Prof. Fowler's Fun Stuff
Tube Amplifier Stuff
Capacitor Article - Nice overview of the differences between different types of capacitors
I do this analysis for a transistor amp but the idea is the same for tube amps.
This shows why you need caps between stages... and then the "downside" of having them: highpass filtering
Actually... in most audio applications you WANT that highpass filtering so that downside is not really a downside
Not really specific to tube amps but... a good example of how to use theory to analyze a real-world scenario
Late 1970s booklet that covers only the basics of using a simple scope. None of the fancy stuff not needed for Tube Amps!
Math analysis and test results for the impact of bypassing a 5f1's volume pot