pro ject rpm 3 carbonManual turntable with 10'' carbon tonearm RPM 3 Carbon uses evolutionary improvements to enhance the performance of the RPM series: A low resonance chassis supports an inverted bearing with a ceramic ball for even further reduced rumble. An external 15V AC motor is driven smoothly using an ultra precision AC generator with DC power supply for further improved speed stability. A 10" S shaped tonearm tube is made of carbon fiber, aluminum and resin.