Download: PAK-Course-100-series-D+R It's a comprehensive introduction to solving a BJT Common Emmiter stage for large signals using the W-function. It includes all the maths working. Great fun! Maybe AI should like to learn this skill?

Download: PAK204 Push-Pull CE stage spreadsheet to demonstrate the W-solution. 

There is also an LTspice file for PAK204 Circuit. Click on the RHS link PAK204asc to view the code.

(To run it, Copy/paste into a plain text doc and change the suffix to .asc). BTW it's for Archive.org.
Alternatively download IansPAKproject.zip for all PDFs and LTspice asc files in one file.

Download: PAK402 Push-Pull CC stage spreadsheet This is the Follower or Common Collector version.

The LTspice file for PAK402 Circuit is on the RHS link PAK402asc - see above to download all in one.

Download: PAK411 DoubleCross stage w-solution.

The LTspice file for PAK411 Circuit is on the RHS link PAK411asc - alt. download the all in one file.

Download: PAK412 CC DoubleCross w-solution

The LTspice file for PAK412 Circuit is on the RHS link PAK412asc - alt. download the all in one file.

Download: PAK312 CFA analysis Solves the basic CFP (Complementary Feedback Pair) using the w-function, then provides equations for the CFA topology that is a complementary form of the single ended CFP. The standard explanation that “the error signal is a current into the inverting input” is shown to be incorrect using first principles analysis. An explanation of how the experts got it wrong is also discussed.