Stereo transmitter using AM for the R channel and PWM for the L channel.
What I've done is, first I generated a PWM of the source at the top of the schematic, then i used the PWM signal as a Carrier signal for the amplitude modulation...
And for the demodulation, the upper OpAmp extracts the PWM signal and feeds it to a simple (too simple) lowpass filter which demodulates the signal, same for the AM demodulation...
