Short answer: the SMSL SU-6 on measured measured performance, the SMSL SU-1 on price. The SMSL SU-6 ranks #20 of 30 DACs, rated 4.6/5, at $169.99. The SMSL SU-1 ranks #23, rated 4.5/5, at $84.99, $85 cheaper.
What the SMSL SU-6 does well: Audio Science Review measured a SINAD of 118 dB, so its noise and distortion are inaudible. The catch: It has only RCA outputs, with no balanced XLR.
What the SMSL SU-1 does well: 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-6 when measured performance outweighs the price for you, and the SMSL SU-1 when the price outweighs measured performance instead.
Looking for alternatives? See the complete Headphone Amps and DACs rankings.
Specifications Side By Side
| SMSL SU-6 | SMSL SU-1 | |
|---|---|---|
| Price | $169.99 | $84.99 |
| Ranked | #20 of 30 in DACs | #23 of 30 in DACs |
| Device Type | DAC | DAC |
| SINAD | 118 dB (measured by Audio Science Review) | 116 dB (measured by Audio Science Review) |
| Balanced Output | No | No |
| Inputs | USB, optical, coaxial, Bluetooth | USB, optical, coaxial |
| Outputs | RCA | - |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC | - |
| DAC Chip | ES9038Q2M | AK4493S |
| Dimensions | 5.5” x 1.1” x 4.1” (140 x 28 x 105 mm) | 3.8” x 1.1” x 3.1” (96 x 27 x 78 mm) |
| Weight | 0.8 lbs (350 g) | 0.4 lbs (195 g) |
| Volume Control | - | None (PC volume) |
Related Amp and DAC Comparisons
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- Topping D50 III vs SMSL SU-6
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- SMSL SU-2 vs SMSL SU-6
- SMSL SU-6 vs Soncoz LA-QXD1
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-6: $169.99 Amazon eBay
Pros: Audio Science Review measured a SINAD of 118 dB, so its noise and distortion are inaudible. It accepts USB, optical, coaxial and Bluetooth with LDAC, aptX HD and AAC, which makes it a flexible source for powered speakers or a separate amp. It is compact at 140 x 105 mm and 350 g.
Cons: It has only RCA outputs, with no balanced XLR. The SMSL SU-2 rates higher and measures cleaner at 123 dB for less. No volume control is listed, so it relies on the connected amp or speakers.
Full SMSL SU-6 review and specifications →
| Released | Nov 2021 (4 years ago) |
|---|---|
| Balanced Output | No |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC |
| DAC Chip | ES9038Q2M |
| Device Type | DAC |
| Dimensions | 5.5” x 1.1” x 4.1” (140 x 28 x 105 mm) |
| Inputs | USB, optical, coaxial, Bluetooth |
| Outputs | RCA |
| SINAD | 118 dB (measured by Audio Science Review) |
| Weight | 0.8 lbs (350 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