30W Push Pull amplifier designed by Claus Byrith, Royal Academy of Music in Aarhus, Denmark. 

Claus Byrith is the head of the studio at the Royal Academy of Music in Aarhus. He has a life-long experience from different sound
recording and reproduction equipment.  In 1998 (or was it 1999) we asked Claus Byrith, as a return favour for some special made
tranformers, for an easy-to-build tube amp schematic. It did take some time for Claus to fulfill his promise, but on the other hand
he not only gave us a schematic, but a complete building instruction of a 30W push-pull amplifier, including a comprehensive
theory section which discusses different tube amplifier design issues. 
(Claus Byrith can be contacted directly through email address cb@musik-kons.dk)

The instruction is separated in two parts:
Building instruction (pdf file, 284kb)
and

Appendix (pdf file, 854kb)
with tube data sheets and some classic amplifier schematics with comments.
The appendix also includes performance curves, PCBs and layout suggestions
for the above amplifier (pdf file, 854k).

Transformers used in the above amplifier:
Output transformer LL1663

Mains transformer LL1669A