tube match?


Can anyone tell me how close the readings on tubes need to be to run in the same pre? I have the following readings, I'm wondering if any are close enough to run in a 2 tube pre.

37/36 41/40 28/36 28/32 they are tung-sol 12au7's don't ask me which reading is for what, I don't have a clue. These are the numbers written on the tubes.
kt_88

Showing 1 response by fletchj

Most often, tubes that match, within 10% is acceptable. If the numbers, came from the same tester, with the same settings, then you can use them, to match the tubes. The higher the numbers, the better, the tube tested.