One point: The feedback resistor influences the character of a tweed amp. A higher resistor gives you a more rawk tone, but on higher volumes you need more damping to have a workable tone. So i made a switchable feedback.
I didn’t know it either, but sometimes its useful to use the search function. Read here:
Post in thread 'Gadget Fuzz Schematic Question'
https://forum.pedalpcb.com/threads/gadget-fuzz-schematic-question.8165/post-73393