From my own experience I know only 2 types of tubes that sounded freaking good, while they tested poor.
1 NOS Tung Sol 6550 Black Smooth plates
2 NOS GEC KT88
I owned quads from both at the same time and in each quad was 1 tube that tested poor, but they sounded great. How possible? Dont know, it's all beyond me, probably the quality is so high that they still perform until they really die.
THX
1 NOS Tung Sol 6550 Black Smooth plates
2 NOS GEC KT88
I owned quads from both at the same time and in each quad was 1 tube that tested poor, but they sounded great. How possible? Dont know, it's all beyond me, probably the quality is so high that they still perform until they really die.
THX