Thinking about buying a different tube preamp...

Many vintage 6SN7's from companies like Ken Rad, Brimar, and those silly metal base Sylvanias are microphonic. It's going to be very tough to get low microphony quality ones as we move down the road. The regular Shuguang 6SN7 sounds fine to me. The Russian ones are more durable. I cast a suspicious eye on some current production tubes that are being priced so high. I'm not sure how to reconcile the increase in price.

My inventory of vintage 12AU7's from Mullard, Brimar, Siemens, etc is about 13,000 pieces. My 6SN7 inventory that is TRUE low noise low microphony is about 500 pieces.

The reason is that most stocks of vintage NOS tubes comes from ex-military goods and 12AU7's were used extensively.

I've been doing a bit of searching and have come up with the Northern Electric 6sn7's and the GE 6sn7GTB's for their claimed low noise and extended highs.
I tested my Sophia's on the ancient tester my brother gave me years ago and found one of them questionable.
I like detail and extended highs, with good bass as well. Read about the TJ Full Music 6sn7's that were described this way. So far I'm leaning towards the NE's and GE's.

QUIET!! Put in a pair of GE wide grey plate 6SN7GTB tubes and they are so quiet. I'm very pleased. Was actually thinking there may be a problem with the preamp since both sets the seller sent me with the preamp were noisy. Thought I'd have to send it in for a check-up, and was prepared to spend some serious cash on a solid state preamp. Was leaning towards a Pass Labs XP-20 and almost ought one the other day. Glad I waited to see how these GE's sounded. Will wait for these to break-in before I try more. :)

I've been looking for the Shuguang black treasure cv181s and find they are for the most part available only in the East. Can anybody point me to reputable seller?