Short answer: the Tom Christiansen Audio HPA-1. It ranks #10 of 19 headphone amplifiers by measured performance, rated 4.7/5, at $749. The Soncoz SGA1 ranks #12, rated 4.5/5, at $649.99, $99.01 cheaper, which does not close the gap in measured performance.
Why pick the Tom Christiansen Audio HPA-1: Audio Science Review measured a SINAD of 119 dB, so its noise and distortion are inaudible and the amp is effectively transparent. Watch for: It costs several times more than the JDS Labs Atom Amp 2, which matches its rating with more than twice the rated power into 32 ohms.
What the Soncoz SGA1 does well: Audio Science Review measured 118 dB SINAD, so its noise and distortion are inaudible. The catch: It is an analog only amp with no digital inputs, so you need a separate DAC.
Buy the Tom Christiansen Audio HPA-1. It is rated higher, and saving $99.01 with the Soncoz SGA1 does not make up for the sound-quality gap.
Still deciding? The full Headphone Amps and DACs rankings cover every ranked option.
Specifications Side By Side
| Tom Christiansen Audio HPA-1 | Soncoz SGA1 | |
|---|---|---|
| Price | $749.00 | $649.99 |
| Ranked | #10 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) | 1,200 mW (manufacturer rated) | 420 mW (manufacturer rated at 33 ohms, balanced) |
| Output Power (300 ohms) | 250 mW (manufacturer rated) | 840 mW (manufacturer rated, balanced) |
| Headphone Outputs | 6.35 mm | 6.35 mm, 4-pin XLR balanced, 4.4 mm balanced |
| Balanced Output | No | Yes (4-pin XLR, 4.4 mm, XLR line out) |
| Inputs | RCA, XLR | RCA, XLR |
| Volume Control | Hardware knob (ALPS RK27 potentiometer) | Electronic stepped volume (MUSES72320) |
| Dimensions | 5.5” x 2.2” x 8.3” (140 x 55 x 210 mm) | 9.8” x 2.2” x 8.9” (250 x 55 x 225 mm) |
| Weight | 1.9 lbs (850 g) | 4.4 lbs (2,000 g) |
| Outputs | - | RCA, XLR |
Related Amp and DAC Comparisons
More worthwhile head-to-heads for Tom Christiansen Audio HPA-1:
- Topping A30 Pro vs Tom Christiansen Audio HPA-1
- Topping A70 Pro vs Tom Christiansen Audio HPA-1
- Topping A90 Discrete vs Tom Christiansen Audio HPA-1
- Schiit Midgard vs Tom Christiansen Audio HPA-1
- SMSL VMV P2 vs Tom Christiansen Audio HPA-1
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The Two Amps and DACs In Full
Tom Christiansen Audio HPA-1: $749.00 Tom Christiansen Audio eBay
Pros: Audio Science Review measured a SINAD of 119 dB, so its noise and distortion are inaudible and the amp is effectively transparent. A rated 1,200 mW into 32 ohms handles most planar magnetic headphones, with 250 mW into 300 ohms for high impedance dynamic models. It accepts both RCA and XLR inputs and uses a simple ALPS analog volume knob.
Cons: It costs several times more than the JDS Labs Atom Amp 2, which matches its rating with more than twice the rated power into 32 ohms. The only headphone output is a single 6.35 mm jack, so balanced headphone cables are not supported.
Full Tom Christiansen Audio HPA-1 review and specifications →
| Balanced Output | No |
|---|---|
| Device Type | Headphone amp |
| Dimensions | 5.5” x 2.2” x 8.3” (140 x 55 x 210 mm) |
| Headphone Outputs | 6.35 mm |
| Inputs | RCA, XLR |
| Output Power (300 ohms) | 250 mW (manufacturer rated) |
| Output Power (32 ohms) | 1,200 mW (manufacturer rated) |
| SINAD | 119 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob (ALPS RK27 potentiometer) |
| Weight | 1.9 lbs (850 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Tom Christiansen Audio HPA-1 vs Violectric HPA V550 PRO
- Tom Christiansen Audio HPA-1 vs SMSL VMV P2
- Tom Christiansen Audio HPA-1 vs Little Labs Monotor
- Tom Christiansen Audio HPA-1 vs Schiit Midgard
- Tom Christiansen Audio HPA-1 vs Rupert Neve Designs RNHP
- Tom Christiansen Audio HPA-1 vs Topping A90 Discrete
- Tom Christiansen Audio HPA-1 vs Topping A70 Pro
- Tom Christiansen Audio HPA-1 vs Topping A30 Pro
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