Pro-Ject CD Box RS2 Transport silver

The CD Box RS2 Transport from Pro-Ject is a CD transport developed in partnership with StreamUnlimited. It uses the CD-Pro 8 mechanism paired with the Blue Tiger CD-84 servo. This technical choice, rare on the market, is also found in devices offered by other manufacturers in higher price ranges.

An exceptional mechanism in an anti-vibration enclosure

The CD Box RS2 T is based on a mechanical design that makes no compromises with parasitic vibrations. Its CD-Pro 8 mechanism integrates the servo directly into its aluminum body, with the entire assembly suspended on a sophisticated anti-vibration system combining carbon plates, carbon fiber tubes, springs, and silicone dampers. This multi-stage suspension precisely controls the vibrational spectrum reaching the reading mechanism, creating total mechanical isolation between the external environment and the data reading process.

The main chassis, machined from a solid block of aluminum, ensures structural rigidity that never deforms, even under high heat. The gear wheels of the sled glide on precision steel shafts, while the turntable is machined from steel and then chromed—a construction designed to endure for decades without mechanical degradation. The magnetic clamp, made from a newly developed, perfectly balanced aluminum alloy, holds the disc with constant pressure to ensure uniform rotation and flawless playback.

This obsession with vibration control extends to the top lid, which folds down fully on its rear hinges. Once closed, it creates an environment impervious to airborne vibrations, completing the isolation of the mechanism. The front LCD displays essential information—time, tracks, CD-Text when available—with two switchable display modes (white on black or black on white) and adjustable brightness.

The Viennese legacy of digital CD

The genesis of this transport is worth exploring. Vienna historically hosted the Philips development department for CD players, and the engineers who contributed to that seminal invention formed StreamUnlimited. Michael Jirousek, a leading figure in CD development, personally oversaw the creation of the CD Box RS2 T. This direct technical lineage to the pioneers of the format explains the sophistication of the CD-Pro 8 mechanism, which represents the culmination of decades of expertise in precision optical reading.

Pro-Ject is the first manufacturer to use this CD-Pro 8 and Blue Tiger CD-84 combination. The Blue Tiger servo orchestrates playback with a precision that extracts a data stream perfectly faithful to the recorded signal, without interpolation or rough correction. This purist approach sets the RS2 T apart from conventional players that compensate for mechanical shortcomings with digital tricks that degrade sound quality.

Four digital outputs for every DAC

The deliberate absence of an internal converter follows a precise logic: to allow enthusiasts already equipped with a reference DAC to fully leverage their investment. The rear panel offers four types of digital connections, each addressing specific needs.

The coaxial S/PDIF on RCA and the optical Toslink output are standard connections, compatible with the vast majority of converters. The AES/EBU output on balanced XLR represents a higher qualitative step, with balanced transmission that minimizes electromagnetic interference over long runs.

But it’s the I²S output with Master Clock via HDMI that is the ultimate connection. This protocol physically separates data and clock signals, eliminating the jitter inherent in other digital formats. This link, optimized for Pro-Ject’s Pre Box RS2 Digital (master frequency of 16.9344 MHz), bypasses the structural limitations of S/PDIF and enables absolutely bit-perfect transmission. Note, however: this I²S implementation remains proprietary to Pro-Ject and does not guarantee compatibility with DACs from other brands using this protocol.

The external power supply (20V/3A) keeps the power circuits away from sensitive electronics. Power consumption remains modest—600 mA in operation, less than 0.5 W in standby—attesting to an energy-efficient design.

Frequently Asked Questions

Can the CD Box RS2 T play SACDs or burned CDs? No, this transport is designed exclusively for playback of standard Red Book Audio CDs (CD-DA). It does not support SACD, DVD-Audio formats, or CD-R/RW with MP3 or other compressed files. This specialization ensures total optimization for conventional CD playback.

What’s the difference between the I²S/HDMI output and the other digital outputs? The I²S output physically separates data and clock signals, theoretically eliminating jitter (timing noise) that affects S/PDIF transmissions. However, this implementation remains proprietary to Pro-Ject and is guaranteed compatible only with their own RS2 DACs. For other converters, prioritize AES/EBU, which already provides higher-quality balanced transmission than standard S/PDIF.

Is the included external power supply sufficient, or should I invest in a linear power supply? The supplied switching power supply already enables remarkable performance, as evidenced by awards obtained with the stock configuration. A high-quality external linear power supply (Pro-Ject Power Box RS Uni or third-party alternatives compatible with 20V/3A) can nevertheless bring noticeable improvements in background noise and spatial dimensionality.

How does the CD-Pro 8 mechanism compare with others on the market? StreamUnlimited’s CD-Pro 8 represents the current state of the art in CD mechanisms. Only Gryphon (Ethos at €32,500) and certain German models around €8,000 employ this technology. More common mechanisms (often adapted computer drives) rely more heavily on error correction and interpolation, potentially degrading the original signal.

Does top-loading offer real advantages over front-loading? Top-loading eliminates the motorized drawer, a source of vibrations and mechanical complexity. The magnetic clamp ensures optimal coupling between the disc and the mechanism, reducing vibrations induced by rotation. This configuration also allows direct access for disc changes, without intermediate mechanisms that can develop play over time.

Can the CD Box RS2 T be used with any DAC on the market? Yes, via the S/PDIF (coaxial or optical) and AES/EBU outputs, the transport is compatible with all DACs equipped with these standard inputs. The I²S over HDMI output remains specific to the Pro-Ject ecosystem. Just ensure your DAC accepts the 16-bit/44.1 kHz signal of the Red Book CD format.

Technical Specifications

Mechanism and construction

• Top-loading mechanism with magnetic disc clamp
• CD-Pro 8 transport with CD-84 servo (StreamUnlimited, Vienna)
• Anti-vibration suspension: carbon, springs, and silicone
• Fully machined from solid aluminum
• Rigid chassis machined from a solid block of aluminum
• Balanced aluminum-alloy disc clamp for stable playback
• Robust, anti-distortion, and anti-vibration design
• Durability: resistant to thermal deformation, precision steel shafts

Formats and compatibility

• Supported formats: Red Book CD-DA only
• No internal digital-to-analog converter
• Requires an external converter (ideal for audiophiles with a high-end DAC)

Digital outputs

• AES/EBU (balanced XLR)
• S/PDIF optical (Toslink)
• S/PDIF coaxial (RCA)
• I²S with master clock via HDMI
  • High-end connection
  • Perfect bit transmission without jitter
  • Perfect with the Pre Box RS2 Digital

Power and consumption

• External power supply: 20 V / 3000 mA DC
• Power consumption: 600 mA DC
• Standby consumption: < 0.5 W

Dimensions and weight

• Dimensions (W × H × D): 206 × 78 × 200 mm (210 mm with connectors)
• Weight: 3.0 kg (without power supply)

Box contents

• CD Box RS2 T
• Aluminum infrared remote control
• 1 CR2032 (or CR2025) battery
• External power supply
• User manual

General information

• LCD display showing: time, tracks, text (CD-Text)
• Available in silver or black
• Ultra-precise CD transport with high-tech servo control
• Exceptional mechanical and vibration isolation (carbon and solid aluminum)
• I²S output with master clock for perfect integration with high-end DACs
• European manufacturing (designed with StreamUnlimited, former Philips CD developers)
• Elegant and robust design