Short answer: the Essence HDACC II-4K. It ranks #37 of 43 DAC and headphone amp combos by measured performance, rated 3.2/5, at $649. The Pro-Ject Pre Box S2 Digital ranks #38, rated 2.9/5, at $399, $250 cheaper, a saving that is not big enough to make up the sound-quality gap.
The Essence HDACC II-4K is the better-sounding choice. It accepts four HDMI inputs with pass-through plus USB, optical, coaxial and analog, making it a hub for TV and console audio. The catch: Audio Science Review measured 99 dB SINAD, fine for most headphones but sensitive in-ear monitors may reveal hiss.
Why pick the Pro-Ject Pre Box S2 Digital: It accepts USB, optical and coaxial inputs and also works as a preamp with a variable RCA output, all in a compact box about the size of a paperback. The catch: Pro-Ject rates it at only 68 mW into 32 ohms, which suits in-ear monitors and easy headphones but not demanding full-size models.
Buy the Essence HDACC II-4K. It is rated higher, and the $250 you would save on the Pro-Ject Pre Box S2 Digital does not close the gap.
Want more options? Browse the full Headphone Amps and DACs rankings.
Specifications Side By Side
| Essence HDACC II-4K | Pro-Ject Pre Box S2 Digital | |
|---|---|---|
| Price | $649.00 | $399.00 |
| Ranked | #37 of 43 in DAC and Headphone Amp Combos | #38 of 43 in DAC and Headphone Amp Combos |
| Device Type | DAC and headphone amp | DAC and headphone amp |
| SINAD | 99 dB (measured by Audio Science Review) | 100 dB (measured by Audio Science Review) |
| Headphone Outputs | 6.35 mm | 6.35 mm |
| Balanced Output | Yes (XLR line out) | No |
| Inputs | 4 x HDMI, USB-B, optical, coaxial, 3.5 mm analog | USB-B, optical, coaxial |
| Outputs | RCA, XLR, optical, coaxial, HDMI pass-through | RCA (variable) |
| DAC Chip | ES9028PRO | 2 x ES9038Q2M |
| Volume Control | Hardware knob, remote | Hardware knob |
| Dimensions | 8.8” x 1.9” x 5.7” (223 x 48 x 145 mm) | 4.1” x 1.5” x 4.8” (103 x 37 x 122 mm) |
| Weight | 2 lbs (886 g) | 0.8 lbs (366 g) |
| Output Power (32 ohms) | - | 68 mW (manufacturer rated) |
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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
Essence HDACC II-4K: $649.00 Essence Electrostatic eBay
Pros: It accepts four HDMI inputs with pass-through plus USB, optical, coaxial and analog, making it a hub for TV and console audio. RCA and balanced XLR outputs, digital outputs and a remote controlled volume knob add flexibility.
Cons: Audio Science Review measured 99 dB SINAD, fine for most headphones but sensitive in-ear monitors may reveal hiss. Essence doesn’t publish a 32 ohm power figure, there is only a 6.35 mm headphone jack, and the Neutron HiFi DAC V1 rates higher for much less.
Full Essence HDACC II-4K review and specifications →
| Balanced Output | Yes (XLR line out) |
|---|---|
| DAC Chip | ES9028PRO |
| Device Type | DAC and headphone amp |
| Dimensions | 8.8” x 1.9” x 5.7” (223 x 48 x 145 mm) |
| Headphone Outputs | 6.35 mm |
| Inputs | 4 x HDMI, USB-B, optical, coaxial, 3.5 mm analog |
| Outputs | RCA, XLR, optical, coaxial, HDMI pass-through |
| SINAD | 99 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob, remote |
| Weight | 2 lbs (886 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Pro-Ject Pre Box S2 Digital: $399.00 Amazon eBay
Pros: It accepts USB, optical and coaxial inputs and also works as a preamp with a variable RCA output, all in a compact box about the size of a paperback. Audio Science Review measured a SINAD of 100 dB, which is fine for most headphones.
Cons: Pro-Ject rates it at only 68 mW into 32 ohms, which suits in-ear monitors and easy headphones but not demanding full-size models. At 100 dB SINAD, sensitive in-ears may reveal some hiss, it has no balanced outputs, and the Neutron HiFi DAC V1 rates higher and measured cleaner for less.
Full Pro-Ject Pre Box S2 Digital review and specifications →
| Released | 2017 (9 years ago) |
|---|---|
| Balanced Output | No |
| DAC Chip | 2 x ES9038Q2M |
| Device Type | DAC and headphone amp |
| Dimensions | 4.1” x 1.5” x 4.8” (103 x 37 x 122 mm) |
| Headphone Outputs | 6.35 mm |
| Inputs | USB-B, optical, coaxial |
| Output Power (32 ohms) | 68 mW (manufacturer rated) |
| Outputs | RCA (variable) |
| SINAD | 100 dB (measured by Audio Science Review) |
| Volume Control | Hardware knob |
| Weight | 0.8 lbs (366 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons