The Phone One RIAA preamp employs a two-stage low noise gain block JFET OPAMP topology which has the outputs of each OPAMP actively locked into Class A with JFET active loads.

The first stage acts as the main interface to the MM or MC cartridge and provides selectable input impedance and gain settings from 40db for MM and up to around 64db for MC, all adjustable via on-board SMD dip switches. The second stage acts as the main RIAA active filter with an option for a passive input rumble filter if so desired.

Before exiting the main output at a nominal output of around 1-volt RMS.

The Phono One is finished in an all aluminum case with a diamond hard powder coated black finish.

With a AC mains filtered IEC power entry socket and Input-Output connectors on the back of the case and a push button power switch on the front.

Outside case dimensions: 200mm-Wide x 210mm-Deep x 80mm-High