In that tube family E88CC/E88CCa/6DJ8/6922 you have a plethora of choices. Many of the best tubes are no longer being made and are available NOS at premium prices. If you get NOS it's best to buy from a reputable dealer, especially if you are just starting out with tube gear. It is difficult to say exactly which tube will work best in your amp, in your system, in your room, to your ears, with your musical preferences. That said, of the NOS tubes in that family two of the favored flavors at the high end are both German made and pricy (read: $50-100 each!) are:
Siemens Halske E88CCa
Telefunken E88CCa
There are many counterfit tubes out their of these types/brands so again, best to buy from a reputible dealer if you don't know how to spot a fake.
For less money (about $35 each) some folks have been happy with the Soviet Rocket tube which is a 6H30, and is a substitute for the 6DJ8 family. It will not work for all applications as something in the design is slightly different, but I cannot recall what. Check with the tube dealer for your application and see what they recommend. I think JJ Tesla does indeed make some great tubes, but have never heard their E88CC recommended highly over the competition, but have also never tried them out myself.
My personal preference for tube dealers is Jon at The Tube store up in Canada. There are other fine dealers which you can get recommendations for here and on AudioAsylum. Jon has never let me down so I stick with him.
Siemens Halske E88CCa
Telefunken E88CCa
There are many counterfit tubes out their of these types/brands so again, best to buy from a reputible dealer if you don't know how to spot a fake.
For less money (about $35 each) some folks have been happy with the Soviet Rocket tube which is a 6H30, and is a substitute for the 6DJ8 family. It will not work for all applications as something in the design is slightly different, but I cannot recall what. Check with the tube dealer for your application and see what they recommend. I think JJ Tesla does indeed make some great tubes, but have never heard their E88CC recommended highly over the competition, but have also never tried them out myself.
My personal preference for tube dealers is Jon at The Tube store up in Canada. There are other fine dealers which you can get recommendations for here and on AudioAsylum. Jon has never let me down so I stick with him.