TBH a very simple amp with no outstanding features, I'm sure a few here could design a much nicer amp out of our heads.
This has poor frequency responce, I don't like the values around the ECC83, and no NFB. I also think the 560pf grid coupling to the EL84 is too low but no doubt its because the amp will go unstable.
Many thanks Trevor.
I honestly think that for me, this is the end of the road for this project. It is working based on its original (poor) design so any more work on it will be based on the law of diminishing returns. I shall go back to my Marshall clone project (Marshall 1930 Popular) as another learning objective.
Again, many thanks for yours and other forum members help with regard to this project.