Hey,
I'm new to the forums so please excuse my jumping in on this thread. I'll briefly say that I had issue with my EZ81's with my Mini T. and ended up getting some NOS ones from Brent Jesse and have not had any problems since...I got my Mini in January. GREAT amp btw!
And I think others have had issues with their JJ EZ81's SO, it's not really Decware's fault (I know knowone has pointed fingers or anything) . I think there is an unreliable batch of EZ81's out there and some people are getting stuck with them. I tried 3 different batches of JJ's...they all were a no-go!
NOS rectifiers don't go for very much either and you can read a bit, or ask around about the different manufacturers who made them and see what flavor might work best for your set up

I've got a set from Valvo and I think Mullard.
Have fun

-H