Fuzz Face, Vox etc Fuzz adjustments

[Gus]

Over the years I have read many posts and threads about FF like circuits

Now one of the easiest ways to adjust a Silicon FF like circuit is using LT Spice. It will run in Windows, MAC  and Linux(with wine) It is a down load.

Over the years of using it I noticed the 2N2222 and 2N5089 2N4401 etc models in low part count sims often are very close to a build of the simmed circuit.

Another thing that is good about using a program like LT Spice is even if the voltages sim are off some, it is a fast way to learn what each part value change does to the circuit. you can change the transistor model a good thing test is to use the 2N2222 low beta model and the 2N5089 higher beta to see what happen with beta, hfe changes.

Another thing I don't understand is why the web seems to promote 1/2 supply voltage at the 2nd transistor. Others have posted real voltages in different two and three transistor fuzzes from the past, look for the TB2 voltages as an example. Try close to ground and close to supply voltage adjustments as well as 1/2 supply voltage

Also the output collector resistor is not the only one to adjust biasing.
The feedback Q1 biasing resistor changes biasing, 1st stage closed loop gain and can reduce current to the first transistor base. YACK fuzz some Zvex fuzzes
The gain control changes biasing not all are 1K. Vox fuzz 820 under the 1K, IIRC Diaz 2K gain control
The first transistor collector changes biasing, IIRC a roger mayer is under 33K some older Vox are 10K etc. try lower and higher resistor values