Distorting reverb tube

[Tomislaw]

I was surprised that you were glad to see carbon screen resistors - unless you meant that sarcastically

Of course I'm being sarcastic. 

More fun with the amp I mentioned above - 12AT7 as a reverb driver (V2) upsets nearby V1 big time despite both tubes being individually decoupled and sitting on different supply nodes. Curiously enough - 12AX7 works perfectly fine there at any preamp output level. I got rid of all problems with hum/buzz, but I had to rebuild the whole thing.