Ed -- THOUSANDS? I've got eight.... Think of it this way, once upon a time, the large majority of military hardware was dependent these tubes. Consequently, a good bit of the best minds and vast military-industrial complexes of the world were devoted to making the best tubes conceivable, at any cost. Now, at that time, due in part to the (im)precision of manufacturing, making tubes was at least equal parts art and science. Today, the guys who perfected the "art" component of it all are mostly not around or just not doing it any more, so -- to an appreciably real extent -- the art of making vacuum tubes developed at the height of the cold war is a bona fide "lost art." The literal life and death urgency to making perfect tubes is gone, and there is nothing that will bring both the resources and talent back into the equation. Now, you could easily argue that modern advances in precision manufacturing can and have more than made up for any supposed lost "art" in making tubes, and that modern tube making (although an esoteric and fringe industry, to be sure) is more than up to the task. Listen to both and decide for yourself. One thing is sure, though, (whether it is through massive, consensual group delusion or some objective, quantifiable truth) enough people believe that there was some sonic magic captured in the tubes made back in the day that hasnt been equaled in the current batches. Luckily, again because they were just so damn important at the time, folks made a lot of extra tubes back then and stockpiled them, which is why there are New Old Stock (made then, yet unused) around on the market. Ive got Mullard gold pin MIL SPEC (Military Specification, I assume) NATO tubes in on of my preamps that came in the original NATO packaging. Hey, even if they didnt sound better (and they do), thats pretty cool.
