help me select a single tube to "calm down" a preamp?

Mejames suggestion of the Telefunken echo my first or second choice as well. Be aware that the correct number for the Telefunken version of this tube is 6DJ8. The 6922 Tele is not only extremely rare, it does not have the sonic signature to solve your problem.

Another high on my list is the gold pin Mullard 6922. Just be sure its the British version, not one manufactured in another country with the Mullard logo.

It is sometime necessary to attack this type of problem from two angles. If you list the other tubes in this unit, I will suggest replacements that work with the 6922 and bring you closer to the tonal balance and resolution you are seeking.

Go and buy yourself an Amperex Bugle Boy 6DJ8 and all your problem will be solve.

I second the vote for the bugle boy 6dj8
I believe this tube best describes the
sound you are looking for.Although i will
say,telefunkens are the best tubes ever built.

3rd on the vote for the Bugle Boy. Just be careful of "fakes".

my vote is an amperex bugle boy (select). call andy at vintage tube svcs. he sent one to me and it made all the diff in my ls2mk2. i had a siemans nos.....amperex killed it. telefunken would be a good choice too.

good luck