After travel to find any interest websites and schematics on the internet,

I just found out the great website that contain many nice articles.

http://lilienthalengineering.com/

Kurt van Lilienthal Heitmann Thaaning Steffensen is a founder of Lilienthal Engineering.

Highlight for me is an article name “100 power amplifiers to lift your hat”.

http://lilienthalengineering.com/100-amplifiers-chapter-1/100-power-amplifiers-to-lift-your-hat

Founder said “I have made the 100 amplifier list with a little help of the highly skilled and knowledge members of the “Sound Practice” magazine forum “Soundlist” aka “The Joe List” and participants of the European Triode Festival. I asked them to suggest amplifiers they felt should be on a list of the 100 best or most interesting audio power amplifiers.”.

I think all 4 parts of this article such a milestone that him said.

This is a history of audio power amplifier from past to present and must develop through the future.   

Thanks for did this great compilation.
I think people who interest in audio especially tube amplifier should be read and understand.
Cheers!!!