tube for ARC LS2B II preamp


I'm looking for advice as to what might be a warm sounding 6922 tube for my ARC LS2B.  I've recently begun listening to a lot of jazz and I'm finding that the sound is a bit bright for my tastes.  I'm currently using a Tungsram tube which sounds good while listening to most types of music, but not jazz.  Perhaps a single tube will not help with the brightness but any thoughts would be appreciated.  Thanks

My equipment in addition to the ARC preamp:  Bel Canto Ref500 amps, Cayin CD-50T, Vandersteen 3A Signatures.
For vintage tubes, I suggest you google "Joes Tube Lore".
He has tested many different 6922/7308 tubes and has posted his opinion.
It is a good starting point.
Mullard's are more of a softer, euphoric sounding tube and may be to your liking. 
You could purchase several pairs of different ones and those that don't meet your needs could be resold at a very minimal loss.
I can't help you with New reissue tubes. 
Either way have fun and enjoy the journey.
I always liked a GE 6DJ8. I think that it will give you the warm sound you are looking for!
Amperex Trumpeter/Bugle Boys always seemed very "soft" to me.

6922 tubes of whatever brand are "neutral", that's ARC's claim to fame; maybe you need a different preamp, like CJ for example.
Some listeners find the LS2 (and other ARC mostly-solid state models---the LS2 contains only one tube) to sound a little "dry" as well as bright (leading to their sound being characterized as "white"), so a tube that helps the pre achieve a more "liquidly transparent" sound is worth looking for. Which such tubes are I don't know.