PRO-JECT TUBE BOX S2

Pre owned. In excellent condition. Free from evident signs of wear. Original packaging not included.

Tube Box S2 is a compact phono preamplifier designed to deliver high-end performance with an authentic tube sound signature. This model stands out thanks to its fully discrete circuit design without operational amplifiers, an engineering choice that allows for a more natural, musical, and detailed sound reproduction. The use of two replaceable ECC83 tubes also enables tube rolling, giving users the possibility to tailor the sound character according to their listening preferences.

The sound presentation is warm, full-bodied, and relaxed, with rich and engaging midrange frequencies typically associated with larger high-end tube phono preamplifiers, while maintaining an extremely compact form factor. Tube Box S2 supports both MM and MC cartridges and offers multiple gain settings that can be selected directly from the front panel, ensuring precise adaptation to different analog setups. It also provides five variable input impedance settings dedicated to MM cartridges, while the fixed 47 kOhm setting is ideal for high-output MC cartridges.

RIAA equalization is handled through a precise two-stage passive/active design developed to ensure faithful and accurate analog signal reproduction. The ultra low-noise circuitry with FET input stage helps preserve sound purity, while the dual mono configuration optimizes channel separation for improved stereo imaging and definition. Polystyrene capacitors are used wherever possible for their sonic qualities and long-term stability.

The front panel also features gain adjustment and a subsonic filter designed to reduce unwanted vibrations and extremely low frequencies that may affect listening quality. Gold-plated RCA connectors ensure reliable connections and improved signal transmission, while the external power supply works alongside multiple carefully filtered internal power sections, including a high-voltage anode power supply engineered for stable and quiet operation.

The aluminum and metal sandwich chassis, aesthetically matched to the DS2 line, not only provides elegance and durability but also effectively shields the circuitry from vibrations and electromagnetic interference, contributing to cleaner and more accurate sound reproduction. For users seeking even higher performance, Tube Box S2 can be paired with the optional Accu Box S2 power supply upgrade.

Technical specifications:

• Tubes: 2 x ECC83 (12AX7A)
• Input impedance: 10 Ohms; 100 Ohms; 1 kOhm; 2 kOhms
• Input capacitance/impedance: 47 pF; 147 pF; 267 pF; 367 pF; 487 pF; 587 pF / 47 kOhms
• Input gain: 40 dB; 43 dB; 50 dB; 60 dB; 63 dB
• Noise floor: 80 dB (A-weighted) at 40 dB gain; 75 dB (A-weighted) at 50 dB and 63 dB gain
• Total harmonic distortion (THD): <0.02% at 40 dB gain; <0.05% at 50 dB and 63 dB gain
• RIAA equalization accuracy: +/- 0.4 dB / 20 Hz – 20 kHz
• Subsonic filter: 20 Hz with 18 dB/octave slope
• Input: 1 pair RCA/Phono sockets
• Line output: 1 pair RCA/Phono sockets
• External power supply: 18 V / 1,000 mA DC
• Power consumption: 470 mA DC; <1 W standby
• Dimensions (W x H x D, including sockets): 103 x 73 x 131 mm
• Weight: 410 g without power supply