Short answer: the Topping D900 if measured performance matters most, the SMSL M400 if price matters most. The Topping D900 ranks #2 of 30 DACs, rated 4.9/5, at $1,799. The SMSL M400 ranks #13, rated 4.8/5, at $859.99, $939.01 cheaper.
Why pick the Topping D900: Audio Science Review measured 122 dB SINAD, so its noise and distortion are transparent. It supports aptX Adaptive Bluetooth, which the SMSL M400 lacks. The tradeoff: The Topping D50 III matches its rating with slightly higher measured SINAD for a small fraction of the price.
The case for the SMSL M400: Audio Science Review measured 121 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.
Buy the Topping D900 when measured performance outweighs the price for you, and the SMSL M400 when the price outweighs measured performance instead.
Looking for alternatives? See the complete Headphone Amps and DACs rankings.
Specifications Side By Side
| Topping D900 | SMSL M400 | |
|---|---|---|
| Price | $1,799.00 | $859.99 |
| Ranked | #2 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-B, USB-C, optical x2, coaxial x2, AES, I2S, Bluetooth | USB, optical, coaxial, I2S, Bluetooth |
| Outputs | XLR (line out), XLR (preamp out) | RCA, XLR |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, aptX Adaptive, LDAC | UAT, LDAC, aptX HD, aptX, AAC, SBC |
| DAC Chip | Discrete PSRM 1-bit module | AK4499EQ |
| Volume Control | Hardware knob | Digital (knob and remote), fixed or variable |
| Equalizer | Yes (10-band parametric) | - |
| Dimensions | 13” x 2.2” x 8.3” (330 x 57 x 210 mm) | 8.7” x 1.7” x 8.5” (220 x 43 x 215 mm) |
| Weight | 5.6 lbs (2,520 g) | 3.4 lbs (1,530 g) |
Related Amp and DAC Comparisons
How Topping D900 compares with other leading options:
- Topping D900 vs SMSL SU-10
- Topping D900 vs Topping D90 III Sabre
- Topping D900 vs SMSL VMV D2R
- Topping D900 vs Topping Centaurus
- Topping D900 vs Chord Qutest
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
Topping D900: $1,799.00 Amazon eBay
Pros: Audio Science Review measured 122 dB SINAD, so its noise and distortion are transparent. It has a huge input set, including USB, two optical, two coaxial, AES, I2S and Bluetooth with LDAC and aptX Adaptive, plus a volume knob, 10 band parametric EQ and an XLR preamp output for powered speakers.
Cons: The Topping D50 III matches its rating with slightly higher measured SINAD for a small fraction of the price. Outputs are XLR only with no RCA, and at 2,520 g it is a large unit.
Full Topping D900 review and specifications →
| Released | Jun 2025 (1 year ago) |
|---|---|
| Balanced Output | Yes (XLR line out) |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, aptX Adaptive, LDAC |
| DAC Chip | Discrete PSRM 1-bit module |
| Device Type | DAC |
| Dimensions | 13” x 2.2” x 8.3” (330 x 57 x 210 mm) |
| Equalizer | Yes (10-band parametric) |
| Inputs | USB-B, USB-C, optical x2, coaxial x2, AES, I2S, Bluetooth |
| Outputs | XLR (line out), XLR (preamp out) |
| SINAD | 122 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
| Weight | 5.6 lbs (2,520 g) |
- 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