The class AB design is done and completed. I have calculated an input impedance of ~6.5k ohm (not sure if this is correct).

The current stage 2 works in simulation and in practice (albeit less gain, getting a 7.4Vptp output). However my calculations here did not take into account the input impedance of the 3rd stage.

The first stage works perfectly in simulation but barely amplifies anything in practice. (I am assuming this is because of the input impedance of the rest of the circuit).

My question/s here are:

1) Is my calculation for the output impedance of the 3rd stage correct?

2) How should I be calculating the resistor values of the common emitter stages while taking the input impedance of the following stage into account?