Best 6SN7 Pre Amp tubes?

The BT are a more open and tonaly ballanced tube in my system than the Sophia's. But, the Sophia's are close.
I've tried every NOS tube on the market and finnaly settled on the Sophia. Then I tried the BT and my quest was over.
Do not buy the BT from Ebay. The ones from Grant Fidelity had much better tone and was much quieter.
I have no affiliation with Grant Fidelity other than a happy customer.

I have the Tung Sol Blackplate that Teajay is talking about. It is a very good tube.
But the OP didn't ask about the Tung Sol, and it didn't take me off the quest for 6SN7's. The BT did.

They are not the same tubes. Or the same factory.
Completely different in every way. The BT is a much larger tube than the Sophia.

The Gold Lion KT88 is a great tube. But to answer your question... yes. You will hear an improvement with the BT CV-181, even in the lesser stages of the VAC amp. You will be surprized at the difference you'll hear in the low level stages.