I could just bookmark these in my browser, but hey… here they are. If you struggle with complex explanations of how valve amplifiers work, here’s a collection of easy to understand valve amplifier basics from Uncle Doug.
Don’t let the pets and other distractions put you off – there’s really good information in these videos.
Phase Inverters
Output Transformers
Power Transformers
Power Supplies
Triodes & Pentodes
Single-ended amplifier biasing
Double ended biasing (push-pull)
Quad biasing
Cathode Bypass Capacitors
Negative Feedback
Tone Stacks
Resistors
Introduction
Power & wattage requirements
Grid leak, grid stopper
Cathode bias resistor
Plate resistors