I have now listened to the Amperex Orange Globes tubes from 1969 for a couple of days and I must say they are amazing.
I got them from mercedesman6572 on eBay.
My audio chain: FLAC -> Asus Xonar Essence ST RCA -> Schiit Lyr -> Toxic Cable 10ft OCC Cryo Silver/Copper -> Audeze LCD-2
I am comparing them to the stock GE 6BZ7 and the JJ E88CC.
My thoughts mirror the impressions that Iamnothim wrote earlier in this thread.
The first impressions I had were actually quite negative. The mids seemed thin and the treble was downright harsh. I was really hoping that burning them in would improve them. I let them burn in for just over 30 hours and boy was I in for a surprise.
For only 60 bucks, they were a steal. Not only do they add an entirely new layer of detail, they also shaped both the treble and the bass right up. The mids also seem more ... uhhhh.... betterer. Vocals seem a whole lot more real, as if the singer is right in the room with you. Usually people go on about feeling the need to listen to all their music again with even the tiniest upgrades. I did not do that, but I did however, listen to all my Pink Floyd albums again. For some reason, while it may be psychological, the difference seemed to be biggest with their albums. The song that stood out to me the most is "Mother" from The Wall. It seemed like the entire band was right in front of me.
These tubes have added a new level of enjoyment to music for me. They are sold out where I purchased them from, but if you find them anywhere else, buy them. They go quick.