This is not a considered work - it’s an impromptu idea, an impulse.
My writing skills are minimal and I am not an expert at vacuum tube amplifier design.
Formal instruction wasn’t offered on this subject when I commenced my engineering education.
I’ve read about vacuum tubes, both as a guitarist using vacuum tube amplifiers for many years and as a teen constructing and using amateur radio gear (WV6IJE).
My professional background is solid-state circuit and system design.
I’m a retired engineer and have designed many different types of hardware (although my specialty was high frequency/microwave circuits and systems).
I also have many years of interest and experience in woodworking and metalworking.
I’ve accumulated appropriate machinery (plus tooling) to fabricate the mechanical structures required by my various interests, either wood or metal.
Similarly, I’ve acquired adequate electronic test equipment necessary to characterize and test my designs or evaluate modifications and repairs to my musical equipment.
The original motivation for this project was to document how engineers of an earlier time executed the design process - insofar as I could deduce it.
I did apply some modern techniques, in the form of constructing a few spreadsheets, useful for repetitive parts of the design process and minimizing computational errors.
I also used computer circuit analysis simulations to evaluate the performance of circuits discussed here - mainly as a check against the approximations and assumptions that represent a simplified design approach to these niche products.
An audience that I hope to address is the jazz guitarist who is familiar with simple vacuum tube circuits, can read a circuit schematic, has an understanding of how vacuum tubes function, owns some basic equipment for measurement of voltages and currents and a healthy respect for the high voltages always present in these devices.
Those that, for example, find the technical terms unfamiliar, the units of measure unknown and the concepts forbidding should not read this for any reason other than ½entertainment½ or as an incentive for seeking more knowledge related to this subject.
Don’t assume that you can safely, successfully design a vacuum tube amplifier based on my stated opinions without first having some basic knowledge of the topic.