12at7 - brimar yellow "t" label 6060s circa 1954
12ax7 - mullards d "getter" circa 1957
6550 - tung sol black plate triple top getter circa 1957
HUGE difference
i like it better now tham my friends mac
12ax7 - mullards d "getter" circa 1957
6550 - tung sol black plate triple top getter circa 1957
HUGE difference
i like it better now tham my friends mac