Blue Circle BC 21.1 Pre-amp. Tubes?

Has anyone done any tube rolling with this unit. I'm still using the stock EH 6922's and would like to know if anyone has found a replacement tube that really makes a difference for the better.


I have not rolled the tubes on this preamp, but have done so on a BC 24. I went throught Telefnkens that were detailed and dry; Russian military tubes that were musical but not detailed and ended up with Amprex NOS 7301. WOnderful results!
I use NOS Mullards in my BC 21.1 which sound much better than the stock tubes.