First let us assume that without input signal (Vgen = 0V) the voltage at the output node is also equal to 0V. And now can you tell me what is the voltage at Q2 and Q3 base ?

 

First let us assume that without input signal (Vgen = 0V) the voltage at the output node is also equal to 0V. And now can you tell me what is the voltage at Q2 and Q3 base ?

It's also 0 V.

 

I meant the Q3 and Q4 base after we assume that the Vout is 0V (Q3 and Q3 emitters are at 0V).

 

I meant the Q3 and Q4 base after we assume that the Vout is 0V (Q3 and Q3 emitters are at 0V).

0,7 V?

 

LOL, the voltage at Q3 base is 629.714mV what about Q4 base ?

 

702,386 mV?

 

No, this is wrong. This 702,386mV is a Vbe voltage for Q1. And Q2 Vbe is -702,386 mV.
I've had enough for today. I need some sleep as well.

 

No, this is wrong. This 702,386mV is a Vbe voltage for Q1. And Q2 Vbe is -702,386 mV.
I've had enough for today. I need some sleep as well.

Thanks for all your help. Good night

 

I think I found R1 to be 46,6 Ω

 

I think I found R1 to be 46,6 Ω

Looks good to me