It is a proven fact in audio, better power supplies facilitate better sonic performance. Pro-Ject linear power supplies Power Box RS Uni 1-way (for one component) and 4-way (up to 4 components) were developed to make this improvement available to owners of 20V RS Series gear. A linear power supply consists of a massive toroidal transformer with shielding between primary and secondary windings, which acts as an isolating transformer and prevents penetration of interference from mains from reaching the audio circuitry. The transformer has a much higher power reserve compared to the standard power adapter, very low output impedance with a large filtration capability. What you hear is improved soundstaging & imaging propelled by silent backgrounds, also making micro-detail more available to your ears.

*Please note that Power Box Uni 1-way should never be paired with Phono Box RS due to voltage incompatibility.

Additional information
Weight 4.8 kg
Dimensions 19.5 × 20.1 × 7.2 cm



  • Purest & cleanest power using non-switching power supply
  • Soft start system avoids current inrush in primary winding
  • Audio type toroidal transformer
  • Main isolating transformer with copper foil shielding
  • Secondary voltage rectification with precise regulation
  • High filtration capacity (10.000 µF)
  • Low ESR capacitors
  • Low noise components with surge protection
  • Available in silver or black
  • Handmade in Europe


  • Input voltage: AC 230V/50Hz IEC C15 connector (120V/60Hz US)
  • Output voltage / current: 1 x 20V / 3A max.
  • Filtration capacity: 1 x 10.000 μF
  • Output voltage ripple rejection: better than 75dB