My only problem is that I cannot identify any input or output signal

The input is to Q1 of the original circuit, and the output is the junction of RE1 and RE2 (which is close to the amp's output voltage since it's at the drive to the emitter-follower output stage).

 

The formula for the op amp (RF2 + 1)/RF! does not work,

That is because that equation is incorrect. You have the "+1" in the wrong place.

First, do not start with specific resistor values in the equation. Get the form of the equation correct, and then substitute in some actual component values.

From post #13, Non-inverting gain equation: Av = (RF2 + RF1) / RF1

This can be restated as: Av = 1 + (RF2 / RF1) (as in post #9)

Note how this is different from what you posted in the above quote. 1 is added to the entire quantity (RF2 / RF1), not just RF2.

ak

 

If you set RF2 to 1k, the same as RF1, the voltage output becomes 2k. The formula for the opamp (RF2 + 1)/RF! does not work, the formula (RF2 + 1k)/RF1 does, why is this?

Because the gain formula for a non-inverting op-amp is [(Rf / Ri) + 1] which is equal to [(Rf + Ri) / Ri]. You must be careful about the brackets. Your second formula works because RF1 = 1k therefore (RF2 + 1k) / RF1 is the same as (RF2 + RF1)/RF1 which is the second way of expressing the op-amp gain.