I’m sure many of you don’t even know about this intriguing analog micro machine. Some absolutely gorgeous shots of Audio Note (UK) IO Ltd Field Coil cartridge and its PSU, courtesy of the man with the golden lens, Carlo Marengo from Audio-philia in Edinburgh. IO Ltd has extremely low output of just 0.04mV and field coil principle demands quite a different approach. After further extensive research the optimal magnetic circuit was found to be electro magnetically generated. This, however, requires a separate DC power supply and is very costly to implement. Therefore, only a cartridge producing the absolute ultimate in performance could employ such a system… and the IO Limited was born.