Tube rolling Question

I used the 40s Tung Sol rectifier tube with my Sylvania 6SN7 Bad Boys in the Woo Audio headphone amp with great success. I bought a matched pair of Tung Sols at no small expense just in case. Better safe than sorry. I also used two Herbies Tube Dampers per Tube, one on the glass the other on the base. Again, better safe than sorry. 

I consider spares indispensable.  I just hope my spares stash outlasts me.  I'd hate to have to miss a mortgage payment(proper priorities, and all).

Be very careful of any seller that sells "NOS in white boxes". What this usually means is that the tube tests as NOS but is most likely used. I am not sure if one respondent was suggesting that there exist 6SN7s that were made by Amperex but just for the record Amperex never made a 6SN7. I have seen Amperex branded 6SN7s but these were made by GE. Be very careful of tubes branded Sylvania Bad Boys. The Bad Boy is a great tube but is very specific in construction. Tall, 3 hole black "T" plates with bottom foil getters. Most I have seen were made in late 1951 and in 1962. This is the only Bad Boy made and many ebay sellers are selling Sylvania tubes as Bad boys which are not and quoting an online tube seller who knows (or should) better. Be careful.

An excellent inexpensive 6SN7 tube is the GE short bottle, side getter. Read what Brent Jessee says about them. He makes a comparison to an extremely pricey tube. A friend has a Blue Circle preamp and uses that GE as it was his favorite from all he tried.

Great guidance and directions!!! Thanks One and all. You've given me a lot to look in to. 

Much Appreciated

Happy listening !