Short answer: the SMSL D400 Pro. Both are rated 4.8/5 (#10 and #13 of 30 DACs), and the SMSL D400 Pro costs $728.20 against $859.99 for the SMSL M400, with the ratings tied, the lower price decides it.
The case for the SMSL D400 Pro: Audio Science Review measured 122 dB SINAD, so its noise and distortion are inaudible. The catch: It is a DAC only, so you need a separate headphone amp or powered speakers.
The case for the SMSL M400: Audio Science Review measured 121 dB SINAD, so its noise and distortion are inaudible. The tradeoff: It is a DAC only, so you need a separate headphone amp or powered speakers.
Buy the SMSL D400 Pro. Both are rated the same, and it costs $131.79 less than the SMSL M400.
Still deciding? The full Headphone Amps and DACs rankings cover every ranked option.
Specifications Side By Side
| SMSL D400 Pro | SMSL M400 | |
|---|---|---|
| Price | $728.20 | $859.99 |
| Ranked | #10 of 30 in DACs | #13 of 30 in DACs |
| Device Type | DAC | DAC |
| SINAD | 122 dB (measured by Audio Science Review) | 121 dB (measured by Audio Science Review) |
| Balanced Output | Yes (XLR line out) | Yes (XLR line out) |
| Inputs | USB, optical, coaxial, I2S, AES, Bluetooth | USB, optical, coaxial, I2S, Bluetooth |
| Outputs | RCA, XLR | RCA, XLR |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC | UAT, LDAC, aptX HD, aptX, AAC, SBC |
| DAC Chip | AK4499EX + AK4191EQ | AK4499EQ |
| Dimensions | 10” x 1.8” x 7.4” (254 x 46 x 189 mm) | 8.7” x 1.7” x 8.5” (220 x 43 x 215 mm) |
| Weight | 4.2 lbs (1.9 kg) | 3.4 lbs (1,530 g) |
| Volume Control | - | Digital (knob and remote), fixed or variable |
Related Amp and DAC Comparisons
More top alternatives to SMSL D400 Pro:
- SMSL D400 Pro vs SMSL SU-10
- SMSL D400 Pro vs SMSL RAW Pro-DAC1
- SMSL D400 Pro vs SMSL VMV D1se2
- SMSL D400 Pro vs Topping D70 Pro SABRE
- SMSL D400 Pro vs Topping D90 III Sabre
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 D400 Pro: $728.20 HiFiGo eBay
Pros: Audio Science Review measured 122 dB SINAD, so its noise and distortion are inaudible. It has a wide range of inputs, including USB, optical, coaxial, I2S, AES and Bluetooth with LDAC, aptX HD, aptX, AAC and SBC, and outputs to amps or powered speakers over RCA or balanced XLR.
Cons: It is a DAC only, so you need a separate headphone amp or powered speakers. The Topping D70 Pro SABRE earns the same rating and measured slightly cleaner for less, and the SMSL DO200 Pro matches its SINAD for much less. No volume control is listed, so it may not work as a preamp for active speakers.
Full SMSL D400 Pro review and specifications →
| Balanced Output | Yes (XLR line out) |
|---|---|
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC |
| DAC Chip | AK4499EX + AK4191EQ |
| Device Type | DAC |
| Dimensions | 10” x 1.8” x 7.4” (254 x 46 x 189 mm) |
| Inputs | USB, optical, coaxial, I2S, AES, Bluetooth |
| Outputs | RCA, XLR |
| SINAD | 122 dB (measured by Audio Science Review) |
| Weight | 4.2 lbs (1.9 kg) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
SMSL M400: $859.99 HiFiGo eBay
Pros: Audio Science Review measured 121 dB SINAD, so its noise and distortion are inaudible. It accepts USB, optical, coaxial, I2S and Bluetooth with UAT, LDAC, aptX HD, aptX, AAC and SBC, and drives amps or powered speakers through RCA or balanced XLR outputs. A volume knob and remote with fixed or variable output let it work as a preamp for active speakers.
Cons: It is a DAC only, so you need a separate headphone amp or powered speakers. Several rivals with the same rating measured slightly cleaner for less, including the Topping D70 Pro SABRE and the SMSL RAW Pro-DAC1.
Full SMSL M400 review and specifications →
| Balanced Output | Yes (XLR line out) |
|---|---|
| Bluetooth Codecs | UAT, LDAC, aptX HD, aptX, AAC, SBC |
| DAC Chip | AK4499EQ |
| Device Type | DAC |
| Dimensions | 8.7” x 1.7” x 8.5” (220 x 43 x 215 mm) |
| Inputs | USB, optical, coaxial, I2S, Bluetooth |
| Outputs | RCA, XLR |
| SINAD | 121 dB (measured by Audio Science Review) |
| Volume Control | Digital (knob and remote), fixed or variable |
| Weight | 3.4 lbs (1,530 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons