This assignment we have been given has been causing me major headaches. I feel like I'm finally close to getting this amp to work after hours of fiddling around, but now I've found the output is clipping at a very low voltage. It must have a differential input and a class AB output. Minimum of 1500 voltage gain. Stability and wasted power aren't a concern, as long as I can write up where power is lost.
I'm sure there's enough base current, and don't think there's any loading, but there is no voltage swing available at the output.
What is causing this clipping?
I'll buy a pint for anyone who can get this thing to work. I want to understand where I'm going wrong, I just can't work it out for the life of me.
Thanks for looking!
Scope with DC coupling shows the following waveforms. The left hand one is the base of Q11, and the right hand side one is the load output (before cap). It seems like together they make a full sine wave.. What is going on???
Edit 2: Here are both waveforms on the same scope: red output, blue input to Q11.