | DAC and headphone amp | DAC and headphone amp |
| SINAD | 123 dB (measured by Audio Science Review) | 114 dB (measured by Audio Science Review) |
| Output Power (32 ohms) | 3,000 mW (manufacturer rated) | 1,200 mW (manufacturer rated, balanced) |
| Output Power (300 ohms) | 700 mW (manufacturer rated) | - |
| Headphone Outputs | 6.35 mm, 4.4 mm balanced, 4-pin XLR balanced | 6.35 mm, 4.4 mm balanced |
| Balanced Output | Yes (4.4 mm, 4-pin XLR, XLR line out) | Yes (4.4 mm) |
| Inputs | USB, optical, coaxial, AES/EBU, I2S, Bluetooth | USB, optical, coaxial, 10 MHz clock (BNC) |
| Outputs | RCA, XLR | RCA line out, RCA pre out |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC | - |
| DAC Chip | ES9039MSPRO | - |
| Dimensions | 9.6” x 1.7” x 7.3” (245 x 42 x 186 mm) | - |
| Weight | 3.2 lbs (1,450 g) | - |
| Volume Control | - | Hardware knob |
Related Amp and DAC Comparisons
More top alternatives to SMSL DO400:
- D&A Alpha vs SMSL DO400
- SMSL DO400 vs Topping DX5 II
- D&A Alpha Pro vs SMSL DO400
- SMSL DO400 vs Topping G5
- SMSL DO400 vs JDS Labs Element IV
Prices on this page were last checked October 11, 2026 at 4:59 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 DO400: $499.00 Amazon eBay
Pros: Audio Science Review measured 123 dB SINAD, so its noise and distortion are transparent. A rated 3 W into 32 ohms and 700 mW into 300 ohms drives nearly any headphone, through 6.35 mm, 4.4 mm or 4-pin XLR outputs. Inputs cover USB, optical, coaxial, AES/EBU, I2S and LDAC Bluetooth, with RCA and XLR outputs for powered speakers.
Cons: It costs more than the D&A Alpha and SMSL RAW-MDA1, which share its rating and also measure transparent. At 1,450 g it is a full size desktop unit.
Full SMSL DO400 review and specifications →
| Balanced Output | Yes (4.4 mm, 4-pin XLR, XLR line out) |
|---|---|
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC |
| DAC Chip | ES9039MSPRO |
| Device Type | DAC and headphone amp |
| Dimensions | 9.6” x 1.7” x 7.3” (245 x 42 x 186 mm) |
| Headphone Outputs | 6.35 mm, 4.4 mm balanced, 4-pin XLR balanced |
| Inputs | USB, optical, coaxial, AES/EBU, I2S, Bluetooth |
| Output Power (300 ohms) | 700 mW (manufacturer rated) |
| Output Power (32 ohms) | 3,000 mW (manufacturer rated) |
| Outputs | RCA, XLR |
| SINAD | 123 dB (measured by Audio Science Review) |
| Weight | 3.2 lbs (1,450 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Aune X1s GT: $319.00 Aune official store eBay
Pros: Audio Science Review measured 114 dB SINAD, which keeps noise and distortion clean for nearly all listening. Aune rates it at 1,200 mW into 32 ohms from the 4.4 mm balanced jack, enough for most planar magnetic headphones, and it takes USB, optical and coaxial inputs plus an external 10 MHz clock. RCA line and preamp outputs let it feed powered speakers too.
Cons: It costs more than the Topping DX3 Pro+, which rates the same with higher measured SINAD and more rated power. The SMSL RAW-MDA1 rates higher for less, and there is no Bluetooth input.
Full Aune X1s GT review and specifications →
| Released | Oct 2021 (5 years ago) |
|---|---|
| Balanced Output | Yes (4.4 mm) |
| Device Type | DAC and headphone amp |
| Headphone Outputs | 6.35 mm, 4.4 mm balanced |
| Inputs | USB, optical, coaxial, 10 MHz clock (BNC) |
| Output Power (32 ohms) | 1,200 mW (manufacturer rated, balanced) |
| Outputs | RCA line out, RCA pre out |
| SINAD | 114 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons