The Rega IOS is simply one of the finest moving coil phono preamplifiers ever designed. The first stage is a step-up transformer with selectable loading for your choice of MC cartridge. Then there are two separate Class-A amplifier sections to drive the high and low frequencies of the passive RIAA equalization stages. Then the final output is driven by the purest, most natural analog output stage. This provides for the reproduction of the all the subtleties in your music, as well as the dynamics and speed necessary to experience the realism necessary to create the illusion of a live performance in your listening room.