Speed Box S2 offers a functional and convenient upgrade for older Pro-Ject turntables with 16V AC motors and without built-in speed control. It acts as an AC generator for the turntable, replacing the fluctuant power consumption from a standard 16V power supply and regulating it. The result is a clean power signal and speed stability that allows the motor to perform optimally. The added convenience is that the S2 can shift frequency for easy electronic speed change between 33 and 45rpm with the push of a button.

Speed Box S2 makes use of high-quality materials in the quartz-controlled oscillator and filter circuits. Housed in a 2-layer aluminum/steel enclosure that looks great & shields the internals from interference, it delivers a sonic upgrade that you’ll hear immediately.

Connection is simple. The S2 includes the cable that connects it to the PSU input on your turntable. Furthermore, 78rpm discs are supported with the add-on Speed Box motor pulley, which allows toggling between 33 & 78rpm. Buy now and an extra year of warranty by registering your Pro-Ject product here.

Additional information
Weight 0.56 kg
Dimensions 10.4 × 10.3 × 3.6 cm



  • Nominal speeds: 33 and 45 r.p.m., optional 78 r.p.m.
  • Quartz oscillator Speed stability: +/- 0,001%
  • Length of power cable: approximately 40cm
  • Turntable connection: 16V/AC 190mA max. (3W power consumption max.)
  • Outboard power supply: 18V/500mA DC, suitable for your country’s mains supply