Tubes for Jolida Fusion Preamp


I have a Jolida Fusion pre which takes 2 12AX7 and 2 12AT7 tubes. Looking to upgrade from stock tubes and request herein recommendations. Thanks.
mesch
Wolf is correct and not paranoid... the dealer must have a return policy.
NOS can mean New Old Stock or it can also mean the tube was used in a
medical or military component in the 1950s for a short time and then was
put on the market for sale as new. The dealer would be unaware and test
the tube and it may still test as new.
I submitted a further response on Friday which has yet not been posted. Yes Lowrider I had mistaken you for another, sorry. Anyway as an update I have decided on the following route:

I have searched the web sites of TCtube, thetubestore, and Brent Jesse and will likely do business with them. The Brent Jesse site was most helpful in describing tube build, nomenclature, and sonics.

Given the possibilities are vast and the price range wide, I have decided that I will call the Jolida preamp person and get his opinion. Barring the result doesn’t influence me otherwise, I am leaning towards purchasing from Brent Jesse a set of GE blackplate triple mica tubes for about $200 a set (all 4 required tubes).

I will update everyone as to purchases and impressions. Thanks again for the advise.

Wolf, can’t believe the gluten free tubes are the fave throughout the Great Plains states.
I'm happy to report that the Gold Lion Matched and Balanced (including triodes for another 5 bucks each) Gold Pin Premium 12Ax7s sound amazingly better than anything I've previously used in my Jolida 502p...and they're barely broken in. Maybe the hype is true after all.
Wolf, thanks for the followup. Have not yet moved on tube purchase, will soon.
Well, I ordered a set of Mullard tubes. CV 4024 (at7) and CV 4004 (ax7) platinum grade from Upscale Audio. Was looking to warm up the upper mids and lower treble and was advised they would do that. I will get back to everyone after a comparative listening session. It is likely that these will not be the only tubes I purchase, just my 1st foray into tube rolling. Thanks again.