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

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.

@buellrider97 , you and me both!

Also Apple, Google, and Amazon!

Wow, $125 each.

At least you got four. Could have bought just two!