I have a problem I can't quite figure out.
I essentially want to "buffer" a 50mVpp audio signal to drive a 16 ohm load.
I preferably want to use primitive components so I thought that maybe a Darlington emitter follower might be used.
The problem is that AC coupling, the way I do it, makes the Darlington amplifiers output distort the waveform and massively shrinks the voltage amplitude.
But there is no distortion and no shrinking of amplitude when disabling the AC coupling:
Altough AC coupling works for with a bigger load:
But since I want to drive smaller loads, I tried to see if a Darlington quadruple would work.
And the waveform and the amplitude actually looks a little bit better, but it's still far from perfect:
I wonder why the AC coupling creates this problem for me?
Correction: Actually, the Darlington quadruple was not better in any way. The better wave form was only a result of a higher bias voltage (before the transistors).