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

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.

You are correct.  That's why I purchase industrial versions of Amperex 6DJ8s and RCA 12AU7 clear-tops.  Telefunkens were generally used in home audio and notorious for being faked and well used despite good test scores.  It is a problem but I have had 40+ years experience using NOS tubes in my gear.  Luckily, most of the tubes in my current gear are either rated for 100,000 hours purchased new (subminiature tubes for my pre-amp and phono stage) or exotic but common new tubes from the 1980s (6BG6 Russian output tubes at $6-7 each).  

I can only speak for my experience, have atmasphere ma-1 and mp-3, rolling 6sn7 and similar on pre amp discovered that the cv181-t black treasure on the pre amp sounded amazingly good compared to stock and nos chrome domes, well that's not the end of the story. When NOS high quality and conductannce used these were better than the black treasures tubes, not all NOS are created equal that's my conclusion.

When Sylvanias were rolled into the ma-1 and entire different sound developed, more e coherently sounded was implemented

Very very happy with my amps and pre 

One of the worst NOS brands is GE.  They were always mediocre.