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Estimated price (community-sourced)
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The Pro-Ject Tube Box S2 is a high-end phono preamplifier designed for both MM and MC cartridges. It features a fully discrete circuit design without any operational amplifiers (OpAmps) and includes two replaceable ECC83 tubes (12AX7A) for tube rolling and sound shaping, allowing users to customize the sound signature. The preamp offers precise RIAA equalization in two parts (passive and active), ultra-low noise circuitry with an FET input stage, and dual mono circuitry for optimized channel separation. It has multiple gain settings (40, 43, 50, 53, 60, and 63 dB) selectable on the front panel, and five variable input impedance settings (10Ω, 100Ω, 470Ω, 1kΩ, 2kΩ) for low-output MC cartridges, plus a fixed 47kΩ input impedance for MM and high-output MC cartridges. Input capacitance can be adjusted (47pF to 587pF) via dip switches. The unit includes a front-panel subsonic filter button (18 dB/octave roll-off at 20 Hz) to reduce low-frequency rumble. The chassis is made of a sandwich aluminum/metal casing that protects against vibrations and electromagnetic interference, available in black or silver finishes. It uses gold-plated RCA inputs and outputs and is powered by an external 18V/1A DC power supply. Dimensions are approximately 103 x 73 x 131 mm, and it weighs 410 g without the power supply. The Tube Box S2 delivers a full, relaxed, and laid-back sound with lush mids, comparable to much larger high-end tube phono preamplifiers. It is handmade in Europe and represents a compact, high-end solution for vinyl playback.
Analog signal output specifications
Phono stage specifications
Size, weight, and appearance
Specifications are community-contributed and may not be accurate or complete. Verify all details with the manufacturer before making purchasing decisions. Terms & Conditions
Components that show up alongside the Tube Box S2 in real systems. A verdict means the pair has been checked for compatibility and headroom — open it to see how the two get along.
The closest alternatives on specs, description and the systems they turn up in, with the specs they share set side by side.
The Tube Box DS2's signal-to-noise is 88 dB against the Tube Box S2's 80 dB, its mc gain 65 dB against 63 dB, and its thd 0.040% against 0.020%. Both share mm gain (40 dB).
Both turn up in the same documented systems.
The Limetree Phono II's signal-to-noise is 82 dB against the Tube Box S2's 80 dB, its mc gain 66 dB against 63 dB, and its thd 0.001% against 0.020%. Both share mm gain (40 dB).
The Nano Phono V2's signal-to-noise is 81 dB against the Tube Box S2's 80 dB, its thd 0.006% against 0.020%, its mm gain 34 dB against 40 dB, and its mc gain 54 dB against 63 dB.
The MiniMax's signal-to-noise is 90 dB against the Tube Box S2's 80 dB, its mm gain 42 dB against 40 dB, its thd 0.100% against 0.020%, and its mc gain 57 dB against 63 dB.
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