Short answer: the Topping A90 Discrete. It ranks #4 of 19 headphone amplifiers by measured performance, rated 4.8/5, at $599; the Soncoz SGA1 ranks #12, rated 4.5/5, and costs $649.99, so there is not much of a tradeoff to weigh.
The case for the Topping A90 Discrete: Audio Science Review measured a SINAD of 119 dB, so its noise and distortion are inaudible. The catch: It is a headphone amp only, so it needs a separate DAC.
The case for the Soncoz SGA1: Audio Science Review measured 118 dB SINAD, so its noise and distortion are inaudible. Watch for: It is an analog only amp with no digital inputs, so you need a separate DAC.
Buy the Topping A90 Discrete. It is rated higher than the Soncoz SGA1 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Looking for alternatives? See the complete Headphone Amps and DACs rankings.
Specifications Side By Side
| Topping A90 Discrete | Soncoz SGA1 | |
|---|---|---|
| Price | $599.00 | $649.99 |
| Ranked | #4 of 19 in Headphone Amplifiers | #12 of 19 in Headphone Amplifiers |
| Device Type | Headphone amp | Headphone amp |
| SINAD | 119 dB (measured by Audio Science Review) | 118 dB (measured by Audio Science Review) |
| Output Power (32 ohms) | 6,700 mW (manufacturer rated, balanced) | 420 mW (manufacturer rated at 33 ohms, balanced) |
| Output Power (300 ohms) | 1,000 mW (manufacturer rated, balanced) | 840 mW (manufacturer rated, balanced) |
| Headphone Outputs | 6.35 mm, 4.4 mm balanced, 4-pin XLR balanced | 6.35 mm, 4-pin XLR balanced, 4.4 mm balanced |
| Balanced Output | Yes (4.4 mm, 4-pin XLR) | Yes (4-pin XLR, 4.4 mm, XLR line out) |
| Inputs | RCA, XLR | RCA, XLR |
| Outputs | RCA, XLR (preamp) | RCA, XLR |
| Volume Control | Hardware knob (relay R2R) and remote | Electronic stepped volume (MUSES72320) |
| Dimensions | 8.7” x 1.8” x 6.3” (222 x 45 x 160 mm) | 9.8” x 2.2” x 8.9” (250 x 55 x 225 mm) |
| Weight | - | 4.4 lbs (2,000 g) |
Related Amp and DAC Comparisons
More worthwhile head-to-heads for Topping A90 Discrete:
- Topping A30 Pro vs Topping A90 Discrete
- Topping A70 Pro vs Topping A90 Discrete
- Schiit Midgard vs Topping A90 Discrete
- SMSL VMV P2 vs Topping A90 Discrete
- Topping A90 Discrete vs Tom Christiansen Audio HPA-1
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 A90 Discrete: $599.00 Amazon eBay
Pros: Audio Science Review measured a SINAD of 119 dB, so its noise and distortion are inaudible. A rated 6,700 mW into 32 ohms and 1,000 mW into 300 ohms from the balanced outputs is enough for nearly any headphone. It offers 6.35 mm, 4.4 mm and 4-pin XLR outputs, a relay volume control with remote, and RCA and XLR preamp outputs for powered speakers.
Cons: It is a headphone amp only, so it needs a separate DAC. The Topping A50 III rates the same and measures slightly cleaner at 121 dB for far less. The Topping A70 Pro rates the same with more rated power for less.
Full Topping A90 Discrete review and specifications →
| Balanced Output | Yes (4.4 mm, 4-pin XLR) |
|---|---|
| Device Type | Headphone amp |
| Dimensions | 8.7” x 1.8” x 6.3” (222 x 45 x 160 mm) |
| Headphone Outputs | 6.35 mm, 4.4 mm balanced, 4-pin XLR balanced |
| Inputs | RCA, XLR |
| Output Power (300 ohms) | 1,000 mW (manufacturer rated, balanced) |
| Output Power (32 ohms) | 6,700 mW (manufacturer rated, balanced) |
| Outputs | RCA, XLR (preamp) |
| SINAD | 119 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob (relay R2R) and remote |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Topping A90 Discrete vs Schiit Midgard
- Topping A90 Discrete vs Topping A70 Pro
- Topping A90 Discrete vs SMSL VMV P2
- Topping A90 Discrete vs Topping A30 Pro
- Topping A90 Discrete vs Tom Christiansen Audio HPA-1
- Topping A90 Discrete vs Violectric HPA V550 PRO
- Topping A90 Discrete vs Little Labs Monotor
- Topping A90 Discrete vs Rupert Neve Designs RNHP
- See all 9 comparisons
Soncoz SGA1: $649.99 HiFiGo eBay
Pros: Audio Science Review measured 118 dB SINAD, so its noise and distortion are inaudible. It offers 6.35 mm, 4-pin XLR and 4.4 mm balanced headphone outputs, RCA and XLR inputs and outputs, and a stepped electronic volume control, with 840 mW into 300 ohms for high impedance headphones.
Cons: It is an analog only amp with no digital inputs, so you need a separate DAC. Soncoz rates it at 420 mW balanced into 33 ohms rather than 32, which drives most headphones but is modest next to the Topping L30, a higher rated amp that costs far less.
Full Soncoz SGA1 review and specifications →
| Balanced Output | Yes (4-pin XLR, 4.4 mm, XLR line out) |
|---|---|
| Device Type | Headphone amp |
| Dimensions | 9.8” x 2.2” x 8.9” (250 x 55 x 225 mm) |
| Headphone Outputs | 6.35 mm, 4-pin XLR balanced, 4.4 mm balanced |
| Inputs | RCA, XLR |
| Output Power (300 ohms) | 840 mW (manufacturer rated, balanced) |
| Output Power (32 ohms) | 420 mW (manufacturer rated at 33 ohms, balanced) |
| Outputs | RCA, XLR |
| SINAD | 118 dB (measured by Audio Science Review) |
| Volume Control | Electronic stepped volume (MUSES72320) |
| Weight | 4.4 lbs (2,000 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Soncoz SGA1 vs Benchmark HPA4
- Soncoz SGA1 vs Violectric HPA V550 PRO
- Soncoz SGA1 vs Little Labs Monotor
- Soncoz SGA1 vs Tom Christiansen Audio HPA-1
- Soncoz SGA1 vs Rupert Neve Designs RNHP
- Soncoz SGA1 vs SMSL VMV P2
- Soncoz SGA1 vs HeadAmp Gilmore Lite Mk2
- Soncoz SGA1 vs Topping A70 Pro
- See all 9 comparisons