Improved Edition of a Modern Pro-Ject Classic

Since its release in 2017, our Pre Box S2 Digital quickly ascended to ‘exceptional’ status in the DAC market. It gained a reputation among digital audio enthusiasts for its remarkable ability to perform well beyond it’s price point.┬áThis achievement can be attributed to a combination of strengths in the design: a custom and proprietary clock design, meticulous PCB layout with discrete power supplies, dual-differential ESS DACs and an exclusive proprietary digital filter designed to deliver pristine and transparent transient response.

Given its enduring demand, the chip crisis of 2020-2021 hit Pre Box S2 Digital particularly hard. At that time, Pro-Ject reconvened with the original designer, John Westlake, to implement key improvements that further enhance the design, thus rejuvenating the product almost exactly 5 years after its original introduction.

Improved Internal Power Supply

The power supply units (PSUs) of the clock, DACs, and analog output stages have undergone enhancements to offer increased isolation from PC-USB power noise and achieve a wider/flatter output impedance across the entire audio bandwidth.

Redesigned Master Audio Clocks

We have redesigned and improved the discrete audio master clocks. This lowers the phase noise and further enhances the already-cutting-edge jitter performance.

New Output Stage with Higher Class A Current

The new analogue output stage, based around the SABRE9603Q, has higher Class A operating current, for improved performance with low impedance headphones and long cable runs.

New Headphone Amplifier

The entire design is now more energy efficient. A 12% reduction in PSU current while also offering higher Class A analog stage operating current resulting in lower distortion when used with low impedance headphones. On-the-go users with mobile devices or laptops will also appreciate the lower power draw, and will simultaneously benefit from more power for the energy being drawn. Anyone using low-impedance headphones or in-ears monitors, whether in a mobile, home, or work environment will experience a notable boost in sound quality too.

Unbeatable Value – Handmade in Europe

Normally up to 70% of hi-fi production cost goes toward the chassis or cabinet. By reducing the cabinet size and using the same enclosure for entire product lines, Pro-Ject can focus our resources on improving components & technology of a given hi-fi product. this The Pre Box S2 Digital Edition 2023 is carefully designed and handmade in Europe. We aim to develop a technically flawless device in a housing that is only as big as necessary to save raw materials. Due to the timeless design & rigid aluminium casework, the Pre Box S2 Digital Edition 2023 is built for eternity.

Additional information
Weight 0.366 kg
Dimensions 12.2 × 10.3 × 3.7 cm



  • Improved, more powerful output stage for headphones
  • Improved analog output stage (higher Class A current)
  • Redesigned discrete audio master clock
  • Improved internal power supply design
  • Less energy consumption, higher efficiency & more power
  • Less demanding on mobile battery life
  • Jitter levels below 100 femtoseconds
  • Dual-mono high-end Sabre ESS9038 DACs
  • Organic polymer capacitors and thin film miniMELF resistors
  • MQA hardware decoding
  • DSD64, DSD128, DSD256 & DSD512 (DoP, DSD512 native)
  • Up to 24bit/192kHz for optical & coax inputs
  • 8x selectable digital filter characteristics
  • 1x proprietary optimum transient digital filter
  • 1/4″ (6.3mm)headphone output
  • Synchronization of all internal oscillators
  • Gold-plated four layer PCB
  • Full aluminum/steel sandwich chassis in silver or black
  • Made in Europe


  • Digital inputs: USB (B), coaxial (RCA), optical (TOSLink)
  • D/A-converter: 2x ESS9038Q2M (32bit)
  • USB: up to DSD512 (DSD1024), PCM up to 32bit/768kHz
  • Optical: PCM up to 24bit/192kHz
  • Coaxial: PCM up to 24bit/192kHz
  • Filter settings: 7 options selectable on front
  • Frequency response: 20Hz-20kHz
  • Analog outputs: 1/4″ (6.3mm) headphone, variable RCA line out
  • Output voltage: 2.05V
  • Headphone impedance minumum: 8 ohms
  • Headphone output power: 6.6mW @ 600 ohms, 100mW @ 32 ohms
  • THD: 0.0003% @ 0dB, 2V RMS, 1kHz
  • Dynamic range: 124dBA
  • Outboard Power supply: 5V/1A DC (included)
  • Dimensions (WxHxD): 103 x 37 x 122mm (including knob and connectors)
  • Dimensions (standard): 4.06 x 1.46 x 4.80″
  • Mass (weight): 366g (0.81 lbs) without power supply


*This version of the driver for the Pre Box S2 Digital (‘Downloads’ section above) is specifically for computers that are running versions of Windows released BEFORE Windows 10. Attempting to install this driver on a computer running Windows 10 will potentially overwrite the existing correct driver and cause the Pre Box S2 Digital to behave in unexpected ways. Windows 10 already contains the correct driver for the Pre Box S2 Digital.