Pro-Ject Phono Box RS

Reference-Class Phono Preamplifier for Demanding Vinyl Listeners

The Pro-Ject Phono Box RS is a flagship phono preamplifier built for audiophiles who want detail, control, and transparency from every record. Designed around a true dual-mono architecture and ultra-low-noise circuitry, it lets you extract more musical information from your turntable without coloring the source or forcing you to compromise on connectivity.

Continuously Variable Impedance Loading

One of the RS’s defining advantages is continuously variable input impedance loading. Instead of fixed loading steps, you can fine-tune cartridge matching in real time and even hear the difference while music is playing. That makes it practical for optimizing new cartridges, comparing cables, or dialing in the exact tonal balance your system needs.

True Dual-Mono, Fully Balanced Design

The Phono Box RS uses a true dual-mono design, so left and right channels are processed independently for better channel separation, imaging, and overall stability. Its fully balanced circuitry supports both XLR and RCA inputs and outputs, which means it integrates cleanly into single-ended and balanced hi-fi chains alike.

Passive RIAA and DECCA Equalisation

Fully passive RIAA and DECCA equalisation helps preserve the neutrality of the original recording. Rather than imposing the character of active circuitry onto the signal path, the RS focuses on accurate playback, low distortion, and consistent tonal balance across the entire frequency range.

Audiophile-Grade Components

Pro-Ject uses high-performance parts throughout the RS. Input stages based on the Analog Devices SSM2019 and a Linear Technology LT1010 high-current buffer stage are part of the reason this unit delivers very low noise and distortion. Combined with its very low output impedance, the RS behaves well with a wide range of interconnects and cable lengths.

Build Quality and Shielding

A rigid metal casing protects the circuit from vibration, hum, and electromagnetic interference. In high-resolution vinyl systems where noise margins are thinner, that kind of shielding matters: it helps the phono stage sound cleaner, deeper, and more transparent from quiet passages to dynamic peaks.

Best For

• Reference and high-end turntable systems
• MM and MC cartridge setups requiring precise impedance tuning
• Balanced XLR signal chains and audiophile integrations
• Upgrading from entry-level phono stages to transparent, detailed playback

If you want a reference-class phono preamplifier that balances flagship refinement with practical usability, the Pro-Ject Phono Box RS is one of the strongest choices in its class.