Speed Box II

About the Speed Box II

The Pro-Ject Speed Box II is a microprocessor-controlled, quartz-locked speed regulator designed for Pro-Ject turntables that use a 16V AC motor without built-in electronic speed change. It provides highly accurate, stable playback speeds at 33 and 45 rpm, with the ability to play 78 rpm records when the optional accessory pulley is installed. The unit features a metal case for shielding against vibration and electromagnetic interference, LED speed indicators, and a compact design for placement near the turntable. It replaces the turntable's original power supply and includes an external AC adapter. The Speed Box II is not compatible with certain Pro-Ject models that already have built-in speed control or different power requirements.