Introduction
Recently I was asked about whether I could write on my blog about how to design a filament bias stage. My immediate answer was:
- I don’t have much time these days am afraid to write extensive articles (and sometimes to even write-up at all)
- Thomas Mayer has written about it (see here). Of course, I completely forgot that Thomas never completed his intended series of posts around filament bias, so I decided to attempt explaining the practical aspects of its design in this blog.
Before you continue reading this post, I suggest you read first Thomas’ article above and get yourself acquainted with DHTs and triode amplification. I’m not going to cover any of that theory which I will give it for granted that the reader is experienced with valve circuits and in particular with the hybrid mu-follower amplification stage with gyrator load.
3A5 DHT example
Continue reading “Filament Bias: a practical example with 3A5 DHT”