It has its roots in the high-end amplifiers made by Michaelson & Austin, the first company run by Musical Fidelity founder Antony Michaelson. Since then he says he's had a desire to make a valve-based preamp to match the power amps the company was then making.
A total of 14 selected ECC81 valves are used in the unit, which is said to give distortion of just 0.0035% from 10Hz to 50kHz, regardless of volume level, and a frequency response flat to within +/-0.5dB across the same range.
Two pairs of valves are are used in the output stage, ensuring that it can drive "any conceivable amplifier or length of interconnect cable.
The Primo is finished with a front panel machined from a single billet of milspec aluminium, with badges made from medical grade stainless steel, and the remote is also machined from solid, as are its buttons.