The TAD KT66 delivers old-school tone out-of-the-box. A faithful reproduction of the great British KT66 by MOV (MO Valve), GEC, Genalex or Gold Lion. This tube made the Marshall JTM45 Plexi Amps famous in the 1960s and helped the Quad Hi-Fi amps achieve their legendary status. Talking of legends: SRV created his gigantic guitar tone with the help of KT66s in his Fender amps. This tube is the “real thing” with a large curved glass envelope and a rounded brown base.