Old Legendary tubes vs New Kids on the block Amperex/Siemens/Tele vs Psvane/TAD/Shugaung


Posting this on amps board, as pre tubes can make quite a dif on the amp ound. 
I just sent off all my oldstock tubes to a  guy who will sell them for me on ebay,,I am going all ~New kids on the block~ pre tubes. 
I am saying goodbye to my fav~ Amperex BB.s 
The only old stock i am keeping are the 2 tall bottle SQ Philips EC180's which will go in the AU section of the Defy,,i love the cool looking tall bottle of the EC180,'s, But i also bought some Psvane Au's , a sthey look quite impressive with taht double plate at the top,,,Will add some TAD AU's also on wish list, they also have thae cool looking double plate./high tech components.
I will roll the 3 labs, and see wich has the finer resolution/soundstage.
The 4 AX's will have to be the Shugaung, Maybe later on will add the TAD.
The cayin cd17 takes 4 6922's, for those I will go TAD, as they have the cool looking double plates. 
Which brings up this Q...will the old legends hold their top $ prices going forward, as folks begin cking out the new labs offerings, 
Psvane/Shugaung/TAD. 
I've not heard any of the new, as yet, I have the AU's/AX's arriving later this week. Since i sent all my old stock au/ax's off, can't compare to these new labs. Only compare from what i reacll the Defy sounding like  with Old stock. 
However as you guys know i still have that cheap chinese clone which is crippling the Defy's performance. 
The cayin SC6 is still a ways off, so a  true compare could only be made at that time. 
The cayin has 4 AU's, will roll both TAD and Psvane T series AU's. , Psvane has a  new ax out called T series,,,I will buy both the Psvane and the TAD, see which comes out for high resolution of fq's. 
Have you guys heard any of these newer labs, vs the old legends. 
On the power tubes, I have EH KT90's and also chinese KT88's i bought cheap off ebay,,so will roll those  when the front tubes arrive. 
Will not rebias the amp,,it will be a  justa  shortb 10 minute testing.
If I like the 88's over the EH90's,,I will add the Psvane KT88 C version to wish list, The C version is the newer KT88 from Psvane called the Classic 88, the older version is called the hifi 88. 
I will post notes over the comming year as these tests will be ongoing during the year 2020. 
What say you about these new kids on the block?
mozartfan
I say you're going the opposite way you should be going. None of these new production tubes can match tubes from the 50's and 60's. You'll never live long enough to find out, but your new Russian or Chinese tubes will not be around 50-60 years after you buy them and use them that long. Vacuum tubes are definitely one product that proves the old adage "they don't make them like they used to." There are many articles by tube experts you can search for that say the same thing with regard to new vs NOS tubes whether they are output tubes or small signal tubes. New production just doesn't measure up. And, of course, there are a few who say they do. The consensus is that the old ones are far superior in every way.
I bought for future use a pair of the best Shuguang 12ax7's. And a pair of 7025's from TAD. Primarily for my Fender Twin Reverb, though I can use them in my Dyna PAS preamp and two Scott integrateds.
I'm making it work by using  new production tubes combined with careful cabling choices.The wonderful old tubes are mostly priced beyond what I'm willing to pay.