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 favor for some special made transformers, 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 clausbyrith@gmail.com)

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

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).

Designer’s comments
To his great joy, through the years Mr. Byrith has received a number of comments and questions from builders of this amplifier. Enough to motivate a short paper with some comments on the above.

Transformers used in the above amplifier:
Output transformer LL1663/PP
(Also the Output transformer LL1682/PP works very well in this design)

Mains transformer LL1669A