In additon to Ga5556's point "matching" is different for different circuits/amps. I just bought an old Citation to fool around with. Matching cathode currents, which is what most people mean isn't that important. You do not want them way off but you are looking for close Gm (transconductance).
I'm harldly an expert on all the different circuits and such but matching is not one thing and also a lot of tubes are matched in conditions that do not match how they are going to be used (voltages/currents) and so the "matching" tells you less than one would think and often they are tested/matched without proper warm up etc...
I remain,
I'm harldly an expert on all the different circuits and such but matching is not one thing and also a lot of tubes are matched in conditions that do not match how they are going to be used (voltages/currents) and so the "matching" tells you less than one would think and often they are tested/matched without proper warm up etc...
I remain,