have you read this:
https://www.smallbearelec.com/HowTos/FuzzFaceFAQ/FFFAQ.htm
Steve measures his transistor sets in an actual test circuit. I assume he uses math to figure out his resistor values.
in that article, he tells you exactly which gains work best in the circuit. The problem is that Ge gains vary a lot, so as he says, in order to keep costs affordable, he broadens the allowable gains, thus the tweaked resistor values. Note that those values are for the stock circuit, with fixed resistors. That is why a lot of folks nowadays use a trimmer -- it's adjustable!
anyway, I don't know the exact math he uses, but I measure my transistors for gain, set the bias, then LISTEN ... articles always mention that 4.5v setting, but as you know, actual voltage varies. In fact, I just got through testing an Axis circuit that sounded kinda crappy at 4.5v, but sounds great at 4.8v. Go figure.
anyway, I don't know if any of that helped, but the Peak tester is great for sorting transistors quickly, whether it's Ge or Si, NPN or PNP. you can also use it to verify the pin out if you have any doubts. That allows you to buy stuff like Small Bear's bulk trannies, and save some dough.
https://www.smallbearelec.com/HowTos/FuzzFaceFAQ/FFFAQ.htm
Steve measures his transistor sets in an actual test circuit. I assume he uses math to figure out his resistor values.
in that article, he tells you exactly which gains work best in the circuit. The problem is that Ge gains vary a lot, so as he says, in order to keep costs affordable, he broadens the allowable gains, thus the tweaked resistor values. Note that those values are for the stock circuit, with fixed resistors. That is why a lot of folks nowadays use a trimmer -- it's adjustable!
anyway, I don't know the exact math he uses, but I measure my transistors for gain, set the bias, then LISTEN ... articles always mention that 4.5v setting, but as you know, actual voltage varies. In fact, I just got through testing an Axis circuit that sounded kinda crappy at 4.5v, but sounds great at 4.8v. Go figure.
anyway, I don't know if any of that helped, but the Peak tester is great for sorting transistors quickly, whether it's Ge or Si, NPN or PNP. you can also use it to verify the pin out if you have any doubts. That allows you to buy stuff like Small Bear's bulk trannies, and save some dough.