Short answer: the D&A Alpha Pro. It ranks #5 of 43 DAC and headphone amp combos by measured performance, rated 4.9/5, at $699; the Gustard A20H ranks #25, rated 4.2/5, and costs $752, so there is little reason to consider the other one.
The D&A Alpha Pro is the better-sounding option. Audio Science Review measured a SINAD of 121 dB, so its noise and distortion are inaudible. Watch for: It costs far more than the Topping DX1 II, which rates the same and measures the same 121 dB SINAD.
What the Gustard A20H does well: A rated 2.4 W balanced into 32 ohms and 264 mW into 300 ohms is enough for planar magnetic and high impedance headphones alike. The catch: Its 103 dB SINAD trails many cheaper rivals, and the Tanchjim Luna rates higher with cleaner measurements for a small fraction of the price.
Buy the D&A Alpha Pro. It is rated higher than the Gustard A20H and costs less, which makes it the one to get unless you need something the other one does better.
Still deciding? The full Headphone Amps and DACs rankings cover every ranked option.
Specifications Side By Side
| D&A Alpha Pro | Gustard A20H | |
|---|---|---|
| Price | $699.00 | $752 |
| Ranked | #5 of 43 in DAC and Headphone Amp Combos | #25 of 43 in DAC and Headphone Amp Combos |
| Device Type | DAC and headphone amp | DAC and headphone amp |
| SINAD | 121 dB (measured by Audio Science Review) | 103 dB (measured by Audio Science Review) |
| Output Power (32 ohms) | 6,000 mW (manufacturer rated) | 2,400 mW (manufacturer rated, balanced) |
| Output Power (300 ohms) | 700 mW (manufacturer rated) | 264 mW (manufacturer rated, balanced) |
| Headphone Outputs | 6.35 mm, 4.4 mm balanced, 4-pin XLR balanced | - |
| Balanced Output | Yes (4.4 mm, 4-pin XLR, XLR line out) | Yes (balanced headphone output, XLR line out) |
| Inputs | USB, optical, coaxial, Bluetooth, RCA | USB, I2S (HDMI), AES/EBU, coaxial, optical |
| Outputs | RCA, XLR | RCA, XLR |
| Bluetooth Codecs | SBC, AAC, aptX, aptX HD, LDAC | - |
| DAC Chip | ES9039MSPRO | 2 x AK4497EQ |
| Volume Control | Hardware knob | Relay attenuator (60 steps) |
| Dimensions | 8.9” x 2.2” x 7.8” (225 x 55 x 199.3 mm) | 13” x 2.6” x 10.2” (330 x 65 x 260 mm) |
| Weight | 3.9 lbs (1,760 g) | 13.2 lbs (6 kg) |
Related Amp and DAC Comparisons
More worthwhile head-to-heads for D&A Alpha Pro:
- D&A Alpha Pro vs SMSL DO400
- D&A Alpha vs D&A Alpha Pro
- D&A Alpha Pro vs JDS Labs Element IV
- D&A Alpha Pro vs Benchmark DAC3 HGC
- D&A Alpha Pro vs Yulong DA10
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
D&A Alpha Pro: $699.00 Amazon eBay
Pros: Audio Science Review measured a SINAD of 121 dB, so its noise and distortion are inaudible. A rated 6,000 mW into 32 ohms and 700 mW into 300 ohms will drive nearly any headphone, including demanding planars, through 6.35 mm, 4.4 mm balanced or 4-pin XLR outputs. It doubles as a full desktop hub with USB, optical, coaxial, RCA and Bluetooth inputs (LDAC, aptX HD, AAC) plus RCA and XLR outputs.
Cons: It costs far more than the Topping DX1 II, which rates the same and measures the same 121 dB SINAD. The SMSL DO400 also matches its rating for less while measuring slightly cleaner. At 1,760 g and 225 mm wide, it needs real desk space.
Full D&A Alpha Pro review and specifications →
| Released | May 2025 (1 year ago) |
|---|---|
| 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 | 8.9” x 2.2” x 7.8” (225 x 55 x 199.3 mm) |
| Headphone Outputs | 6.35 mm, 4.4 mm balanced, 4-pin XLR balanced |
| Inputs | USB, optical, coaxial, Bluetooth, RCA |
| Output Power (300 ohms) | 700 mW (manufacturer rated) |
| Output Power (32 ohms) | 6,000 mW (manufacturer rated) |
| Outputs | RCA, XLR |
| SINAD | 121 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
| Weight | 3.9 lbs (1,760 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Gustard A20H: $752 HiFiGo eBay
Pros: A rated 2.4 W balanced into 32 ohms and 264 mW into 300 ohms is enough for planar magnetic and high impedance headphones alike. Inputs include USB, I2S over HDMI, AES/EBU, coaxial and optical, with RCA and XLR line outputs and a 60 step relay volume control. Audio Science Review measured 103 dB SINAD, clean enough for nearly all listening.
Cons: Its 103 dB SINAD trails many cheaper rivals, and the Tanchjim Luna rates higher with cleaner measurements for a small fraction of the price. There is no Bluetooth input, and at 6 kg it is a very large and heavy unit for what it delivers.
Full Gustard A20H review and specifications →
| Balanced Output | Yes (balanced headphone output, XLR line out) |
|---|---|
| DAC Chip | 2 x AK4497EQ |
| Device Type | DAC and headphone amp |
| Dimensions | 13” x 2.6” x 10.2” (330 x 65 x 260 mm) |
| Inputs | USB, I2S (HDMI), AES/EBU, coaxial, optical |
| Output Power (300 ohms) | 264 mW (manufacturer rated, balanced) |
| Output Power (32 ohms) | 2,400 mW (manufacturer rated, balanced) |
| Outputs | RCA, XLR |
| SINAD | 103 dB (measured by Audio Science Review) |
| Volume Control | Relay attenuator (60 steps) |
| Weight | 13.2 lbs (6 kg) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons