And I still like the arrangement (topology) above minus of course the UL accrutements if deploying triodes.
The IT you ask--- strictly speaking not at all necessary---- as conceived it's a 1+1:1+1 device so it's not providing any gain for us--- so what does it do or contribute?
If you view it morphologically--- you should see a CT plate choke (the primary winding) and a CT grid choke (the secondary winding).
Intrestingly, combining these two functions in one device (the quest to universalize :=) has both some advantages as well as disadvantages.
But for now I wanted to point out that in particular the IT ooupled circuit as shown could easily be modified to work well with triodes in both stages of the amp.
Maybee next week sometime I'll ask Kevin to draw up this same essential topology but shown with all triode tubes.
MSL
Builder of MagneQuest™ & Peerless™ transformers since 1989
