Why do NOS Tubes sound better than new tubes?

Is manufacturing really that backwards in todays techno world? What is the real reason that todays tubes cannot equal the tubes of yesteryear?

tubed108-26-2011 2:39pm

dopogue Details Discussions Posts This discussion Message User 1,773 posts 08-26-2011 at 09:10pm Copy Comment URL Report Comment Edit Delete Agree with Tpreaves. I've replaced Mullard xf1 EL34s as driver tubes in my SET monoblocks with current-production Genalex Gold Lion KT77s because they sound better. OTOH, NOS tubes are often preferable. But it's not a sure thing and always worth trying the new ones.