Same amp as a Supro Taurus Model S6625... Here we take a rusty, "farm fresh" late 1960s vintage tube Valco Gretsch G6157 Super Bass head and modify it into a hot-rodded Supro Thunderbolt S6420! We will follow every step of the process from diagnosis of the Gretsch and repair of the original head, to the decision to modify and the modification process, and finally we will hear how it sounds before and after the mods. This is a long video, but we cover a lot of ground, so grab some popcorn for this one!