I had a request to design a 100watt tube amplifier - that is 50 watts per channel integrated stereo amplifier - and supply it as a kit. I would like to share the progress of the project with the forum.
The first step was to decide on a circuit. That was easy, because I have had good results with the Dynaco circuits.
I looked at the data sheets of KT88 and 6550 tubes. One pair can give 50watts of power without too much strain. From Duncan's tube data (
http://tdsl.duncanamps.com/show.php?des=6550A I got this:
AB1 U/L 40% 436 2x87 2x600 6000 50 1.5 B+ = 500V
I wanted cathode bias, so 50 watts seems completely feasible at 500V on the plate and individual cathode resistors.
I designed the power transformer and checked the values on some software. All seemed well and I started rolling the transformer:
I use 0.1mm mylar interleaving and interleave each layer
Last is the filament windings:
A close up of the windings:
