Sophia KT88 vs. Psvane KT88

I might be a tad premature here but I was wondering if anyone has any experience with these new Sophia tubes. I only found out about them a few days ago. I did contact the company and was told they do have a limited supply of KT88's. They said this is a new product for them. They quoted me a price of $400.00/pr. Seems quite steep for new production tubes. The Psvane product is less expensive. Any info you have on personal experience with the Sophia tubes, where they are made, how they compare to the Psvane products etc. would be helpful.
You can search TJ Full Music carbon plate KT88 online to see any further feedback. They are from the same factory.

Carbon plate KT88 is hard to make because they tend to be overheated, hence they are expensive.
KT 88's are relatively difficult to manufacture - that's why modern production KT-88's are reputed to be problematic and why there are a lot of bad ones on the market.

The Sophia tubes are manufactured by Full Music in China, yes, but Richard does additional testing to cull out the poorer quality ones. Basically, what you're paying for when you buy a Sophia tube is Richard's testing. I'm not knocking Full Music, as they make most of the best production coming out of China.
The black treasure KT 88z are amazing, i just got it in and it changed the way my avantgarde trio/audiopax sound . The difference is astounding!
quote: "Sophia Electric tubes are being made and tested by US audiophile quality standard. Sophia Electric engineers are monitoring each every pairs of tubes being sold with a complete quality control system and book keeping.

Sophia Electric design and refine each new tube model before put into production. Only the best of the production would qualify for Sophia Electric's high standard.

Those think they could just get tubes from another channel with the same quality of Sophia Electric, they would get burned soon or later."

I think it worth every penny for Sophia Electric tubes. The Chinese factory quality control was not there nor sound like there is. If the factory wish to sell every pair made, and with a small discount to the Sophia Electric's premium price, will you(the US audiophile) buy it?

So everyone is clear here, Washington_highend_audio is in-fact Sophia Electric. I live by their office and met Richard from Sophia Electric during my visit to hear Sophia Electric tubes and monoblocks some time ago.

They are a re-brander / importer for Chinese gear. If they claim to test the tubes, I would insist on individual proof sheets for each tube to prove matching / testing. I have never heard of Sophia Electric offering that. I have owned Sophia's mesh plate 300b's, and they came with generic 300b proof sheets, not actual proofs as one might find with Western Electric and many other premium brands.