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 Little Labs Monotor ranks #14, rated 3.6/5, at $580, $169 cheaper, not enough of a saving to outweigh the sound-quality gap.
The Tom Christiansen Audio HPA-1 is the better-sounding option. 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 Little Labs Monotor: Audio Science Review measured a SINAD of 109 dB, clean for nearly all listening. The tradeoff: Little Labs doesn’t publish a power figure into 32 ohms, and there are no balanced headphone outputs.
Buy the Tom Christiansen Audio HPA-1. It is rated higher, and the $169 you would save on the Little Labs Monotor does not close the gap.
Want more options? Browse the full Headphone Amps and DACs rankings.
Specifications Side By Side
| Tom Christiansen Audio HPA-1 | Little Labs Monotor | |
|---|---|---|
| Price | $749.00 | $580.00 |
| Ranked | #10 of 19 in Headphone Amplifiers | #14 of 19 in Headphone Amplifiers |
| Device Type | Headphone amp | Headphone amp |
| SINAD | 119 dB (measured by Audio Science Review) | 109 dB (measured by Audio Science Review) |
| Output Power (32 ohms) | 1,200 mW (manufacturer rated) | - |
| Output Power (300 ohms) | 250 mW (manufacturer rated) | - |
| Headphone Outputs | 6.35 mm | 2 x 6.35 mm, 2 x 3.5 mm |
| Balanced Output | No | No |
| Inputs | RCA, XLR | XLR/TRS combo, TRS, 3.5 mm aux |
| Volume Control | Hardware knob (ALPS RK27 potentiometer) | Stepped attenuator knob |
| Dimensions | 5.5” x 2.2” x 8.3” (140 x 55 x 210 mm) | - |
| Weight | 1.9 lbs (850 g) | - |
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 Violectric HPA V550 PRO
- Tom Christiansen Audio HPA-1 vs Soncoz SGA1
- Tom Christiansen Audio HPA-1 vs SMSL VMV P2
- 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
Little Labs Monotor: $580.00 Sweetwater eBay
Pros: Audio Science Review measured a SINAD of 109 dB, clean for nearly all listening. It has two 6.35 mm and two 3.5 mm headphone outputs, XLR/TRS combo, TRS and 3.5 mm inputs, and a stepped attenuator for precise volume matching.
Cons: Little Labs doesn’t publish a power figure into 32 ohms, and there are no balanced headphone outputs. The JDS Labs Atom Amp 2 rates higher, measured cleaner and is rated at 2,650 mW into 32 ohms for far less.
Full Little Labs Monotor review and specifications →
| Balanced Output | No |
|---|---|
| Device Type | Headphone amp |
| Headphone Outputs | 2 x 6.35 mm, 2 x 3.5 mm |
| Inputs | XLR/TRS combo, TRS, 3.5 mm aux |
| SINAD | 109 dB (measured by Audio Science Review) |
| Volume Control | Stepped attenuator knob |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Little Labs Monotor vs Benchmark HPA4
- Little Labs Monotor vs Rupert Neve Designs RNHP
- Little Labs Monotor vs Chord Alto
- Little Labs Monotor vs Soncoz SGA1
- Little Labs Monotor vs Fosi Audio SK01
- Little Labs Monotor vs HeadAmp Gilmore Lite Mk2
- Little Labs Monotor vs Topping A90 Discrete
- Little Labs Monotor vs Topping A70 Pro