The 7027A has been used in many vintage Ampeg amplifiers, such as the Portaflex B15S, B18N, B25, V2, V3, V4, V4B, VT22, or VT40 and in U.S.-made audio equipment. The 7027A is close to a 6L6GC, but due to a different base diagram it is not 100% compatible. The TAD 7027A is a heavy duty version, perfectly designed for use in demanding applications. It delivers the power and dynamics you need to bring your amp to its best original tone.