I expect that isolated testing / fine-tuning before
feeding the components
into the production area would help a lot, though. Screen out the faulty /
really bad stuff, and tweak the marginal bits to produce components that are a
bit more uniform in performance.
Stability is also a huge issue. Early tubes generally needed constant
adjustment while operating. Screening Audions would help somewhat, but
five minutes after the screening of new parts, you would end up with a
bunch of mismatched tubes again.
--
Will