For the EL84, this tube is also 6BQ6 and 7320. Best ever is the Telefunken if you can find them. Then a three way tie with Siemens, Dutch Amperex and Mullard.
For USA 6BQ6, late 1950s RCA black plates are excellent and likely one third the price of Telefunken's.
The 6414, I have no personal experience with these but have heard that the old Raytheon is a good tube, much better than currently manufactured stocks.
The 12AT-7 is easy, Telefunken. If you cannot find Telefunken, the Amperex 7316 is excellent with great dynamics and (usually) very quiet. Good luck with your tube rolling.
For USA 6BQ6, late 1950s RCA black plates are excellent and likely one third the price of Telefunken's.
The 6414, I have no personal experience with these but have heard that the old Raytheon is a good tube, much better than currently manufactured stocks.
The 12AT-7 is easy, Telefunken. If you cannot find Telefunken, the Amperex 7316 is excellent with great dynamics and (usually) very quiet. Good luck with your tube rolling.