Most Musical 6NS7 tube for a Preamp?

The best sounding 6SN7 I have tried in my Supratek Syrah preamp is the cheap Russian  military black base OTK.They are a bit microphonic however.They do sound very dynamic and vibrant though.The worst I have tried is the Shugyang Treasure CV181-Z which sounds quite muffled and dull.The USA Sylvania 6SN7GT black base is decent but a bit lifeless.What would be nice is something with the dynamics and vibrancy of the Russian military and the quietness of the others.Any suggestions.

By the way the Supratek is a fantastic sounding preamp.I own a Supratek Cabernet 300B as well.

@aldnorab Don Sachs D2 linestage takes 4 6SN7s that might be a little expensive to run if you want the best tubes. I have tried Ken-Rad VT231, they are well, not the smoothest in the HF but good tubes none of the less.

@jtgofish If you are looking for dynamic and vibrant in 6SN7 tubes you should look elsewhere, use 6CG7 with adapters in place of 6SN7s

The best 6SN7s I have heard were the Tung Sol round plates. These were used as drivers in a slightly brighter sounding power amplifier. Perhaps one of the best buys are the Hitachi made, often rebranded, 6SN7GTB tubes.