Voltage amplifier A current signal i at Q15's base gives rise to a current in Q19 of order iβ2 (the product of the hfe of each of Q15 and Q19, which are connected in a Darlington pair). This current signal develops a voltage at the bases of output transistors Q14 and Q20 proportional to the hie of the respective transistor.
Voltage amplifier A current signal i at Q15's base gives rise to a current in Q19 of order iβ2 (the product of the hfe of each of Q15 and Q19, which are connected in a Darlington pair). This current signal develops a voltage at the bases of output transistors Q14 and. Q20 proportional to the hie of the respective transistor