Hello,
I run with the Callisto and Io and for the longest time, I was not using matched pairs of 12ax7's or 6922's. The problem I have had with Tele 12ax7's is that none of the ones that have crossed my path work well (read: ultra low noise) on the first input stage of the Io.....all other stages this is not an issue. For now I use EI 12ax7's on this first stage until I find a pair of low-noise Tele's or Mullards to go here. The Sovteks are a bit fatiguing after hearing these other tubes.
Just recently I got a tube tester and was able to match pairs in terms of signal strength. I used all the higher tested tubes in the early stages but other than finding a couple tubes that measured weak and thus were replaced, the sound is all the same.....very lush! But there is no way for me to know the true outcome if I put in non-matching tubes. I guess I'll have to try this as I have the ability to match or mismatch accordingly. So I will have to do this and report back.
John
I run with the Callisto and Io and for the longest time, I was not using matched pairs of 12ax7's or 6922's. The problem I have had with Tele 12ax7's is that none of the ones that have crossed my path work well (read: ultra low noise) on the first input stage of the Io.....all other stages this is not an issue. For now I use EI 12ax7's on this first stage until I find a pair of low-noise Tele's or Mullards to go here. The Sovteks are a bit fatiguing after hearing these other tubes.
Just recently I got a tube tester and was able to match pairs in terms of signal strength. I used all the higher tested tubes in the early stages but other than finding a couple tubes that measured weak and thus were replaced, the sound is all the same.....very lush! But there is no way for me to know the true outcome if I put in non-matching tubes. I guess I'll have to try this as I have the ability to match or mismatch accordingly. So I will have to do this and report back.
John