Take a look at the schematic of the 741 on Wikipedia:
Here's my question. Let's say the rails are at +15 and -15 volts and the output of the differential amplifier (blue box in the figure) is
+12 volts. That would mean that the base of Q15 would be at 12 volts, the base of Q19 would be at about 11.4 volts, and the emitter of Q19 would be at about 10.8 volts. That would result in 25.8 volts across the 50 ohm resistor, requiring 516mA of current.However, using the assumed values at the rails, the Q12/Q13 current mirror would only be able to provide a maximum of 738uA, which is 700 times less current than would be required by the emitter output of Q19.
How does this circuit work? What am I missing?