Supposed to have a high input impedance to preserve the Q of the filter you would place on the input to select your listening frequency. However for some silly reason that I’m not smart enough to see, the input impedance is roughly 2.2k Ohms… how? I’ve done much analysis of the circuit and I expect to see a small signal input impedance that is much higher, and I know this simulator does not take into account the Miller effect and if it does the cascode configuration on the collector of the emitter follower removes any silly business. A current source is supposed to have a really high impedance looking into the collector, yet I still can’t get my amplifier to have an input impedance greater than a few k Ohms. What am I missing?
