Thank you for the reply. I asked because it is very irritating when the the left and the right tube are not matched/or not evenly rated. The singer tends to veer on the more powerful tube. It is when I wondered why not just make the pre-amp stage one tube so that it will always be even.
Now I learned why two(2) tubes are used for gain stage.
no two tubes are exactly alike in characteristics,
that is why i do not subscribe to the notion of "matched tubes".....
afaik, no such thing with tubes, get 100 samples and you will be lucky to find a pair...
even the two sections of a tube will never match 100% they can come close but never 100%
luckily there are circuit techniques that can mitigate these effects...
so if someone sells me a matched pair, i run away.....