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 3 responses by kt_88

Sorry I should have mentioned the pre I wanted to run the tubes in is a Rogue 66. I will also e-mail and find out what type of tester was used.
Here is the necessary info;

41/40 (JTL 12AU7 with "D" shaped getter ), 37/36, 28/32, & 28/35. All measurements recorded on EMC 205 tester, where 40 is spec for a new tube and 25 is "acceptable" as 65%.