Pro-Ject Head Box S3 B & Head Box DS3 B

Pro-Ject emphasises that balanced headphone amplifiers are often only balanced at the socket level rather than throughout the signal path. With both new models, the company has instead implemented a genuinely fully balanced topology from input to output. Whether using RCA or XLR inputs, the entire signal chain remains balanced, ensuring maximum channel separation and minimal noise. Headphones can be connected through a wide choice of outputs: 4.4 mm Pentaconn and four-pin XLR for balanced listening, plus 3.5 mm and 6.3 mm sockets for single-ended headphones. An RCA bypass loop output simplifies system expansion and makes it easy to pair the units with other amplifiers or integrate them into existing setups without reconfiguration.

The Head Box S3 B stands as the entry point to the balanced range, but its engineering is far from basic. Its fully balanced signal chain is complemented by a power stage built around two TPA6120A2 amplifier chips chosen for their stability and low-noise characteristics. The result is up to 820 mW of fully balanced output into 32 ohms, supported by 480 mW into 8 ohms, 680 mW into 16 ohms and 320 mW into 300 ohms. Noise performance exceeds 115 dB (A-weighted), distortion stays below 0.002 percent at 1 kHz and crosstalk is rated better than -81 dB at 10 kHz. Pro-Ject positions the S3 B as a model tuned to deliver exactly the level of power that matters for real listening, avoiding inflated wattage figures in favour of clean, refined and controlled amplification suited to 98 percent of headphones on the market.

For listeners who need more headroom - or own rare, current-hungry headphones - the Head Box DS3 B doubles the available power and adopts a fully discrete amplifier topology. It delivers up to 1,500 mW into 32 ohms in balanced mode, alongside 510 mW into 8 ohms, 900 mW into 16 ohms and 560 mW into 300 ohms. Its 118 dB (A-weighted) signal-to-noise ratio and distortion figures below 0.002 percent reflect Pro-Ject's focus on extracting the maximum detail and dynamic nuance from any recording. The DS3 B is designed to provide effortless drive, greater warmth and improved spatial authority, making it a strong match for high-end planar magnetics and other low-sensitivity headphones. The gain structure is optimised for both RCA and XLR inputs and the frequency response remains tightly controlled, with less than -0.2 dB deviation across the audible band.

Across both models, Pro-Ject underscores an important point - headline power figures alone do not guarantee better performance. The company notes that some competing products claim more than 2 W into 30 ohms, but "the correct combination gives the best sound" - a principle borrowed from loudspeaker amplification. In practice, this means focusing on noise performance, balanced topology, properly matched power stages and a circuit layout that avoids unnecessary complications. This approach, combined with carefully selected components, is designed to preserve the purity of the analogue path and maintain control even at high levels.

Both units share the same design language as the rest of the S3 and DS3 series. Full aluminium chassis construction provides mechanical rigidity and high electromagnetic shielding, while the control elements and buttons are machined from aluminium for a solid, precise tactile response. The compact footprint allows easy placement on a desk or small system rack without compromising connectivity. Each model is available in silver or black, made entirely in Europe and assembled under Pro-Ject's long-standing manufacturing philosophy aimed at maximising performance per euro. The Head Box S3 B and Head Box DS3 B will be available from Pro-Ject dealers from January 2026. Recommended prices are set at €399 for the S3 B and €699 for the DS3 B. Info and pictures by Pro-Ject Audio Systems.