Posted on 23rd January, 2019


Pro-Ject may have built a foundation based on its high-performance turntables but with a complete range of Hi-Fi electronics, its latest release, the Stream Box S2 Ultra, proves that it's a cutting-edge company in the world of modern Hi-Fi.

The Stream Box S2 Ultra is “a versatile, audiophile-grade network bridge” that is built upon the revolutionary small-form-factor quad-core industrial version of the Raspberry Pi. 

It brings a simple method of adding high-resolution music streaming to any traditional hi-fi system via a USB connection to a DAC. It supports Spotify, TIDAL, Roon, AirPlay, DLNA and of course music stored on your local network.

The key feature for enthusiasts will be its Roon Ready certification, delivering a simple way to add another audio end-point to your multi-room ecosystem.

Inputs include 2 x USB-A, Micro USB-B, and both wired and wireless network. Outputs are limited to just USB-A for connection to a DAC, and a video-only HDMI.

The Stream Box S2 Ultra will handle just about any file type that your DAC is compatible with, including 352.8kHz PCM and DSD256. It will also pass-through MQA files for exact unfolding by an MQA capable DAC.

Designer John Westlake placed emphasis on three critical areas - provide bit-perfect Hi-Res with no data manipulation, support for DSD, and allow the DAC to be the master audio clock.

The result was to build upon the Raspberry Pi in conjunction with open-source software Volumio. Westlake's wave of the magic wand over the Raspberry Pi led to improvements relating to decreasing power supply noise and RF, as well as eliminating jitter. 

Westlake said:

This industrial version of the RPi3 called the CM3 module allows us to optimise the streamer hardware (PSU, RF and Clocking) while maintaining software compatibility with RPI. An important goal of our streamer solution is that we wanted an optimised “audio” streaming solution while not limiting the customer to a single software solution – for those skilled in software they can install any of the RPI based media players (Moode, LMS and even Kodi) etc.

Westlake expanded upon why he elected to use the Raspberry Pi, along with delving into more details on the improvements that have been made in a post you can read here.

The Pro-Ject Stream Box S2 Ultra has been extensively developed and refined to bring a simple, yet high-quality way of adding high-resolution streaming to your Hi-Fi system. 

Available now, the Pro-Ject Stream Box S2 Ultra sells for $1,199 RRP and is available in black or silver.

For more information and to find your nearest dealer visit Pro-Ject.


Marc Rushton's avatar

Marc Rushton

StereoNET’s Founder & Publisher and still buried deep in the review room auditioning everything from docks to soundbars, amplifiers and headphones. Marc is also the founder of the annual International HiFi Show.

Get the latest.

Sign up to discover the best news and review from StereoNET in our FREE Newsletter.

Posted in: Hi-Fi
Tags: pro-ject  interdyn