If you already have a B36 I would not bother buying them. Tubes with a grid cap tend to pick up noise on the wire leading to it.
Most GEC tubes sound good if you didn't have the B36 I would say go for it.
In my experience so far, adapters that take two or more tubes can be damn finicky, then add grid wires on top of that and sooner or later back round noise seems to want to creep in.
Since most people are trying to find quiet solutions with their tubes, this just brings things into the equation that do not need to be there.
I know many people have had good luck with the adapters from China, but I am not one of them, LOL. In my opinion you just end up with a shoe box full of adapters that you hardly ever use.
After awhile it seems like a dog chasing his tale...lol
Might as well spend that money on some good tubes that are plug and play in your amp.
the best advise you ever gave was the KISS theory...it is so true...don't over think it.
There are so many tubes to use in this amp that there is really no need to go chasing the next great sound, unless you are a collector of tubes...then by all means ...go and get them.
Heck, save your money and treat yourself to a good driver tube every now and then......the ones that UT has listed above would be enough to last a life time and there is not a bad one in the bunch.
The one tube adapters seem to work fine, the multiple tube adapters from China, one you get them in your amp, you don't even want to touch them, for fear of noise.
I know, you do not have the time to make them anymore because of all of the amp builds that you are busy with...but your adapters are far superior to any i have ever bought from e-bay.
Shamless plug for me to get another 6F8gg adapter from you when you build my amp...with the big brown grid cap....lol
