Pre Box RS2 Digital is the big brother of our award-winning and groundbreaking Pre Box S2 Digital preamp & DAC. Based on the same core design principles, the feature set is extended and driven to new heights. The result is a fantastic sounding and very versatile component – a perfect partner for cream-of-the-crop amplifiers and speakers alike.

Pre Box RS2 Digital is a line preamp & DAC using dual-mono configuration via dual ESS9038Q2M DAC chips by Sabre, providing high-end sound quality at a reasonable price. In addition to dual DACs, Pre Box RS2 Digital features separate signal paths for the left and right channels with support for up to 32bit/768kHz files in PCM and DSD formats (up to DSD512) via USB, covering any digital file you can buy or stream.

The analog output stage allows you to toggle between solid-state and tube so that you can choose based on preference. Eight digital filters are offered, one of them being the proprietary ‘optimal transients’ filter from the MQA creators. The unit comes MQA-ready, and these filters again allow you to tune the sound based on your preferences. Inside the unit, the USB input signal is processed by a powerful multi-core XMOS microcontroller with advanced Multi-Core RISC architecture. The CPLD MAX II (Complex Programmable Logic Device) Altera is used for re-clocking, which together with the XMOS microcontroller brings high-quality processing for both conventional and MQA digital information. For the ideal use of this technology, it is best to connect the Pre Box to our Stream Box S2 Ultra in conjunction with TIDAL.

You can also enjoy MQA quality by linking it with our new revolutionary CD transport, the CD Box RS2 T, which can be connected to the Pre Box RS2 Digital by I²S differential bus via the HDMI connector where the Pre Box RS2 Digital also provides the master clock (16.9344MHz). The headphone amplifier is the ultimate, no-compromise design. No coupling capacitors are used. The amplifier portion is DC coupled. A very fast DC servo assures no DC voltage in the output and said output is compatible with even demanding headphones.

A aluminum remote control is included in the package and the Pre Box RS2 Digital is available in a high-quality silver or black aluminum case. The sizeable front display screen shows all relevant information in a structured, easy-to-read way. Navigating the menu is a snap, allowing you to find your favorite settings with ease.

Additional information
Weight1.17 kg
Dimensions22.2 × 20.6 × 7.2 cm



  • Dual mono DACs: 2x ESS9038Q2M
  • High Quality optionally selectable upsampling of PCM and/or MQA content with proprietary filtering
  • Advanced re-clocking powered by new XMOS chip with Mulit-Core RISC architecture
  • 9 digital inputs: i²S HDMI, AES/EBU, Toslink, S/PDIF coax, Bluetooth v4.0
  • Analog: pre-out XLR/RCA/headphone, RCA input
  • Fully balanced dual mono design
  • Output stage switchable between 6922 tube & solid state
  • Ultra-linear and ultra low noise
  • New high-quality display with responsive and fast UI design
  • High quality full aluminium remote control included
  • Available in silver and black
  • Handmade in Europe


  • Frequency response: 20Hz – 20kHz (-0,3dB, -2,5dB)
  • Output voltage: 2,0V RMS – 0dBFS on digital inputs /RCA output, 4,0V RMS – 0dBFS on digital inputs /XLR output
  • Sampling rates: 32/44,1/48/88,2/96/176,4/192/352,8/384/705,6/768 kHz
  • DSD support: DSD64, DSD128, DSD256 and DSD512 (DoP, DSD512 native)
  • MQA support: full MQA unfolding by hardware for all digital inputs
  • Dynamic Range: 124dBA
  • Channel separation: > -117dB at [email protected]
  • SNR (20Hz – 20kHz): > 113dB at 0dB
  • THD: 0.005% solid state output/ 0.25% tube output
  • THD (20Hz – 20kHz): < 0.0003% @ 0 dB, 2V RMS, 1 kHz
  • THD+N (20Hz – 20kHz): < 0,0009%
  • Analog input sensitivity: 350mV
  • Line input impedance: 50kohms
  • USB data transfer : Asynchronous , DSD DoP up to DSD512 support and PCM up to 32b/768kHz
  • S/PDIF optical input: 2 x (24bit / 192kHz)
  • S/PDIF coaxial input: 1 x (24bit / 192kHz)
  • AES/EBU 1 x (24bit / 192kHz balanced)
  • I²S: for connection with CD Box RS2 T using supplied HDMI cable
  • Master clock output: 16.9344 MHz for CD Box RS2 T
  • Digital to Analogue converter: 2 x ESS9038Q2M 32-bit (dual mono)
  • Filter settings: 8x digital filter
  • Bluetooth version: Fully embedded Bluetooth® v4.0
  • Bluetooth music receiver codec: SBC, AAC, AptX
  • Output buffer: discrete and balanced, tube and solid state
  • Tubes: 4 x 6922EH
  • Headphone amplifier: discrete
  • Min. recommended impedance: 8 Ohm
  • Headphone output power: 90 mW / 300 Ohm; 245 mW / 33 Ohm; 150 mW / 8 Ohm
  • Display: 3,5” TFT module, 480×320, 360 cd/m2, contrast ratio 700, MVA technology
  • Balanced analog input: 1 x XLR
  • Unbalanced analog input: 1 x RCA
  • Variable balanced analog output: 1 x XLR
  • Variable unbalanced analog output: 1 x RCA
  • Headphone output: 1 x 6.3mm stereo JACK
  • Trigger sockets: 2 x 2,5mm 2-pole (1 x Trigger In, 1x Trigger Out)
  • Outboard power supply: 20V/3A DC, suitable for your country’s mains supply
  • Power consumption: max. 1A DC, <0,5W in standby


“The Pro-Ject CD Box RS2 Transport and Pre Box RS2 DAC punch way above their weight” – Steven Guttenberg, Audiophiliac

“Keeps up with the most advanced competitors” – Maxim Novik, TechWeek

“Throughout my listening, I was struck by how integrated, how completely together, music sounded through the Pre Box RS2 Digital” – Gordon Brockhouse, SoundStage

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