Why are older tubes so much sought after

if you speak to many manufacturers of tube amps, tube cd players and tube preamps, in production today, you will be told that replacing the tube with nos varieties will have a mimimal sonic effect. bat and mcintosh are two examples of this.

i have found that many current poroduction tube components are relatively insensitive to changes in tubes.

hi eldartford:

you made a very insightful staemnet when you referred to stereo systems as "musical" rather than "reproducing" instruments.

in fact, all components are imperfect. thus at best, all stereo systems are imperfect reproducing instruments.

doesn't it make sense to select the nature of imperfection rather than settle for whatever accrues from configuring a stereo system in an attempt to create accuracy ?

obviously tube selection may be a way to voice a stereo system to suit one's taste.