Thanks guys for the thumbs up
With modern computers and simulation software, its really not that difficult to design and build, triodes are the most simplistic circuits in audio. I used a free program called LTSpice, tons of support in the forums with plenty of tube models.
The magic is in the magnetics!
I'm self taught in electronics, education consisted of a 4yr apprentice program in Electrical Construction, 1st yr was theory but nothing to do with tubes or transistors. 30 years in the audio hobby did help somewhat.