My 6922 Tubes Are Too Bright!

This is a good source/overview of NOS 6922. You can use it to find tubes suiting your sound preferences.

https://www.audioasylum.com/audio/faq/joes-tubes.html

I agree with whart. Try the new production Mullards. they are warmer sounding and not expensive. 

I was not aware that Mullard made a new production 6922/6dj8. Where were these found?

@buellrider97 excellent post thank you. My preamp uses six  6DJ8 tubes so cost is always a factor for me. Currently using the 7DJ8 Masuhitsa/National Union tubes from Upscale, I would not call them warm to me they are very neutral extended at both frequency extremes and quite well balance. Also excellent for the money. My preamp is not bright at all BTW as always it's not just the tube also the implementation!

Mullard does not make tubes anymore.  Electro Harmonix (EH) owned by an American makes EH, Mullard, Genelex and Tung Sol tubes in a factory in Saratov Russia.  The Mullard, Genelex and Tung Sol tubes have nothing to do with the original brands other than using their names.  New production tubes also come from China.

That's not to say that the EH Mullards are bad tubes, many people like them and they are much cheaper than NOS tubes.  Also, all the old stock tubes would have been used up by now if there wasn't current production tubes.  So give them a try, if you want, you won't be out a lot of money if you don't like them.