Pro-Ject Tube Box S2 silver

The Pro-Ject Tube Box S2 is a phono preamplifier designed for vinyl enthusiasts. As the successor to the Tube Box S, this model stands out with its meticulous design and high-quality components, aimed at optimizing the vinyl listening experience.

The Magic of Tubes for a Unique Sound Signature

At the heart of the Tube Box S2 are two ECC83 (12AX7) tubes, one per channel. These tubes deliver the warmth and richness characteristic of tube amplification while maintaining precision and dynamics. A major advantage of the Tube Box S2 is the ability to replace these tubes, allowing users to experiment with different models to customize the sound signature to their preferences.

The input stage uses carefully selected FET transistors for their ultra-low noise and distortion-free performance, ensuring a clean initial amplification of the phono cartridge signal. The RIAA equalization is implemented in two stages, with both active and passive circuits, for optimal accuracy.

Versatility and Precise Adjustments

The Tube Box S2 excels in versatility, being compatible with both moving magnet (MM) and moving coil (MC) cartridges. To perfectly adapt to any setup, Pro-Ject has included numerous adjustment options accessible from the front or rear of the device.

The gain is adjustable on the front panel with six levels available (40, 43, 50, 53, 60, 63 dB), allowing you to optimize the output level based on the cartridge used and the rest of your hi-fi system. The input impedance can be set to five values for MC cartridges (10, 100, 470, 1k, 2k ohms), while it is fixed at 47k ohms for MM cartridges.

The input capacitance is also adjustable with six settings (50, 150, 270, 370, 490, 590 pF), enabling fine-tuning of the cartridge’s frequency response. A switchable subsonic filter (20 Hz, 12 dB/octave) completes these options, eliminating unwanted infrasonic disturbances.

An Immersive Listening Experience

The Tube Box S2 delivers exceptional sound reproduction, characterized by great transparency and a precise soundstage. The bass is deep and controlled, the midrange rich and warm, and the treble remarkably pure. Dynamics are preserved, faithfully reproducing even the subtlest nuances of vinyl recordings.

On complex compositions, the Tube Box S2 demonstrates authority while maintaining finesse and nuance. The absence of harshness in the high frequencies ensures a comfortable listening experience, even during extended sessions. The characteristic warmth of tubes adds an organic and engaging dimension to the music without compromising precision.

A Significant Evolution

Compared to its predecessor, the Tube Box S, the S2 brings several notable improvements. The fully discrete design and use of higher-quality components contribute to increased transparency and a more precise soundstage. The expanded adjustment options, particularly for gain, allow for better compatibility with a wide range of phono cartridges.

The reinforced chassis and attention to vibration isolation also enhance overall performance by reducing interference and unwanted noise. These advancements make the Tube Box S2 a phono preamplifier capable of competing with much more expensive models.

Technical Specifications

Main Features

• Compatible with moving magnet (MM) and moving coil (MC) cartridges
• Precise two-stage RIAA equalization, passive/active
• Fully discrete circuit design without operational amplifiers
• Ultra-low noise circuit with field-effect transistor (FET) input stage
• Dual mono circuit for optimal channel separation
• Front-panel subsonic filter
• Front-panel gain adjustment

Tubes and Components

• 2 ECC83 tubes (replaceable)
• Configuration: 2 × ECC83 (12AX7)
• Polystyrene capacitors used where possible
• Gold-plated RCA inputs and outputs

Power Supply and Construction

• External power supply and multiple internal power supplies
• High-voltage anode power supply with careful filtering
• Aluminum/metal sandwich casing protecting against vibrations and electromagnetic interference
• Available finishes: silver, black

Technical Specifications

• Input impedance: 10, 100, 470, 1 k, 2 k Ω, fixed 47 k Ω
• Capacitance: 50, 150, 270, 370, 490, 590 pF
• MM/MC gain: 40, 43, 50, 60, 63 dB
• Signal-to-noise ratio: 77 dBA
• Total harmonic distortion + noise: < 0.0025%
• RIAA curve accuracy: ± 0.4 dB / 20 Hz - 20 kHz
• Subsonic filter: 20 Hz at 12 dB/octave
• Connectivity: 1 × RCA (input), 1 × RCA (output)
• Dimensions (W × H × D): 103 × 73 × 119 mm