Built with an array of muscle-flexing features like a Multi-Watt assignable power amp which allows for operation at two or four vacuum tubes, selectable diode or tube tracking, and a fixed bias select switch for no-hassle operation, the Mesa Boogie Roadster Guitar Amplifier Head is a twin personality monster. The Roadster's four selectable channels take you on a journey through the world of guitar tone from sparkling cleans down to a gain-laden roar with Raw, Vintage, and Modern modes on each channel for having a vintage Tweed, throaty British, and searing modern tone on easy call through the accompanying foostwitch.