Many companies supply average tubes in their amps as they know that most of us will roll them any way. Chinese tubes are a mixed bag.....while some are very good, many are terrible ( especially those generic signal tubes with stars on them ). There is no one tube that sounds the "best" in a given amp as it's an individual decision as to what sounds best to you - this is why "tube rolling" has become a hobby within a hobby.

The finest tubes produced today have difficulty matching the best tubes of yesteryear. With the advent of transistors the great American tube factories were closed, dismantled and the tooling lost forever.