Additional Preamp Tubes


I am looking to purchase an additional matched pair of NOS tubes for my PS Audio BHK preamp. I currently own Brimar CV4003, Telefunken Medicals & Siemens Nickel Plate. 
When I began building my system 3.5 years ago, I wanted revealing - accurate. Now I want a tube that is more musical / warm, similar to the Brimar’s with a touch more warmth. 
My system: Aurender N150 > Briscati M3 > BHK > Moon 760A > KEF Reference 3’s. Rega P8 / Hana ML > Gold Note PH 10 on analog. Cables are Kimber Select from sources & Transparent Ultra’s pre > amp > speakers.  
ChatGPT recommended Mullard CV4003. There is a pair on eBay from Valve Tubes. Please let me know your thoughts on this and other potential tubes, and if you have any experience with Valve tubes. Thanks!

signaforce

FWIW , RF Parts company in San Marcos, Ca has nos RCA 6189’s black plates for $34.91. Sorry I wasn’t able to post the link with my iPhone. 

Don't rule out 6V tubes. There is a jumper to change inside the chassis. When I had a BHK pre I liked 6 volt tubes best, though I don't remember which tubes in particular. But a problem I had with 6V in my unit was noise. But I think that was not universal.

@buellrider97 ,

Mike, that's right! You're the one with the legendary Telefunkens!

Man, what a score...

@thecarpathian , Ha Ha , I should have bought Microsoft when it first was available. The guy had 10 of those tubes at $125 each , bought 4 should have bought them all. It’s sad what’s happened to nos tubes in the last 10 years. 

Checking my stash, I have 5 Mullard cv4003’s, of which 2 are 8136’s and all kinds of others.

All Mullards from Upscale Audio and been just sitting in their little boxes for years. Think it’s time to thin the herd.