| Anyhow, the problem is not with Ken Chait or Lamm owners but in the totally foolish expectations that 6C33C might be matched. Well, if you do burn the 6C33C for 50-60hours and do match it by gain, by bias and by currant then you have MORE chance then the tube will age similarly but it will NOT be an assurance. Do you know how many tubes I would need to go over to match the paid of 6C33C properly? I would say 20 tubes. So, I feel that the best solution would be juts to buy a shit-loaded of cheap 6C33C. Match them by gain and discard bias. That is fixed bias, what would be the difference is you get you default current with 70V or grid or 80V.
What I do is to use a pair of new tubes, match them by gain, check the gain each few month and in one year I trash both tubs if the tubes did not develop any other “problematic” signs earlier. The Cat |