Sorry if this is spamming, this is more of an idea I had, since I don't really understand how the compression circuits work. I saw the other day a tremolo effect (automatic variable volume) using an IC 555, a LED, and somekind of photoreceiver that acted as a variable resistor (sorry if got that wrong). My question is would this possible to do for a compression circuit. When the signal gets higher so does the resistor, when the signal gets weaker so does the resistor (higher signal would make the LED shine brighter), that way the signal would, in average, have the same amplitude. I can't really test it, because I don't have the components to do it. Just wondering if it is possible. Again, sorry if this topic is kind of 'spammy'.

 

Hi,

Yes, some optocouplers made for audio use an LED and a light dependent resistor LDR.

 

(Some text removed for clarity.) When the signal gets higher so does the resistor....

The illumination to resistance function is the other way around -more light lowers the resistance.