After spending more than I care to admin on NOS Vintage 12AX7 tubes, and having so many be noisy, I found that the new production Gold Lion's were one of my favorites and dead silent. I realize right now they might be harder to get but it sounds like the Russia ban has been worked around. If you really want to go the vintage route, I would call up Brent Jesse or Jim Mcshane or your favorite vendor and they can select something quiet out of their stash.