looking for a tube preamps that doesn't sound like SS

Conrad Johnsons from the 1980's.

I have an MP-3 from atmasphere, great sounding preamp and just swapping different 6SN7 you can get different sounding profiles, atmasphere customer support is great as well in case you have questions or need service.
Actually I just realized you aren't listing your amp or speakers so any recommendations from me or others are not very valuable. 
Your amp kind of will determine which tube preamp will fit best. 
The MP-3 impedance will match most amps and if your amp is balanced then it will be an even better match 

I am not sure why you would a warm old school sound unless you had some deficiency in your system that would cause you to want to thicken things up. A list of your components would be helpful due the fact that a change elsewhere could solve any problem you might have. Of the advice above I dont think that the Berning, Rogue or Schiit products would give you what you want. The Berning is a wonderful preamp but it isnt particularly warm but more linear/neutral. Suffice it to say that I am not a fan of Rogue and of Schiit even less. I think that the old CJ preamps and the Joule are good units for what you want. I prefer the Joule to the old CJs.

I forgot to mention that Audio Note Kit preamps are very good and lean toward the warm side but not obnoxiously so. You can buy them as a kit or have them assembled.

From what I read oglethorpe is on the right track with the tube preamp.
I’ve read pretty much everything on the Don Sach pre, which looks really special.

Anyone have experience with Erhard Audio, Aretha preamp?
I’m interested in a tube pre with tone controls. Would also like a headphone jack, but would that require another amp within the pre?

http://www.erhard-audio.com/Aretha.html