WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
There's a lot of information in the Radiotron Designer's Handbook on the design of audio transformers of various types and constructions. Copies may be available on CD from AudioExpress (was Audio Amateur?).
However, the practical difficulties involved in making sure the windings are balanced and so on might make them difficult for the enthusiastic amateur. If you have access to professional winding equipment and the appropriate core material, you might be able to do it.
Thanks Janey for the reply......this is one of the pages y have visited yet,but those calculations are for single ended output;and the link it has is in Croatian...(my Croatian is very poor).
Any other suggestion?Thanks again.
The design of audio transformers as to the inductances and so on is relatively easy. The difficult bit is deciding which construction method (random, layered and sectional) to use and how to go about it.
If you want the relevant pages from the Radiotron, I could copy them and send to you.
My email address is in the information section here.
For best performance you need sectioned windings, with primary sections wired in parallel, and secondary sections wired in parallel.
All paralleled sections need to have EXACTLY the same number of turns, or else you will have shorted turns. THIS WORKS !.
This technique averages induced flux density and gives reduced distortion.
If you hunt, you may find a paper copy of The Radiotron Designers Handbook, but they are sought after and expensive.
There is a cd-rom reprint version too.