Made by US defence contractor Raytheon, the 6418 valves used in the X1 were originally used in the guidance system of the Tomahawk Missiles. These military spec valves were impervious to the effects of nuclear radiation. We use these exact same valves in all our amplifiers. Made by Ratheon in 1984, unpackaged and unused until now. You'll also find these valves in some of the best studio microphones such as the Audi Technica AT3060.
The X1 enclosure is CNC milled from solid aluminium. 2mm aluminium front and back plates joined with stainless steel fasteners gives the X1 a beautifully rugged feel. The circuit board uses extra thick 2 ounce copper tracks for better conduction. Metal film resistors and low ESR capacitors keep the electronics very low noise.