I would have guessed that too since V12 & V13 are 12AT7s. I have a couple of these guys. One is about 85% working the other is dead. I'll probably dig into restoring the working one properly soon.
What I'd like to know is how do you go about calibrating one of these? There is an adjustment for vertical linearity for example. Should it be hooked up to a known good TV and do it visually
