Short answer: the Benchmark HPA4. It ranks #13 of 19 headphone amplifiers by measured performance, rated 4.0/5, at $3,499; the Chord Alto ranks #16, rated 3.2/5, and costs $4,320, so there is not much of a tradeoff to weigh.
The Benchmark HPA4 is the better-sounding pick. Audio Science Review measured a SINAD of 119 dB, so the amp is transparent. The tradeoff: Benchmark does not publish a power figure into 32 ohms, so its output into low impedance planar magnetic headphones is unconfirmed.
Why pick the Chord Alto: Chord rates it at 2,100 mW into 32 ohms and 281 mW into 300 ohms, enough for most planar magnetic headphones and high impedance models alike. The tradeoff: Audio Science Review measured a SINAD of only 85 dB, a real audible weakness, especially with sensitive headphones.
Buy the Benchmark HPA4. It is rated higher than the Chord Alto and costs less, so only choose the other one for a particular feature it does better.
Still deciding? The full Headphone Amps and DACs rankings cover every ranked option.
Specifications Side By Side
| Benchmark HPA4 | Chord Alto | |
|---|---|---|
| Price | $3,499.00 | $4,320.00 |
| Ranked | #13 of 19 in Headphone Amplifiers | #16 of 19 in Headphone Amplifiers |
| Device Type | Headphone amp | Headphone amp |
| SINAD | 119 dB (measured by Audio Science Review) | 85 dB (measured by Audio Science Review) |
| Output Power (300 ohms) | 441 mW (calculated from manufacturer rated 11.5 Vrms into 300 ohms) | 281 mW (manufacturer rated) |
| Headphone Outputs | 6.35 mm, 4-pin XLR balanced | 6.35 mm, 4.4 mm balanced, 4-pin XLR balanced |
| Balanced Output | Yes (4-pin XLR headphone, XLR line out) | Yes (4.4 mm, 4-pin XLR, XLR line out) |
| Inputs | 2 x XLR, 2 x RCA | RCA, XLR, 4.4 mm balanced |
| Outputs | XLR, RCA | RCA, XLR |
| Volume Control | Hardware knob (256-step relay attenuator, IR remote) | Hardware knob |
| Dimensions | 8.7” x 3.9” x 8.3” (220 x 99 x 212 mm) | 7.9” x 1.8” x 8.5” (200 x 44.5 x 215 mm) |
| Weight | 7.9 lbs (3,600 g) | 4.9 lbs (2.2 kg) |
| Output Power (32 ohms) | - | 2,100 mW (manufacturer rated) |
Related Amp and DAC Comparisons
More worthwhile head-to-heads for Benchmark HPA4:
- Violectric HPA V550 PRO vs Benchmark HPA4
- Soncoz SGA1 vs Benchmark HPA4
- Benchmark HPA4 vs Little Labs Monotor
- Violectric HPA V550 PRO vs Chord Alto
- Chord Alto vs Rupert Neve Designs RNHP
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
Benchmark HPA4: $3,499.00 Benchmark Media Systems eBay
Pros: Audio Science Review measured a SINAD of 119 dB, so the amp is transparent. It has a 4-pin XLR balanced headphone output, XLR and RCA line outputs for use as a preamp, and a 256 step relay volume control with IR remote. It is rated for 441 mW into 300 ohms, ample for high impedance headphones.
Cons: Benchmark does not publish a power figure into 32 ohms, so its output into low impedance planar magnetic headphones is unconfirmed. It costs far more than the JDS Labs Atom Amp 2, which rates higher with similar measured cleanliness. It has no built in DAC.
Full Benchmark HPA4 review and specifications →
| Balanced Output | Yes (4-pin XLR headphone, XLR line out) |
|---|---|
| Device Type | Headphone amp |
| Dimensions | 8.7” x 3.9” x 8.3” (220 x 99 x 212 mm) |
| Headphone Outputs | 6.35 mm, 4-pin XLR balanced |
| Inputs | 2 x XLR, 2 x RCA |
| Output Power (300 ohms) | 441 mW (calculated from manufacturer rated 11.5 Vrms into 300 ohms) |
| Outputs | XLR, RCA |
| SINAD | 119 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob (256-step relay attenuator, IR remote) |
| Weight | 7.9 lbs (3,600 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Chord Alto: $4,320.00 Headphones.com eBay
Pros: Chord rates it at 2,100 mW into 32 ohms and 281 mW into 300 ohms, enough for most planar magnetic headphones and high impedance models alike. It has 6.35 mm, 4.4 mm balanced and 4-pin XLR balanced headphone outputs, plus RCA, XLR and 4.4 mm inputs and RCA and XLR outputs for use as a preamp.
Cons: Audio Science Review measured a SINAD of only 85 dB, a real audible weakness, especially with sensitive headphones. It costs far more than the Sennheiser HDV 820, which rates higher and measured much cleaner, and its inputs are all analog, so you need a separate DAC for digital sources.
Full Chord Alto review and specifications →
| Released | 2025 (1 year ago) |
|---|---|
| Balanced Output | Yes (4.4 mm, 4-pin XLR, XLR line out) |
| Device Type | Headphone amp |
| Dimensions | 7.9” x 1.8” x 8.5” (200 x 44.5 x 215 mm) |
| Headphone Outputs | 6.35 mm, 4.4 mm balanced, 4-pin XLR balanced |
| Inputs | RCA, XLR, 4.4 mm balanced |
| Output Power (300 ohms) | 281 mW (manufacturer rated) |
| Output Power (32 ohms) | 2,100 mW (manufacturer rated) |
| Outputs | RCA, XLR |
| SINAD | 85 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
| Weight | 4.9 lbs (2.2 kg) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons