The Catalinbread Formula 51 is a new addition to the Portland company's family of Tweed-style amp-in-a-box pedals, already comprising the Formula 5F6, voiced after a '57 Deluxe, and the Formula 55, inspired by the preamp section of the Tweed Deluxe. The 51 recreates the tone of a Tweed Champ, a one-knob, 4-watt combo amp released way back in 1948.... Click on the title for more