Short answer: the SMSL SU-2. It ranks #18 of 30 DACs by measured performance, rated 4.7/5, at $99.99. The SMSL SU-1 ranks #23, rated 4.5/5, at $84.99, $15 cheaper, not enough of a saving to outweigh the sound-quality gap.
The case for the SMSL SU-2: Audio Science Review measured 123 dB SINAD, so its noise and distortion are transparent. The catch: There is no USB input listed, so a computer needs a separate USB to digital converter.
The case for the SMSL SU-1: Audio Science Review measured a SINAD of 116 dB, so its noise and distortion are inaudible. The catch: It has no volume control of its own, so level must be set on the computer or the downstream amp, and there is no balanced output or Bluetooth.
Buy the SMSL SU-2. It is rated higher, and the $15 saving on the SMSL SU-1 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 SU-2 | SMSL SU-1 | |
|---|---|---|
| Price | $99.99 | $84.99 |
| Ranked | #18 of 30 in DACs | #23 of 30 in DACs |
| Device Type | DAC | DAC |
| SINAD | 123 dB (measured by Audio Science Review) | 116 dB (measured by Audio Science Review) |
| Balanced Output | Yes (XLR line out) | No |
| Inputs | AES/EBU, optical, coaxial | USB, optical, coaxial |
| Outputs | RCA, XLR | - |
| DAC Chip | ES9039Q2M | AK4493S |
| Dimensions | 5.9” x 1.7” x 5.2” (150 x 42.5 x 133.1 mm) | 3.8” x 1.1” x 3.1” (96 x 27 x 78 mm) |
| Weight | 1.2 lbs (533 g) | 0.4 lbs (195 g) |
| Volume Control | - | None (PC volume) |
Related Amp and DAC Comparisons
More top alternatives to SMSL SU-2:
- Fosi Audio ZD3 vs SMSL SU-2
- SMSL SU-2 vs SMSL SU-6
- SMSL SU-2 vs SMSL PS200 PRO
- SMSL SU-2 vs Topping E30 II Lite
- SMSL SU-2 vs Fosi Audio Q6
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 SU-2: $99.99 Amazon eBay
Pros: Audio Science Review measured 123 dB SINAD, so its noise and distortion are transparent. It sends RCA and XLR outputs to an amp or powered speakers, and accepts AES/EBU, optical and coaxial digital sources. It matches the rating of the Topping Centaurus and measures cleaner for a small fraction of the price.
Cons: There is no USB input listed, so a computer needs a separate USB to digital converter. It has no Bluetooth or volume control, and the SMSL D-6S rates higher with USB and LDAC Bluetooth for more money.
Full SMSL SU-2 review and specifications →
| Released | Jan 2026 (9 months ago) |
|---|---|
| Balanced Output | Yes (XLR line out) |
| DAC Chip | ES9039Q2M |
| Device Type | DAC |
| Dimensions | 5.9” x 1.7” x 5.2” (150 x 42.5 x 133.1 mm) |
| Inputs | AES/EBU, optical, coaxial |
| Outputs | RCA, XLR |
| SINAD | 123 dB (measured by Audio Science Review) |
| Weight | 1.2 lbs (533 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
SMSL SU-1: $84.99 Amazon eBay
Pros: Audio Science Review measured a SINAD of 116 dB, so its noise and distortion are inaudible. It is a compact, inexpensive DAC with USB, optical and coaxial inputs that connects to an amp or powered speakers.
Cons: It has no volume control of its own, so level must be set on the computer or the downstream amp, and there is no balanced output or Bluetooth. The SMSL PS200 PRO measured cleaner at 120 dB for about the same price, and the SMSL SU-2 rates higher for only a little more.
Full SMSL SU-1 review and specifications →
| Released | 2023 (3 years ago) |
|---|---|
| Balanced Output | No |
| DAC Chip | AK4493S |
| Device Type | DAC |
| Dimensions | 3.8” x 1.1” x 3.1” (96 x 27 x 78 mm) |
| Inputs | USB, optical, coaxial |
| SINAD | 116 dB (measured by Audio Science Review) |
| Volume Control | None (PC volume) |
| Weight | 0.4 lbs (195 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons