Seeking a Warm 12AX7 Tube for Preamp

I went from JJ EC803S to the Mullard new issue CV4004, and was pleased. Found them to be less bright and a bit warmer, but still lively and musical through the mids.

What preamp did you purchased? Maybe consider getting the lower gain NOS 5751 , they are more expensive than your under $100 price point, but it might be worth giving Brent Jessee a call he does have GE 5751 premium at $110 a pair , or GE 5751 greyplates at $150 a pair and see if they fit the bill for you. He does have other 5751s but they are more expensive.  I use 5751s in my Line Magnetic 518IA integrated as 12ax7s were a bit too much for my ears in it. On the otherhand I prefer 12x7s vs 5751 in my Finale Audio integrated.

I agree looking into NOS 5751 tubes since I use a set in my preamp section. I would contact Brent Jessee for advice since he stocks many 12AX7 type tubes. He has some matched sets that are a bit over $100.

In my profile system page there is a chart for NOS small signal tube ie 12au7,12ax7 etc. its very handy for what you're asking. note its labelled 12au7 but it's the same for 12ax7, 12at7,12au7.