Phono preamp tube rolling.

pindac, what’s your 6SN7 keepers ? For what preamp ?

Check out Kevin Deal's videos on tube rolling.

I enjoy tube rolling, but there are three 12au7 tubes that I keep in a virtual rotation in no particular order: Mullard, Chelmer, and Telefunken. These three are consistently quieter than a lot of other tubes. 
I have a small collection of 50s, 60s GE, RCA (clear top in particular) that become noisy with ghosting and microphonics after a fairly short number of hours.
Stick with my three recommended brands and you will be rewarded with stellar sound and stone quiet performance. 
My favorite of the three? Tough call, but I really like the Chelmers, and you can't beat the price!

Chelmers would be relabeled tubes from a large maker - could be USA or China. Probably USA if small signal. I had an old Hagerman Trumpet (wood tower type) that was supplied with Chelmer 6072 (12AY7) which looked like they were either old-stock Sylvania, RCA, or GE black plates.

The 6SN7 Tubes I have retained for use are Kenrad VT231 Black Glass and a Sylvania GT Tube.
These are different in their presentation as an interface where they the input Tubes on 845 Monoblock Power Amp’s.

I would very much like to try other Vintage, and will most likely return to this when the Mono’s are converted to a Balanced Design.