I've got a question regarding the 990 inductors. The Re // L combination limits the gain bandwidth product of the diff pair and thereby improves stability without sacrificing noise within the audio band, by shunting the emitter resistors for audio frequencies.
Now my question is: why did they use two inductors instead of one? Production costs and pcb space would obviously be less when using one inductor.
As far as I see the only thing circuit B does in comparison with A is that it places an effective 15 Ohm resistor (with its related voltage drop) in series with the ccs for audio frequencies. But that shouldn't be a problem, is it?
Now my question is: why did they use two inductors instead of one? Production costs and pcb space would obviously be less when using one inductor.
As far as I see the only thing circuit B does in comparison with A is that it places an effective 15 Ohm resistor (with its related voltage drop) in series with the ccs for audio frequencies. But that shouldn't be a problem, is it?
