Phono Box S2 Ultra uses a fully discrete, Op-Amp-free design that fosters sonics rarely found in this class. On top of omitting Op-Amps, the selected polystyrene capacitors (known among audiophiles as the ‘holy grail’ for phono preamplifiers) significantly contribute to the clean, clear, detail-oriented sonics that S2 Ultra delivers. With wide-ranging flexibility in gain, load & capacitance, it can handle with grace almost any cartridge you throw at it. Split RIAA equalization creates an ultra-accurate representation of the RIAA curve, further refining what you hear. To protect the circuitry from potentially harmful interference, the S2 enclosure features a 2-layer enclosure comprised of aluminum & steel.

Additional information
Weight 0.57 kg
Dimensions 11.9 × 10.3 × 3.7 cm



  • Audiophile performance
  • No operational amplifiers used
  • Audiophile-grade polystyrene capacitors
  • Precise split RIAA equalisation
  • Switchable Subsonic filter –18 dB @ 20Hz
  • Switchable input impedance/capacitance
  • Four adjustable gain levels
  • Solid metal casing protects from interferences
  • Outstanding sound quality
  • Available in silver or black
  • Handmade in Europe


  • Input impedance: 10, 100, 1k, 47k ohms / 100pF
  • Input capacitance/impedance: 100pF, 200pF, 320pF and 420pF */47kohms B
  • Input gain: 40 and 43dB B / 60 and 63dB A
  • Signal / Noise ratio MM: 85dBV (90dBV – ‘A’ weighted)
  • Signal / Noise ratio MC: 65dBV (71dBV – ‘A’ weighted)
  • THD: <0,0005% MM, < 0,004% MC
  • RIAA-equalization curve accuracy: <0,4dB / 20Hz – 20kHz
  • Subsonic filter: at 20Hz with 18dB/octave
  • Input: 1 pair RCA/phono sockets
  • Line-level output: 1 pair RCA/phono sockets
  • Power supply DC: 18V/500mA
  • Power consumption: 18V/80mA DC

A: typical for low output MC cartridges, B: typical for MM cartridges or high output MC
*Input capacitance is irrelevant for low output MC cartridges.


“The Pro-Ject is the most even-keeled, neutral, detailed, clear phono preamp out of the bunch. It’s very good.” – Randy Messman, Cheap Audio Man