***Is It Me Or Have Todays Modern Tubes Gotten REALLY REALLY Good***

Never personally used tubes for hifi stuff. But I have played guitar for 30 years and I must say tubes make a huge difference in my various amps of different manufacture. Both power and preamp. Just my experience. Old black plate RCA 12ax7s, 6v6s and 6l6s sound much better than the new variants. I understand it's different for hifi and guitar. I'm just getting into this game and I must say it's quite something. Deciding right now between tube or SS. Anyhow.... I really enjoy the discussions and knowledge shared here. Thank you!

Dear ebm,you are absolutely right: nos-tubes from the late ‘50s and the early ‘60s are the best. The voices ,instruments ( piano, guitar ) sounds much more natural than the new ones.

Since my power amp and preamp both use 6SN7GTBs, I've been enjoying NOS RCAs, Amperex, Sylvania "chrome domes," and new Tung Sols...and the differences between 'em all. An Amperex sounds great in my amp, the RCAs and Sylvanias in the preamp...this will likely change at some point and hey...that's just fine and I dig it.

I'm laughing at the poster who stated that after a few hundred hours, NOS tubes lose their bass.  I have small signal tubes which have lasted over 6,000 hours in conservatively rated gear (versus ARC equipment which especially kills power tubes-I know I had several ARC amps and my friend has the same issue). 

I had to roll 6SN7s for cathode followers.  The Russian stock all sounded dreadful, thin, bright, no bass.  I ended up with 1950 Raytheons although Ken-Rad and RCA sounded similar.  The Chrome Dome Sylvanias were also excellent but tipped up in the highs for my equipment.  

I rolled 6DJ8s for my EAR Acute.  The latest stock tubes EAR uses for it are quite good but the earliest Amperex are superior.

When I used the EAR 864, I had to roll the tubes to obtain superior performance.  

If I purchased a VAC amp, I probably would only try to roll the 6SN7 tubes since the amp is voiced for the supplied tubes.  I agree that many modern tube equipment is voiced for current tube production and won't benefit from NOS tubes.  NOS power tubes are rare and expensive.  NOS 6SN7s are not especially rare and expensive, particularly 1960s versions which are still very good.  RCA used the same tooling and similar production methods for that tube for it's entire run. 

@fleschler - a real never used old small tube should have long life But, for what used to be a common tube, like a 12ax7, I suspect most of the Telefunkens being sold as NOS are just ’tests as new’ which does really tell you how much mileage they really had before you installed them.