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 Violectric HPA V550 PRO ranks #11, rated 4.6/5, and costs $3,599.99, which makes this an easy call rather than a real tradeoff.
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. The tradeoff: 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.
Why pick the Violectric HPA V550 PRO: Violectric rates it at 4,700 mW into 32 ohms and 1,450 mW into 300 ohms, enough to drive nearly any headphone, and Audio Science Review measured a SINAD of 111 dB, clean for nearly all listening. The tradeoff: The Topping A50 III rates higher and measured cleaner in Audio Science Review’s tests for a small fraction of the price.
Buy the Tom Christiansen Audio HPA-1. It is rated higher than the Violectric HPA V550 PRO 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
| Tom Christiansen Audio HPA-1 | Violectric HPA V550 PRO | |
|---|---|---|
| Price | $749.00 | $3,599.99 |
| Ranked | #10 of 19 in Headphone Amplifiers | #11 of 19 in Headphone Amplifiers |
| Device Type | Headphone amp | Headphone amp |
| SINAD | 119 dB (measured by Audio Science Review) | 111 dB (measured by Audio Science Review) |
| Output Power (32 ohms) | 1,200 mW (manufacturer rated) | 4,700 mW (manufacturer rated) |
| Output Power (300 ohms) | 250 mW (manufacturer rated) | 1,450 mW (manufacturer rated) |
| 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 | 2 x RCA, XLR |
| Volume Control | Hardware knob (ALPS RK27 potentiometer) | Hardware knob (256-step relay attenuator, remote) |
| Dimensions | 5.5” x 2.2” x 8.3” (140 x 55 x 210 mm) | 11.4” x 3.1” x 9.8” (290 x 80 x 248 mm) |
| Weight | 1.9 lbs (850 g) | - |
| Outputs | - | RCA, XLR |
Related Amp and DAC Comparisons
More top alternatives to 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
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.
As an eBay Partner, we may be compensated if you make a purchase.
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 Soncoz SGA1
- 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
Violectric HPA V550 PRO: $3,599.99 Amazon eBay
Pros: Violectric rates it at 4,700 mW into 32 ohms and 1,450 mW into 300 ohms, enough to drive nearly any headphone, and Audio Science Review measured a SINAD of 111 dB, clean for nearly all listening. It offers 6.35 mm, 4-pin XLR and 4.4 mm balanced headphone outputs, RCA and XLR inputs and outputs, and a 256-step relay volume control with a remote.
Cons: The Topping A50 III rates higher and measured cleaner in Audio Science Review’s tests for a small fraction of the price. It is an analog amp only, so you still need a separate DAC.
Full Violectric HPA V550 PRO review and specifications →
| Balanced Output | Yes (4-pin XLR, 4.4 mm, XLR line out) |
|---|---|
| Device Type | Headphone amp |
| Dimensions | 11.4” x 3.1” x 9.8” (290 x 80 x 248 mm) |
| Headphone Outputs | 6.35 mm, 4-pin XLR balanced, 4.4 mm balanced |
| Inputs | 2 x RCA, XLR |
| Output Power (300 ohms) | 1,450 mW (manufacturer rated) |
| Output Power (32 ohms) | 4,700 mW (manufacturer rated) |
| Outputs | RCA, XLR |
| SINAD | 111 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob (256-step relay attenuator, remote) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons