> > Turns out that adding a high gain but highly nonliniar inverting
> > transistor amplifier stage to the output of an op-amp and taking the
> > feedback to the positive terminal isn't such a good idea even though
> > according to the models of op-amps they teach you at that level 
> it should
> > work.
> 
> 
> Simulation can decieve you, don't trust it!..
indeed it works (once you unbalance it slightly so the simulator doesn't hang) in crocodile clips (which made it all the more puzzling for me at the time.


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