Pro-Ject Phono Box S3 B Phono Preamplifier

True Balanced Design · Fully Discrete Symmetrical Dual-Mono · Entry-Level High-End Balanced Phono Stage

The Pro-Ject Phono Box S3 B is an advanced model in the S series that supports True Balanced connections. It features fully discrete symmetrical dual-mono gain stages, a steel-aluminum composite chassis, and intuitive front panel adjustments, supporting both MM and MC cartridges. With its 5-pin mini XLR balanced input and XLR balanced output, it significantly reduces noise and enhances detail and dynamics.

Compact and sophisticated with complete functionality, it's a cost-effective choice for those looking to experience a balanced vinyl system.

Basic Product Information

• Type: Balanced MM / MC Phono Preamplifier
• Supported Cartridges: MM (Moving Magnet) and MC (Moving Coil)
• Inputs: 5-pin mini XLR Balanced + RCA Unbalanced
• Outputs: XLR Balanced + RCA Unbalanced
• Adjustment Method: Direct adjustment via front panel buttons
• Color: Black or Silver
• Origin: Handmade in Europe
• Accessories: External 18V DC Power Supply

Key Technology Highlights

• True Balanced Design: 5-pin mini XLR input + XLR output, fully leveraging the advantages of a balanced system
• Fully Discrete Symmetrical Dual-Mono Gain Stages: No integrated circuits used for cleaner sound and better dynamics
• Semi-Passive RIAA Equalization: Precisely reproduces the characteristics of records
• Direct Front Panel Adjustment: One-button setup for gain, impedance, and capacitance, intuitive operation
• Adjustable Gain: 40 / 45 / 60 / 65 dB (XLR output +6dB)
• Adjustable Input Impedance: 10 / 50 / 100 / 1k / 47kΩ
• Adjustable Capacitance: 50 / 150 / 300 / 400 pF
• Switchable Subsonic Filter: 20Hz / 18dB/octave
• Steel-Aluminum Composite Chassis: Effectively shields electromagnetic interference and vibrations
• Dual Input Memory: Can connect two turntables simultaneously and independently store settings

Detailed Specifications

• Input Impedance: 10 / 50 / 100 / 1k / 47kΩ
• Input Capacitance: 50 / 150 / 300 / 400 pF
• Gain: 40 / 45 / 60 / 65 dB (XLR +6dB)
• Signal-to-Noise Ratio: MM 103dBV / 110dBV (A-weighted); MC 85dBV / 90dBV (A-weighted)
• Total Harmonic Distortion: MM <0.001%, MC <0.005% at 1kHz; MM <0.008%, MC <0.01% at 20Hz–20kHz
• RIAA Accuracy: 20Hz–20kHz / max. 0.3dB
• Subsonic Filter: 20Hz / 18dB/octave
• Inputs: 1 × 5-pin mini XLR + 1 pair RCA
• Outputs: 1 pair XLR + 1 pair RCA
• Power: External 18V / 500mA DC
• Power Consumption: Approximately 170mA (Standby <0.5W)
• Dimensions: 206 × 55 × 153 mm (approx. 164mm including terminals)
• Weight: Approximately 930g

Sound Performance and Capabilities

The Phono Box S3 B delivers clean, transparent, and detailed sound. The background is extremely quiet, the soundstage is expansive, the midrange is natural and full-bodied, the bass is powerful and controlled, and the treble is clear without being harsh. With balanced connections, noise is significantly reduced, and details and dynamics are further enhanced, presenting music with a mature, precise, and convincing performance.

It is ideal for pairing with Pro-Ject turntables that support balanced output, fully unleashing the potential of MC cartridges.

Online Reviews

• SoundStage! Hi-Fi: Almost no competition at this price point, outstanding balanced design and adjustability, rated as a "Benchmark" product.
• FWD: Feature-rich, neutral and accurate sound, extremely high cost-effectiveness, rated 9.0.
• Users and Media: Convenient front panel adjustments, significant improvement with balanced connections, solid build quality, making it an ideal choice for an entry-level balanced system.